TER VERKRIJGING VAN DEN GRAAD VAN DOCTOR
IN DE WIS- EN NATUURKUNDE AAN DE RIJKS-
UNIVERSITEIT TE UTRECHT OP GEZAG VAN DEN
RECTOR-MAGNIFICUS DR. H. TH. OBBINK, HOOG-
LEERAAR IN DE FACULTEIT DER GODGELEERD-
HEID, VOOR DE FACULTEIT DER WIS- EN
NATUURKUNDE TE VERDEDIGEN OP WOENSDAG
3 JULI 1929, TEN 4 URE N.M.

Na de voltooiing van mijne monographie over bet geslacht Ariatida, waarvan het
eerste deel als proefschrift verscliijnt, maak ik gaarne gebruik van de gelegenheid
mijn dank te betuigen aan allen, die op de totstandkoming daarvan invloed
hebben gehad.

In de eerste plaats ben ik U hartelijken dank verschuldigd, Mooggeleerde Pulle,
Hooggeachte Promotor, voor uwe groote welwillendheid, de keuze van het onderwerp
geheel aan mij te hebben willen overlaten en door liet beschikbaar stellen van
ondej-zoekings-materiaal mij bij de bewerking te hebben gesteund.

Zeergeleerde Goetiiart, Hooggeachte chef, ü hebt gedurende den tijd, dat ik als
conservator aan \'s Rijks Herbarium werkzaam ben, mij ter zijde gestaan met alle
hulpmiddelen diejiet Rijks Herbai\'inm kon verschaffen. U ben ik grooten dank
verschuldigd, niet alleen voor uwe kritiek bij het bespreken van verschillende
vraagstukken, maar ook voor uwe groote hulpvaardigheid bij het oplossen van vele
moeilijkheden van technischen aard, welke aan het vastleggen der typen door
middel van foto\'s verbonden waren. Uw groote belangstelling daarvoor zal mij
steeds bijblijven.

Hooggeleerde de Graaff, geachte vriend, U dank ik voor de belangstelling die
gij mij hebt betoond en voor de prettige wijze waarop ik met u mocht
omgaan. Veel ook mocht ik van u leeren tijdens de vele aangename gesprekken,
flie ik met u voerde op onze gezamenlijke studiereis in Zuid-Frankrijk, waaraan ik
steeds aangenaam terugdenk.

Hooggeleerde Moll en Schoute, U dank ik voor het onderwijs in de plantkunde
dat ik als student van U heb ontvangen en voor het vele dat ik onder uwe leiding
heb geleerd.

Ten slotte wil ik gaarne dank zeggen aan allen, die door hunne onmisbare
medewerking bijgedragen hebben tot het ontstaan en beëindigen van dit werk,
ook aan alle buitenlandsche geleerden en vakgenooten voor hunne warme belang-
stelling tijdens de bewerking. Met diepgevoelde dankbaarheid herdenk ik hier mijn
overleden vriend Prof. Eduard Hackel, den grooten Oostenrijkschen agrostoloog,
die het vooronderzoek met zooveel interesse heeft gevolgd en de voltooiing van
het werk niet meer mocht beleven. Ik beschouw het als een groot voorrecht, dat
ik zoo vaak met dezen grooten geleerde van gedachten heb kunnen wisselen op
onze wandelingen in zijn geliefd Alpenland.

In a preliminary work: „A critical Revision of the genus Aristidaquot;, I have given
a review of all the hitherto described species of this genus with the citation of the
literature,quot; the exact copies of the authentic descriptions and the figures of the
spikelet-characters, taken from the typa specimens so far as I could locate them
In many cases it was necessary to enter into critical observations, because the
nomenclature and the ideas found in the different manuals are exceedingly entangled.
The Revision, although very important for botanists who wish to know the exact
data of a fixed species, is not to use if we wish to determine an arbitrary plant
of our genus, therefore we must have a monograph and I indicated already that
it was my intention to write such a work. I must however observe that this work
differs somewhat from other monographs and that it is in the first place a practical
manual to the knowledge of this very difficult genus. It contains descriptions of
all the species I have accepted as valid and keys for their determination. I was
therefore obliged to omit in this work all the data already given in the Revision
and to take into consideration that, with this monograph before us, we must, after
being somewhat familiar with the genus and the different characters, without great
difficulties, get a clear idea of it and with the keys before us find the name of a
specimen belonging to our genus. It is therefore advisable to read the chapter where
I have treated the diilerent characters used for the limitation of the species. Ana-
tomical characters are for practical reasons not taken up in the keys. No attempt
is made to bring the allied species together in groups, because such groups are not
easy to limit and the habit of such groups is scarcely to explain in a key. The
keys to the species of each section are thus entirely artificial. On the other hand
there are in our genus many very striking morphological characters of great con-
stancy we can use with profit in the keys to recognize the species. American
authors have divided the sections of a genus they studied, into minor groups, each
group received a name, which was the plural of the most characteristic species of
the group. In our genus we can give t\\\\e n\'a.me^ o{ ^ripariae, cognatae, purpurascentes,
adscensionesquot; to the groups containing all the allies of Aristida cognata, riparia^
purpurascens etc. The monographer recognizes these different groups often by indefinite
characters of growth, colour or habit in general. I have therefore not accepted in
this work the method of American botanists.

Aristida is indeed a very difficult genus, not because the characters of the plants
are difficult to understand, but because all the characters were taken hitherto — and
there was no other way — from dried specimens, which are often damaged in

course of time. I found an enormous diversity in the genus Aristida and althouoh
I studied about 15000 specimens, I could not expect to settle the characters defi-
nitively. No attention was given by taxonomists to the numerous intermediate forms,
and hybrids were never observed or indicated in the literature of our genus. I am\'
convinced that these hybrids occur in greater abundance than I have hitherto found
m the different herbaria, For the knowledge of our genus in the future, agrosto-
logists must study the species in the field and also by cultivation. Field study is
very important when different species grow together and we can study and collect

the intermediate forms. This was already done accidentally by some famous collectors

but no attention was given to the facts. Cultivation is also very important, not only
to know somewhat more about the constancy of different characters, but also because
we get quite undamaged specimens at our disposal. We know that the glumes and
the awns are very fragile in our genus and that it is not always possible to give
the different exact data of a species from herbarium-specimens. The different
characters of the glumes and awns are in the future to verify with the livino-
specimens.nbsp;^

In the liistory of our genus we can distinguish four periods, the first period runs
to the year 1753 when the genus was described by Linnaeus, the second period
from 1753 to the publication of the „Essai d\'une nouvelle Agrostographiequot; by Palisot
he Beauvois in the year 1812, .the third period from 1812 to 1842 when the Russian
monographers Trinius and Rupreciit published their Species graminum Stipaceorum,
the fourth period from they year 1842 to the publication of the Critical Revision
of the author.

In pre-linnean time there was but little known about grasses of our genus. We
find in the old literature for the first time in the year 1696 a grass mentioned by
Plukenet 1) as „Gramen macleraspatanum avenaceum panicula sparsa aristislongis ornata\'\\
This grass is the Indian Aristida Hystrix, afterwards described by Ltnne\'s son. In
the year 1696 we find once more a grass in Sloane\'s 2) Catalogus and History as
„Gramen avenaceum panicula minus sparsa, cujus singula grana ires aristas loyigissimas
habentquot;, with the locality Funchall in ins. Madeira. It is not exactly known if this
grass is the annual A. adscensionis or the perennial A. coertdescens. In the year 1703
TourneforI\'3) mentioned a „Gramen orientate tomentosum, spicatum, minus, aristis
pennatis:\' This is undoubtly the Oriental Aristida plumosa. We now come to the
year 1753 the beginning of the important second period with Linne\'s Species Plantarum
and the publication of the genus with the only species Aristida adscensionis which
is therefore the type. Although Linnaeus cited in this work the phrase-names of
Plukenet and Sloane, he described the plants collected on the Island of Ascension
by OsBECK. The citation of the grasses from Plukenet and Sloane is incorrect.
In the works of Linnaeus we find, that he described four species of Aristida. The
Aristida adscensionis is universally accepted as the type of our genus, Tournefort\'s
grass, mentioned above, was described by him as Aristida plumosa and belongs to
an important section of our genus. In the Systema Naturae ed.X., he described in
the year 1759 his Aristida americana, which is a very different species and belongs
to the genus Bouteloua. The fourth species is Aristida artindinacea, described in tlie
Mantissa plantarum altera in the year 1771. It is very curious that Linnaeus
desci-ibed this plant as an Aristida, because Linnaeus gives in the diagnosis the
,,calyx sub-5-floris, 2-valvisquot; and we have thus before us a genus of a quite different
tribe, the Festuceae; in the genus Bouteloua the spikelets are 1-flowered with a
3-awned rudiment and Linne\'s conception is thus easy to explain, but in Aristida
arundinacea there is not a single character present, to place the plant in our genus.
Linne\'s plant was described as Arundo madagascariensis by Kunth and in the

year 1897 accepted by Hooker as a distinct genus, he called Neyraudia. Although
this genus is much allied to the genus Triodia, I think that it is better to keep it
separated and to name the plant Neyraudia arundinacea (L.) Henr.. In this second
period many new species of Aristida were described, among them many we accept
as valid species in modern time. It is noteworthy that Adanson gave in the.year 1763
to our genus the name of Kielbul In this linnean period I mention here the following
authors: Forskal (1775), Linné f. (1781), Retzius (1786), Walter (1788), Lamark
and SwARTZ (1791), Tiiunberg (1794), Desfontaines (1798 and 1809), Cavanilles
(1799), Michaux (1803), Willdenow (1809), Poiret and R. Brown (1810). The third
period begins with the valuable work of Beauvois and in this work, already mentioned
above, we find different new genera, at first the genus Gurtopogon, which was based
upon the Aristida dichotoma of Michaux, this is an Aristida with very shoj-t erect
lateral awns and a central awn which is spreading and spirally coiled at the base,
this grass was named Avena paradoxa by Willdenow and cited under this name
by Kunth. Another genus of Beauvois is Arthratherum, based upon Aristida hijgro-
metrica and stipoides ot Rob. Brown and Aristida pangens of Desfontaines. Here
Beauvois mentions the articulated awn as a generic character, agrostologists have
afterwards accepted this genus of Beauvois as a very distinct section of the genus
Aristida. Beauvois\'s concept of Linne\'s Aristida was entirely false and he probably
accepted Linné\'s Aristida plumosa ihe type of the genus, although he cited
lanata, a species described by Forskal and indeed allied to Aristida plimosa. So it
is to understand that Beauvois gave a new name Ghaetaria to those species of
Aristida which have naked awns. Under Ghaetaria, which is thus a synonym of
Linné\'s Aristida, 25 species are cited by Beauvois, some of them with a? Modern
authors have accepted the name Ghaetaria for a section of Aristida. In this period
we find many new species described by: Delile (1813), Humboldt, Bonpland and
Kunth (1815), Lagasca and Elliott (1816), Muhlenberg and Roemer and Schultes
(1817), Roth (1820), TRiNiusap. Sprengel (1821), Labillaediére and Torrey (1824),
Gaudichaud (1826), Trinius, Kunth and Nees (1829), the latter described in his
Agrost. Brasil. many new species under Ghaetaria; Presl (1830), Nees (1832), here
the genus Stipngrostis was de.scribed, and recognized as a very distinct section by
other authors. Kunth (1833), Decaisne (1835), Tausch and Trinius (1836), Savi
and Nuttall (1837), whereas at the end of this period Nees described in the
year 1841 a great many different species in his African flora under Stipagrostis,
Arthratherum and Ghaetaria. He placed all his species together with the genera Stipa
and Lasiagrostis in the tribe of the Stipeae.

In the year 1842 a famous work on the genus was published by Trinius in
conjunction with Ruprecht. This work is an example of extraordinary exactness,
a work that testifies to the talents of the authors, it is of the greatest value to
agrostologists and a guide to the knowledge of the genus Aristida at that time. In
this work: Species graminum Stipaceorum are enumerated and described 98species
of Aristida.^ these are divided into the following sections:

A few species taken up here do not belong to this section and the authors
overlooked some characters or they had not sufficient materials at their disposal.

§ 11. Arthratherum P. B. ref. Aristae caducae setis nudis. There are 9 species
mentioned under this section, all belong to this tribe.

§111. Stipagrostis N. E. ref. Aristae caducae setis pennatis (Aristida P. B.). The 18
species mentioned under this section belong for the greater part to this tribe, a
few ones belong to the group where the lemmas are articulated at the middle and
these species are accepted as belonging to a dilferent tribe. The excellent descriptions
of these eminent authors are much better than many diagnoses of species given
in modern time and we find in their book a great many valuable observations,
the study of this book was therefore the starting point for the knowledge of the
genus. Since the year 1842 a great many other species were described, but a
revision of the whole genus was never undertaken. T will enumerate hero in
chronological order the principal authors of the new species and the arrangements
given in some of the valuable manuals.

In the year 1851, a genus Schistachne was published by Figari and Denotaris,
based upon Aristida ciliata of Desfontaines. The striking character of this genus
is that the lemma is articulated at or above the middle and the awn is thus
deciduous with te upper part of the valve. I have taken up this genus as a very
distinct section of Aristida.

Eugeworth (1848), Scheele (1849), Jaubert and Spach (1850—53), Steudel (1854).
fii his Synopsis Plantarum Graminearum we find under Aristida that Steudel
copied the 3 sections of the Russian monographers, 144 species are accepted by
him, many of them are however not valid.

Mociistetter (1855), F. von Mueller (1855), Cosson and Balansa (1858), Munro
(\'I860), Andersson (18G1), Edgewortii (1862), Grisebacii (1866), Welwitsch and
PiiiLippi (1871). In the year 1878 Doell\'s Gramineae for the great Brazilian Flora
founded by Martfus were published. The genus Aristida with 18 species is divided
here into 2 sections: A. Bhabdatheron, where the lemma bears a not or slightly
twisted, short or wanting prolongation. The other section B. Schoenatheron has a
well-developed strongly twisted column.

Both sections are not sharply to limit and Aristida recurvata and A. riedeliana,
both belonging to the section Rhabdatheron according to Doell, have a very distinct
twisted column, some of Doell\'s species of the section Sc/ïoma^/îeron have only a very

short, not or scarcely twisted column. In the section Ghaetaria there are all transitions
from a short strict beak at the summit of the lemma, to the very long densely twisted
column of some species and we cannot use this character for the sections, although
it is valuable to recognize dillerent species. Let us continue our chronological
series with Oiiapman\'(1878), Bentham (1878), Thurber (1880), Ascherson (1880.),
Regel (1881), Fournier (1881). We now come to Bentham\'s Notes on Gramineae

in the Journal of the Linnean Society, Vol. XIX. (1882) p. 14. Here we find the
system I mentioned already at the beginning of this chapter, the genus Aristida
was „divided into 3 fairly marked sections which Beauvois, Nees, and others have
raised to the rank of generaquot; says Bentham, the sections we accept are however
given by Beauvois and Nees as genera and afterwards proposed as sections by
other botanists, this is something else. Bkntham has copied the ideas of Trinius
and Rupreciit and misunderstood the genus Schistachne, giving no attention to the
important character of the articulated lemma. In the following years many other
species of our genus were described by different botanists. Vasey (1883),
Engelmann (1884), Boissier (1884), Vasey (1880), Trabut (1887), Battandier and
Traeut (1888), Hackel (1888 and 1889). Boissier gives the same 3 sections as
Bentham but in the section Arthratherum he includes A. cijanantha which is a
member of the Chaetaria-gYOM\'ç, and A. Schweinfurtldi where the articulation is
placed at the summit of the column and therefore belongs to another section. I
must observe that the treatment of the section Slipagrostis is not exact, under the
species where all the awns are feathery he placed A. acutiflora and A. Zittelii,
both have however quite naked lateral awns. Boissier used in his key the articulated
lemma to distinguish Aristida ciliata.

Staff (1892), Terracciano (1892), Vasey (1892, 1893, 1894), Cosson (1895),
Robinson and Greenman (1895), Hackel (1895), Spegazzini (1896), Franciiet (1890),
Stapf (1899), Rendle (1899) and Chiovenda (1899).

Chiovenda\'s work on the grasses in the Flora della Colonia Eritrea is important
because here is given under Arist\'da a better arrangement. We find in this work
4 sections, the first one is Ghaetaria, but here Aristida liordeacea is included and
the characteristic articulation overlooked, for the. first time there is given great
attention to those species of Aristida where the column bears an articulation at
the summit just below the branching point of the 3 awns. This section was named
by him Pseudo arthratheum. Chiovenda accepts the column as a part of the lemma,
he says: „gluma III in V2 superiore convoluta et ad apicem articulataquot;.

In the year 1912 Chiovenda uses for this section the name Pseudarthratherimi,
a name I have definitively accepted for this section.

Lindman (1900), Nash (1900-1903), Hackel (1900-1912), Scribner and Ball (1901),
Litwinow (1902), Arechavaleta (1903), Pilger (1903-1915), Chiovenda (1905,1912),
Bailey (1907), Vierhapper (1907), Stapf (1907, 1910), Hitchcock (1909, 1912—13)^
Domin (1911), Ekman (1911), Wooton and Standley (1913), Hubbard (1913)\'
(30utinh0 (1914).nbsp;v

In the year 1915 Domin\'s important study on the flora and plantgeopraphy of
Australia was published and in this work we find important data on tlie genus
Aristida. The Australian Aristidas were divided by him into 5 sections. His section
Arthratherum is the section as commonly accepted by agrostologists. A second
section was named by him: Holatherum with the description: „a sectione praece-
dente differt aristis continuis, a glumella haud articulatisquot;. This section agrees.

perfectly with Doell\'s section Schoenafheron, see my observations on this section
already given \'above.

His third section is Streptachne with the diagnosis : „arista a glumella haud articulata\\
arista trifida sed ramis valde inaequalibus, lateralibus abbreviatis, submdlisvel inferdum
nullisquot;. As already explained by me, this section is accepted in the monograph.
I am quite of the same opinion as Prof. Domin that we cannot unite the genus
Streptachne with the genus ^^z^a. Domin indicates that many American Aristidas
belong to this section, as Aristida scabra, A. jorullensis and A. schiedea.na, other
species as A. tiihrculosa and A. californica do not belong to this section but are
true members of the section Arthratherum. The following section is the well-known
section Ghaetaria. New in Domin\'s work was the section Arthrochaetaria with the
diagnosis: „iit Chaetaria, sed aristae a glumella conspicue articulatae.quot; The species
mentioned by Domin under this section, and I could study the authentic specimens,
have no articulation at all, a special tissue was not present and the supposed
articulation proved to be erroneous. The section thus had no basis and I was obliged
to accept for this group of Aristidas, hitherto only observed in Africa, a new name
Pseudochaetaria.

Since that time, we find in the literature no other arrangements, although many
new species were described by Mss. Camus (1919, 1926), Mez (1921), Chiovenda
(1924) and Hitchcock (1924). During the revision of the genus many new species
were found by me in the different herbaria placed at my disposal and among the
sets I received from different agrostologists. Prof. Mez described 29 new species,
only 12 of them are accepted as valid in my work, 12 species were already
previously described by other botanists, 3 species were a mixtum of dilïerent already
known species, and 2 are hitherto doubtfull. In the year 1924 Hitchcock published
a revision of the North American species of Aristida. He divided the American
species into 3 sections. Besides Ghaetaria and Arthratherum he proposed for the group
with very short or wanting lateral awns the name Uniseta. This name is super-
fluous, we have for it Domin\'s name Streptachne. Nearly all the authors have a
great tendence for uniting different species, without taking into consideration the
geographic distribution and the existence of hybrids.

Bentham and Hooker placed our genus in the Genera Plantarum Vol. HI. (1883)
p. 1076 in the tribe of the „Agrostideaequot;, a tribe they divided into 4 subtribes
and Aristida is there a member of the first one, the Stipeae. Sharp characters to
recognize these subtribes are not given by these authors. The shape of the panicle
is a character too variable to separate the subtribes, the prolongation of the
rhachilla beyond the floret occurs not only in the Phleoideae and Euagrosteae but

a SO in a niember of the Sporoholeae^). Generally the rhachilla is not produced in the
S/zpme and there is nearly always but one flower in the spikelets. Rarely however there
occur two-flowered spikelets. Nees^) mentioned such flowers in Aristida namaquensis
(yarietatem memorabilem spiculis nonnullis bifloris at Platklip le-it Drè-e^ and \\
observed such spikelets in different North American species of the section C/.a.^an«
but m all the cases only a few flowers had two well-developed lemmas each
lemma bearing three awns. Such a spikelet has a very curious aspect, but these
anomalous flowers are rare among hundreds of normal ones.

The subtribe Stipeae as it was accepted by Bentham and Hooker is very hetero-
geneous because such genera as Muhlenhergia, Brachyelytrum and Pereilema are
placed together with iStipa and Aristida, although the texture of the lemmas is
used to make two opposite groups. Hackel3) accepted the tribe Agrostideae of
Bentham and Hooker and also the subtribe of the Stipeae but he placed there
many other genera as Amphipogon, Nassella, Pi,ptochaetium and Podophorus. It is a
act that many agrostologists were not satisfied with this system and found it better
to divide the large tribe of the Agrostideae in more natural groups So we fmd in
more recent literature two tribes the and the A^rosto, accepted for instance
by Stapf and by Ascherson and Graebner. All the genera with an indurated
emma must be placed in the tribe of the Stipeae, those with a membranaceous
lernma in the Agrosteae. A genus as Muhlenhergia comes therefore in the Aqrosieae
and the affinity with the genus Sporobolm is better to express.

In the tribe of the Stipeae the articulation is without exception placed above the

or the margins at least involute. This group of the Stipeae is a more natural one

without difficulty in this tribe. Even the genus Aciachne, altliough very anomalous
nnds its place here.nbsp;\'

The genus Ortachne, described by Steudel in 1854, with the only species 0. re/or^a
Nees, does not belong to the Stipeae, the lemma is of about the same texture as
the glumes. This species is the same as Stipa rariflora Benth., it was for reasons
ot prionty called Ortachne rariflira by Mss. Hughes (Kew Bulletin 1913 p 30^),
there :s no articulation between lemma and awn, this, in connection with the
texture of the_ lemma excludes it from the genus Stipa. The genus Ortachne, if we
will maintain it, must be placed under the Agrosteae, ne^itio Muhlenhergia. knoihev
genus, described by R. Brown, is anomalous, it is the genus Streptachne with the
species stipoides. It is liowever easy to place in the tribe of the Stipeae, because
the lemma is coriaceous, but we cannot include it into the genus Stipa, because

\') Stapp in Flora Capensis by Thiselton-Dyer, Vol. VII. p. 6S8. Sporobolus suMilis. Hero the
presence of a bristle-like continuation of the rhachilla is unique in tlie genus
=) Nees, Fl Afric. austral. (1841) p. 186. Specimen in the Berlin Herb

there is no trace of articulation between the lemma and the column of awns. There-
fore we are obliged to place it among the Aristidas as did Domin, who called this
plant Aristida Streptachne and who accepted R. Brown\'s genus as a section of
Aristida where the lateral awns are suppressed or wanting. If in an Aristida
belonging to the section Arthratherum — a section having an articulation between
the valve and the trifid awn-stipe — the lateral awns disappear, it is technically
impossible to distinguish such an Aristida from a Stipa. It may be that some well-
known »S^ipa-species are already such mutated /Imeldas If in the Australian ^ns^irfa
utilis, a species with distinct but thin lateral awns, those lateral awns disappear,
we have (as to the spikelets) before us the Streptachne stipoides of R. Brown. Brom
a theoretical point of view we must be consequent and unite the genera Stipa
and Aristida, for practical reasons it is however better to accept them as two
different genera.

In this work the tribe of the Stipeae, is formed by 8 genera with the following
diagnosis: The flowers with but one floret, rhachilla not produced beyond the
floret, fertile valve (lemma) hardened when mature and tightly enveloping the
caryopsis, nerves of the valve anastomosing or closely approaching at the top, awns
always terminal or from a slightly bilobed apex, rarely wanting.

II. Lemma always awned, laterally compressed or quite terete, sometimes quite
smooth, commonly striate, more or less rough or punctulate under a
lens, sometimes papillose or tuberculate.

■ A. Spikelets solitary on long peduncles, lemma produced into a short point,
no articulation between lemma and awn. Glumes very obtuse and

B. Spikelets never in 1-tlowered inflorescences, always in open or contracted
many-flowered panicfes, lemma always produced into a long awn
or with three awns at the summit, articulated with the body of
the lemma or not.

a. Awns eccentrically attached, the lemma mostly asymmetiical
epiblast very large, endosperm very small.

1. Palea very thin, short, membranaceous, nerveless, not keeled , .
.................. NASSELLA.

b. Awns not eccentrically attached, the lemma symmetrical or nearly
so, epiblast small, endosperm large.

aaa. Lemma narrowly linear, long and slender, awn bent,
twisted below, callus long and sharp-pointed ....
..................STIPA.

bbb. Lemma not narrowly linear, elliptic or very broad, plump,
awn falling off at maturity, very deciduous, not twisted
but somewhat bent, callus short or very obtuse or
nearly wanting, never acute and pointed.

BB. Lemma distinctly bilobed at the apex, the
straight awn rather firm, from the sinus .
............TIMOUIIIA.

bb. Awn tri fid or tripartite, lateral divisions sometimes short, the
awn articulated with the lemma or not, rarely the awn
simple but in that case never articulated with the valve. .
...................ARISTIDA.

As to the special characters of the family of the grasses I have little to observe,
a full description of the genus Aristida is given in another chapter of this w^ork.
Besides typical grasses there occur in our genus very characteristic sulfrutescent
species, these are mostly observed in the African deserts. Different of these desert-
species have very long roots which are covered with a tomentose tissue as a tunic,
mostly the surface of this tunic is covered with sand.

I have treated the most characteristic morphological characters which are very
valuable to recognize different species, in a special chapter and I will only discuss
here the structure of the spikelets. Grasses generally have a normal position of

the glumes, the lower one or outer glume is less developed and much shorter or
about as long as the better-developed upper or inner one. In our genus however
we find that there are numerous species with a so-called „inverse position\'\', the
lower glume is in that case better developed, more-nerved and much longer than
the upper one, this phenomenon is however not a. generic character of Aristida,
it occui\'s also in other genera f i. in the genus Stipa. I have used this character
to distinguish some allied species, few botanists have given attention to this inverse
position, which is a very useful guide.

Other morphological characters I will discuss here are found in the spikelets and
especially in the valve or palea inferior, the so-called lemma of the agrostologists.
This lemma has in our genus always a prolongation upwards, we call awn or arista,
or a very long, twisted, sterile part, we call column or column of awns. I must
observe here that morphologically spoken, we have two very different kinds of awns.
Palisot de Beauvois already called attention to the diiferent awns and it was
Duval Jouve who studied this question intensively. Let us take a spikelet of an
Aristida belonging to the section Arthratherum, here the lemma is produced upwards
into a strongly twisted, very firm sterile part, we call „columnquot; and which passes
into three „awnsquot;, in this case the prolongation or „columnquot; is in reality the
«awnquot; and what we commonly call „awnsquot; are the „setaequot;. In the development
of the lemma of an Arthrathenm-^\\)QCgt;\\e^, we see that the 3 awns are visible at
the beginning only as 3 separate points, which are supported by a small wart, in
3quot;oung states, the lemmas and the 3 awns are often quite developed before there
is a visible column, gradually the wart becomes elongated without dividing itsself
and grows out to what we call the „column of the awnquot;, bearing at the summit
3 „awnsquot; we must call „setaequot;; this column has quite as in the genus Sfrpathree
fibro-vascular bundles. The evolution of the awn in the Arthratherum-growi^ shows
clearly that the awn is not a prolongation of the midnerve, but that the setae are
prolongations of the midnerve. We therefore must speak of an „arista complétaquot;,
formed by a lower part. or column and an upper part or seta. French botanists
called the column: arête or arista and the seta they named soie. The dorsal awn
of our common Avena fatiia is thus an arista compléta, consisting of a twisted
column and a not twisted upper part we call subula. The awn of a species of
Bromus is thus not an awn but a subula only, because there is no column and the
history of the development shows that a wart which produces the column is absent,
such an awn we call „arista incompletaquot;. The 3 awns of ^r^/irai/ierMW form together
with the column the arista compléta of this section.

Duval Jouve compared the column with the petiole of the blades, the presence
or absence of a petiole, although important to recognize species, is not to use as
a generic character and in our genus Aristida we cannot separate as genera the
Aristidas with complete or incomplete awns. In all the sections of our genus there
occur species with complete awns.

Another interesting question is the development of the callus, this organ is very

important to recognize different allied species and therefore studied here more in
detail. The flowering glume or lemma extends a little downwards at the point of
insertion on the axis of the spikelet, this portion is composed of the true callus,
which is commonly hairy, and a naked coriaceous prolongation. The callus is not
a part of the lemma or an appendage to the base of the flowering glume, but it is
only a part of the rhachilla or axis of the spikelet, mostly the upper or the principal
part, which breaks off above the persistent empty glumes. This callus and its prolon-
gation have in the different species a quite different shape, a shape which depends
on the distance between the true base of the lemma and the point of insertion of
the empty glumes; this distance is very variable, we have thus hi our genus all
transitions between very long and very short forms of the callus. In Aristida
hygromeirica of Australia, the callus is about 5 mm. long and very pungent, other
species as A. oligospira and A. tincta have a very short callus, which is sometimes
only a fraction of a millimeter. The interval between lemma and insertion of the
glumes is very constant in the different species and the naked firm prolongation
is so constant in shape, that it is of great importance to recognize different species.
Hitherto little attention was given to this character and it is very curious that
there was not a single author who has seen, what I have called, the „bifid callusquot;,
that is thus in reality the bifid prolongation of the callus. This shape of the callus
and its prolongation depends not only on the length of the interval, but also on
its tendency of development. If the interval is long, the long callus has a conical
and sharp-pointed prolongation, if the interval is short and the tendency of develop-
ment very pronounced, there are different possibihties; if there is no place enough
for the prolongation, the point is forced away laterally and we have the oblique
laterally developed callus of the Aristida megapotamica, but it occurs, that the naked
point is developed on both sides of the rhachilla and in that case we have the
bifid prolongation found in Aristida riparia, A. hystricula and in nearly all the
members of the African group of the „diffusaequot;, (Aristida diffusa, A. vestita, A. stip)oides
etc.), if the tendency of growth is in accordance with the length of the interval,
tlie callus may be subobtuse or very obtuse or even rectangularly truncate.

Because the shape of the callus and its prolongation is proved to be of great
importance as a constant character of each species, I have discussed this question
here more in detail.

The callus is at the same time of great biological importance; together with the
whole lemma and the twisted column and awns, it serves to fasten it to other
objects, the callus makes the penetration easy and the stifl shorter or longer hairs
of the upper part of the callus, pointing upwards, make it difficult to draw out a
lemma that has penetrated the soil or the clothes of men; the strong, very hygroscopic
column, twisted like a rope, often acts as a motor, the coils unroll when moistened
and when drying , up they return to their former condition. By this rotation and
nutation, the lemma with the fruit bores deeply into the soil. The fruits are often
so sharp that they penetrate into the skin of animals or men and cause dangerous

inüamations or even the death, the lemmas of the smaller species become often
very troublesome to passengers.

Some species have very long awns, so the North American Aristida longiseta,
but especially the South American Aristida pallens, where they are sometimes
20 cm. long, these long awns are divergent at maturity and are a distinct aid in
transportation by the wind, in A. pallens the long panicles are drooping and the
lemmas with the awns form a parachute and are driven through the air. The long
feathery awns of many African species act in the same way.

Cleistogamic species are observed in our genus. Here, the self-fertilisation is
finished at or before the moment that the panicles protrude above the sheaths. In
such species there is but one stamen, which is 0, 3—0, 5 mm. long and the lodicules
are absent. Aristida longespica, A. oliganlJia and A. basiramea belong to these
cleistogamic species, the latter is very characteristic, at the very base of the culm
there are 1—2 leaves with small panicles hidden by the sheaths.

There is an extensive literature on the anatomical characters of the grasses; as
to those of the genus Aristida, I have to discuss here only a question which is
important for our genus, because it gives an idea of the relationship of the sections
with other genera.

The nerves of the blades, the fibro-vascular bundles, have a parenchyma-sheath
and inside this sheath we find the leptome and hadrome of the structure and
disposition, characteristic of the grasses in general This parenchyma-sheath consists
of thin-walled cells filled with chlorophyll. In a transverse section of the blade of
an Aristida 0Ï the section Ghaetaria f. i. the North American Aristida purpurea, the
thin-walled parenchyma-sheath is of coarse present, but this sheath encloses
another sheath of larger cells with slightly thickened walls also filled with chlorophyll.
We have thus here what is called a „double parenchyma-sheathquot;; it is
observed in the species of the section Ghaetaria, in Aristida funiculata oïi\\\\Q^ec,i\\on
Arthratherum, in Aristida mutahilis of the section Fseudarthratherum, in Aristida
dichotoma and other representatives of the genus Curtopogon of Beauvois and the
same structure occurs in the species of Hitchcock\'s Uniseta, Aristida ternipes,
A. divergens and A. Schiedeana, which belong to the section Streptachne. This section
is anatomically thus inseparable from Ghaetaria and we know that many
intermediary forms occur between the two sections.

It is however very striking that this double parenchyma-sheath is not observed
in the two sections Stipagrostis and Sc/ifstoc/ine; Duval-Jouve who studied the North
African Aristida pungens, a member of the Stipagrostis-gvouip, found only the normal
case, one parenchyma-sheath, filled with chlorophyll and many other species of
this section possess only one parenchyma-sheath around the mestome-bundles,
these species of the Stipagrostis-grouT^ are thus anatomically quite distinct from

the others mentioned above. This structure is f. i. observed in the allied species
Aristida pennata, in Aristida plumosa and its allieds, in Aristida acutiflora and
A. hrachyathera and also in the chief representative of the section Schistachne, the
Aristida ciliata. In the genus Stipa, so far as studied, a double parenchyma-sheath
was never observed and anatomically the sections Stipagrostis and Schistachne are
thus more allied to the genus Stipa\\ if we take the anatomical characters as a
basis for classification, the genera Aristida and Stipa must be sharply separated
but in that case we must unite Stipagrostis and Schistachne with Stipa and the
latter genus is than only a i-awned Stipagrostis or Stipagrostis a 3-awned Stipa.
All the other genera of the Stipeae, so far as studied, are readily distinguished
from the genus Aristida, by their having only one parenchyma-sheath and in the
tribe of the Stipeae, the genus Aristida (if we exclude the sections mentioned above)
is tluis a well-marked one.

We must observe here that the mestume-sheath, described by Schwrndener, a
sheath that occurs inside the ordinaiy parenchyma-sheath, is not to confound with
tlie inner parenchyma-sheath, this mestome-sheath of Schwendener is prominently
thick-walled and easy to distinguish from the surrounding parenchyma-sheath by
treating the transverse section with concentrated sulphuric acid. The mestome-sheath
of Schwendener does not occur in the sections Stipagrostis and Schistachne, but it
is present in the genus Stipa and in all the other genera of the Stipeae and most
of the Agrostideae. The absence of this mestome-sheath in Stipagrostis send Schistac?ine
may possibly indicate a closer affinity to the other sections of the genus Aristida,
the single parenchyma-sheath indicates at the same time a closer relation to the
genus Stipa. It would be consequent to remove the sections Stipagrostis and Schistachne
from Aristida proper, their morphological characters are also very distinct, but it
is to my opinion not allowed to divide ylris^/da on account of peculiarities in structure
of the blades. We know that Rikli divides the genus Cyperus, on account of the
presence or absence of the inner green parenchyma-sheath, into Chloro- and Eu-
Cyperus; the morphological characters are however in this case too much neglected.
In Aristida the species of the section Stipagrostis are merely plumose members of
the section Arthratherum. if there was f.i. an Aristida pungens with naked awns,
we had to place it without difficulty in the section Arthratherum. We must moreover
call attention to the fact that Aristida secalina is probably a naked-awned Stipa-
grostis, while Aristida sericans on the other hand is a feathery-awned Chaetaria,
because there is no articulation between lemma and column and for this reason
excluded by me from the section Stipagrostis.

As is already indicated in my work, it would be advisable to make in each section
of the genus smaller groups, especially in those sections where there are so many
species as in the section Chaetaria; only the botanists who have intensively studied

a number of species of a group can recognize it, mostly by indefinite characters
of habit and growth, I have therefore used as much as possible only the morpho-
logical characters. Species with quite the same habit are often quite diiferent in
the spikelet-characters, characters we find only after a very careful examination
of the different parts of the lemmas and glumes, on the other hand there are
different species with about the same spikelet-characters which are totally different
in the vegetative parts. The South American species Aristida riparia and Aristida
Trinii have quite the same habit and agree in the vegetative characters, to distinguish
them, we must open a spikelet and examine the callus and its prolongation, to
recognize these two species at once. To distinguish the species I have used the
characters already found in the literature, but I was so fortunate to find other
very valuable characters, some of them never observed in our genus ore overlooked.
One of the most valuable characters is the position of the glumes. The normal
position is commonly found in grasses, here, the lower glume is shorter than the
upper one. I have named the position „inversequot;, when the lower glume is prominently
longer than the upper one and moreover always is better developed. In the section
Arthratherum, the whole group of the Juniculataequot; is to recognize by the inverse
position of the glumes (A. funiculata, A. Boyleana, A. polyclados). In A. Stocksii this
character is extraordinarily striking. The South American A. mendocina and A. inversa
bave this character and also the South American group of the „circinalesquot; (A. circinalis,
A. Spegazzinii), diilerent African and Australian species are easy to recognize by
this character. In some species with inverse position of the glumes the spikelets
are dimorphous, fi. in Aristida jorullensis, here the shorter awned lateral spikelets
are smaller and the glumes are subequal. Other important characters are found in
the nervation of the glumes. In the group of the Amei\'ican Jongisetaequot;, the South
American Aristida vemistula is to recognize from the North American A. longiseta,
which has quite the same habit, by the characteristic anastomosing nerves of the
lower glume, in A. longiseta the lower glume is but 1-nerved. The shape of the
callus and its prolongation give us other very valuable characters for the discri-
mination of the species. So we recognize Aristida megapotamica with its oblique
callus, A. riparia, with the bifid prolongation of the callus, A. oliyospira with the
very obtuse callus and A. Trinii and A. Ekmaniana hj the very acute one. Aristida
gyrans we recognize from the allied A. réfracta and A. Rosei by the length of the
callus. A quite naked or only sparingly pubescent callus is only observed in the
group of the „pungentesquot; of the section Stipagrostis. Spikelets of Aristidas attacked
by a black fungus have mostly a naked callus.

Another important character is the presence or absence of a column to the lemma
or a beak at the summit. It is not always easy to recognize the sterile upper part
of a lemma from the column or beak. A column or beak is always filled, the
sterile prolongation of a lemma is a hollow cone and in transverse section a ring.

A very important character is observed at maturity in different species, in most
of the species of our genus the lemmas are tubulous with overlapping margins.

There are however dUIerent species where the margins of the lemma are inrolled
at maturity, here we find thus at the ventral side a very prominent furrow from
the base to the branching point of the awns. This character is never observed by
other botanists or totally overlooked, but it is of great importance and makes it
easy to distinct some diflicult species. We find this character in the group of the
South American „circinalesquot; (A. circinalis, A. Spegazzinii, A. acuminata, A. leptochaeta);
in the rare Brazilian Aristida siibaequans and in A. tarapotana, but also in species
of the Old World. Here it is observed in the African A. rhiniochloa and its allied
species. In the Australian species it serves to recognize the Aristida calycina from
Aristida ramosa and is observed there in different other species such -as A. praealta,
A. armata and A. inaequiglumis, the latter ones are moreover very curious by the
spiny hairs, placed in the furrow of the lemma. Much attention must also be
given to the summit of the glumes in our genus. It is however very disagreeable
that in herbarium-specimens the glumes are often damaged and the old descriptions
are thus often difficult to controll. In the types of many species the points of
the glumes are not rarely broken off, although the authentic descriptions mention
the acute or awned glumes, in some species the long awns of the glumes are very
fragile and a careful study of numerous spikelets must give us the right idea of
the shape of the summit of the glumes, the awns of the lemmas are not rarely
damaged and we must study the tips under a strong lens if we will controll
their length.

Most of the species of our genus are perennial, if the plants are collected with
sufficient basal parts, it is commonly not difficult to see if the species is annual
or perennial, there are also species where the basal parts are not or very insuffi-
ciently known. Annual are the A. adscensionis, the African A. mutabilis and the
allied species A. yneccana, A. Cassanellii and A. astroclada, further the species of
the „fiiniculataequot; (A. funiculata, A.polyclados, A. Royleana, A. Stocksii) and A. hystricula,
the elegant desert-species A. subacaulis is an annual and also the South African
A. curvata. In North America the following species are annual: Aristida tuberculosa,
A. desmantha, A. intermedia, A. longespica, A. oligantha, A. basiramea and A. dichotoma,
in South America we find the A. capillacea and the A. setifolia. In the Old World
we find in Africa the section Pseudochaetaria with its 3 annual species: A. hordeacea,
A. Kunthiana and A. Cardosoi, annual are further A. Cumingiana and Aristida
hirtigluma of the section Stipagrostis. Some perennial species blossom already in
the first year of their development and are not easy to recognize at the beginning
of the flowering-time, they afterwards produce sterile innovations and are better
to recognize as perennial. Such a species is f. i. Aristida coerulescens.

The internodes furnish us other important characters, they are glabrous or
scabrous, pubescent in some species or very characteristically lanate or woolly.
The wool is often fugacious and easy to rub off, old herbarium-species have lost
this tomentum, in this case we find it bow-ever always on those parts of the culms
which are concealed by the leaf-sheaths. The internodes are different in length,

sometimes alternately long and short and the species has than a very characteristic
habit {Aristida geminifolia, A. macilenta, A curtifolia), sometimes the culm is nodeless
or the basal node is only present (A. enodis, A. recta, A. venustula, A. teretifolia).
The leaf-sheaths are sometimes very scabrous (A. hirta), some species have lanate
or woolly sheaths {Aristida lanosa, A. Dewildemani, A. Scribneriana, Aristidaplumosa),
sometimes the sheaths are coarsely hairy and the hairs tubercle-based {Aristida
rufescens).

The ligule is in our genus very uniform and of little value, the auricles however
are more important, sometimes beautifully bearded with very long hairs. Very
striking and valuable is the prominent villous or pubescent line across the collar,
a line which is sometimes developed as a so-called ,,ligula externa\'\'Fnesw,
A. laevis, A. Wrightii, A. Eggersii).

In the keys I have used the characters of the auricles very sparingly, although
they are given in nearly all my descriptions of the species. The hairs are often
deciduous in old specimens and the character of the hairy auricles ought to be
studied with living or fresh material. The blades of the Aristidas have not rarely
much thickened margins with bands of sclerenchyma {Aristida marginalis, A. laxa,
many Mexican species), sometimes the blades are quite Hat and rather thin or
slightly folded only {A. Jiordeacea). Desert-species have not rarely very firm and
pungent almost junciform blades {A.pungens, A. vulnerans, A. scoparia and A. sabiilicola),
some species have very curled or strap-shaped blades {A. nemorivaga, A. circinalis,
different Mexican species).

The panicles are very different in form and outline, the axils sometimes ciliate
or bearded or with a Hake of wool. This character is important to recognize Aristida
vulnerans immediately from Aristida scoparia and pungens. Aristida lanosa has a
very prominent tuft of wool in the axils, other species as Aristida adoensis have
only a pencil of hairs. The shape of the panicle is in many species very constant,
but in others (A. adscensionis) it is exceedingly variable.

It was of course impossible to give in this work all the variations I observed ; if
we have f. i. the subspecies bromoides oi Aristida adscensionis, ^ subspecies very
characteristic for the liigh Andes (Ecuador, Peru and Bolivia) on account of the
acuminately awned not bifid tips of the glumes, the material of this subspecies,
placed together, proves to be very multiform, there are dwarf plants or very long
ones, some specimens have a very dense, spike-like panicle, other ones are ratlieV
few-tlowered with looser panicles, there are simple and much-branched forms, shorter
and longer leaves occur, etc.. It may be that some of the forms are induced by
diversity in environment but certainly not all these forms. The study of those minor
variations can only be carried out in field work by competent agrostologists.

Dillerent plants of a certain group we recognize often by a single character, but
usually such plants\' differ by several or many characters and the more- frequent
combinations in nature catch our attention. Different existing combinations are often
neglected or overlooked or accepted as „intermediatesquot;. If we study a very variable

group of plants it often happens that a considerable number of the possible com-
binations is wanting. This is not because they do not exist, but mostly, such combi-
nations are not yet found. In South America we have a small group of Aristidas
with inverse position of the glumes and erect awns, all the species of this group
have at the same time the very curious character of the deeply furrowed lemma.
The combination of the deeply furrowed lemma with the normal position of the
glumes is possible and certainly to (ind. and a plant with such characters belongs
to what I call a „theoj-etical speciesquot;, I have assiduously looked for such species
in all the numerous collections I had at my disposal and I have found expected
constant combinations here and there in the diffei-ent collections, each new explo-
ration of little-kncwn regions brings us such new combinations. Of course, the minor
variations are not so striking and easily overlooked by the collectors. Parallel variations
described by the eminent French botanist Duval-Jouve are more and more accepted, if
we have discovered all the various combinations, these will fit into an artificial prearran-
ged system, as is suggested by Vavilov who has based his method upon what he calls
the law of homologous series in variation. It is evident that these parallel combina-
tions are proposed within the range of a species, but in working out a monograph
of a genus with numerous species, distributed all ovej- the world, we can use this
suggestion of Vavilov with great profit. In the genus Aristida there are certainly
more unknown species and I am convinced that we find them when we can study
more material, it is not only a necessity but also a duty of all the institutes of tlie
world, to bring together the most extensive material of herbarium-specimens before
it is too late and I will finish this chapter with the motto: Multum et mult a.

We have already seen that it is not so very easy to give a sufficient arrangement
of the many species of our genus; we find apart from the anatomical characters
but few data which are apt for an incorporation. Since the time that agrostologists
called attention to the articulation in the family of the gi-asses, this character has
often be used: the articulation of the rhachis of a panicle in our spontaneous
species of Triticum and Hordeum, tlie articulation of the rhachilla of the spikelets
in Avena and the articulation of the pedicels just below the glumes in many grasses.

It is therefore not surprising, that the articulation, found in our genus at the
summit of the lemma or just below the branching-point of the awns, is accepted
by many authors as a basis to make large groups or sections. Especially those
species with all the awns or at least the central one feathery, were united together
in one section if there was an articulation between the column and the lemma.
This section was first described by Nees as a genus under the name of
and based upon the Stipagrostis capensis which is the same as Aristida obtusa. Here
there is a prominent articulation at the summit of the lemma, but Nees gave more
weight to the character that the column is placed between the obtuse lobes of the

lemma, it is curious that Nees placed other species of this section with quite the
same character of the bilobulate apex of the lemma in the section A-VthTcitJiBTUfn
of our genus. Because the type of the genus Stipagrostis is the species we now
name Aristida obtusa, for reasons of priority, I have united under the section
Stipagrostis all those species with the combination of the articulation at the summit
of the lemma and at the same time with at least the central awn more or less feathery.

The exact place of the articulation we accepted as very important, and as a basis
for our sections. We had thej-efore to exclude those species of Stipagrostis where
the articulation is not at the summit of the lemma but where the lemma is
articulated at or above the middle. This character was indicated by Figari and
Denotaris for their genus Schistachne with the type Aristida ciliata, which has a
great affinity with the section Stipagrostis, we find moreover a hybrid between
Aristida ciliata and an important member of the section Stipagrostis, the Aristida capensis.

If there is an Aristida with plumose awns but the articulation is absent, the
species is taken from the section Stipagrostis, and consequently placed under the
Ghaetarias. Aristida secalina is anomalous in the section Schistachne .but is
insufficiently known.

The Aristidas without plumose awns are to divide into two large groups, one
without and one with a prominent articulation. The first group is the most
difficult one, it contains nearly 200 species, among them w^e find a small group
where the lateral awns are reduced or wanting, or if somewhat developed, they
are much thinner than the central one. This is the section Streptachne, it is not
very important and merely consists of reduced Ghaetarias, it is connected with
Ghaetaria by many intermediary forms. Most of the species of this section are rather
characteristic and readily recognized and I have therefore maintained Streptachne
as a section of Aristida in this work. To avoid mistakes in the determination, I
have mentioned some species in the keys under both sections Ghaetaria and Streptachne.
The section Ghaetaria in the proper sense contains thus all the unarticulated
Aristidas with well-developed lateral awns. This section is very heterogeneous and
it is difficult to divide this section into natural groups. We know that Doell
has proposed two groups, characterized by the absence or presence of a column
and although there are names for those groups in the literature, 1 have not taken
up them; between the species with a very long column and those where the column
is developed only as a beak or rostrum, there are so many intermediates tliat a
limitation of such groups is scarcely to give as a system, although we can use the
length of the column for our keys to the species.

Here we can sharply distinguish the species without a column, these species are
simply organized, the lemma passes immediately into the 3 awns with an articulation
at the summit of the valve. They belong to a section I have named Pseudochaetaria,
a section with only 3 annual African species. The remaining articulated Aristidas
have always a more or less developed, sometinies straight, mostly twisted column

or beak. As to the place of the articulation there are two possibilities, the
articulation is placed at the summit of the lemma or at the summit of the column
just below the branching point of the awns. The two groups are very characteristic,
the first group was already recognized and described as the genus Arthratherum
by Beauvois, the second group received a name in modern time by Chiovenua as
Pseudarthratherum, the old botanists however had not overlooked this group but not
given so much weight to this character. In the section Arthratherum we have a
very natural group of about 40 species, all have a very stiff column and a very
prominent articulation, the column falls off quite spontaneously at maturity. The
other section where the column is articulated just below the branching point of
the 3 awns is also very natural, the species of this section are not so numerous,
about 20 are known, they have always a much thinner, more elegant column, the
awns are not deciduous, the articulation is mostly visible as a nodule below the
awns, the latter break off at maturity only when we force them to diverge. A
nodule below the branching point of the awns is however no indication of the
presence of an articulation, there must be at the same time a special tissue, there
are among the Ghaetarias such species where we find an indication of such a
nodule, although a true articulation is not present at all.

We know nothing about the real value of systematic characters in general and
their value in a definite genus does not give us the right to applicate these
characters as value in other genera. In some genera the characters of the
inflorescence sharply differentiate the species, in our genus Aristida the shape and
characters of the panicle are of no value for subgenera or sections Although an
immense material has been studied, this work is but an attem|)t for the classification
of such a complex genus as Aristida. Characters, suited for the formation of sections,
I have only found in the structure of the spikelets and especially in the lemmas
and the articulation of the awns. 1 have accepted in this work 7 sections, one of
them is not very natural but maintained for practical reasons only.

f. Geographical characteristic of the sections and species of the genus Aristida.

The species of Aristida ai-e widely distributed over the warm and temperate
regions of the w^orld, but the area shows many interruptions. As to the different
sections of our genus we note that they are very irregularly distributed. Beginning
with the sections Stipagrostis and Schistachne it is very striking that they ai-e
limited to the Old World and especially to its westei-n part. The section Sc/ristoc/me
has about 8 species, 7 of them are represented in South West Africa {A. Dinteri,
A. Hochstetteriana, A. prodigiosa, A. proxima, A. Schaeferi, A. namaquensis) where
also the anomalous A. secalina is found, which seems to be allied to A. Hochstetteriana.
All the species are desert-plants with very distinct characters and generally rather
uniform. The common Aristida ciliata occurs not only in South Africa but is very
common in the deserts of North Africa, from the Sahara to Nubia, Lybia and

Ai-abia, and occurs also on the Sinai and in l^ersia. In its northern range this
species is not so very variable, but in South West Africa a greater diversity is
observed. The 38 species of the section S/fparyTosa\'s have about the same distribution,
most of them occur in South Africa, the supposed origin of the section. A common
member of the section is the uniform Aristida obtusa, found also in tlie northern
area, it reaches Arabia but is wanting in tropical Africa. North Africa has a
series of characteristic species, some of them are endemic f. i. Aristida oranensis
in Tunis, A. brachyaihna in the Algerian Sahara, A. sahelica in Algeria, A. Zittelii
in Lybia, A. vulnerans in Egypt. Other species have a somewhat wider range
f. i. Aristida acutiflora from Nubia and Egypt, A. hrachypoda with the same range,
A. scoparia from Egypt to Syria. Aristida sokotrana is endemic on the islands of Sokotra.
Very curious is the distribution of two much allied species, the Aristida Raddiana,
wliich is found in northern Egypt to Sinai and South Persia, and the Aristida
which is limited to Somaliland and S. W. Arabia (Aden). Widely distributed
species are more variable and some of them are very rich in varieties. Aristida
papposa is found from the Cape Verd Islands and the Senegal to Nubia and Abyssinia,
Aristida Mrtigluma occurs from Egypt to the Sinai, south to Eritrea and Arabia,
east to British India, but it occurs also in South West Africa. Aristida pungens is
a Sahara-species, distributed from Tunis and Algeria to Nubia and Egypt, with a
subspecies in South West Africa. Aristida pennata ranges from the Caspian desert
to Transkaspia, Turkestan and East Persia. Aristida lanata is found from Egypt to
Sinai and Syria, Aristida arachnoidea in the Transkaspian desert and Aristida
Griffithii in Afghanistan. The very variable Aristida plumosa has a horizontal
distribution from the Algerian Sahara to Egypt, Nubia and Palestine, east to Arabia,
Persia. Turkestan and West Tibet, noHh to Armenia. A beautiful species is the
A. pogonoptila, only observed from Beluchistan to British India.

From the following remaining \'17 species there is none observed in North Africa
above tlie equator and they are limited to the western part of South Africa. In
South West Alrica. Damaraland, Little and Great Namaqualand and the western
part of the Cape Colony we find: Aristida geminifoUa, A. fastigiata, A. Dregeana,
A. lutescens, A. Marlothii, A brevifolia, A. damarensis, A. sabulicola, A. garubensis,
A. gonatostachys, A. lanipes, A. Herm-anni, A, subacaulis, A. gracilior and A. uniplumis,
thequot; latter has a wider range and goes west to Transvaal and south to the Cape
Colony. Angola has an endemic species, the A. tenuirostris. One species the ^m^ida
capensis is very variable and occurs from the Coast Region of South Africa to Little

Namaqualand. From the geographical distribution of both sections, treated here, one

might conclude that we have here a distinct genus before us, a hypothesis we cannot
wholly reject if we consider the morphological and anatomical characters of these
sections. The section Pseuclochaetaria contains but 3 species. Aristida Kunthiana with
the liabit of A. mulabilis is only observed in Senegambia, a second species, Aristida
Cardosoi, with the habit of Aristida adscensionis is endemic on the Cape Verd Islands,
tlie third species,. Aristida hordeacea is more widely distributed and found from

Ihe ectwn Arl/gt;rat/gt;e.um with its 40 species has but 5 representatives in North Am rica

charactensfc gronp of this section with a bifid prolongation of the callus (i AvZ

group, thesl,poilt;les, is found i„ North Africa from the Lnega to Kordofan and

horizontal dispersion; the most common species of this group is A funicnlata and

one sp cies of thjs section, the J. ambongensie. The Australian contineirt has at least

tZTZwquot;^ -e»«™,. It is curious that the islands of thepkcificand re
Malayan Archipelago do not contain a single species of this section. One species
(.A. tenumtuhsa) is found on the Philippine Islands.

Let us turn now to the section Pseudarlhratherum, where we have another verv
curious geogi-aphical distribution. About 20 species of his section are know none
0 them IS found in North America, and South America has but 2 species in Braquot;il

established by the discovery of intermediates of probably hybrid origin The Gala-
pagos Islands, famous for their great many endemic spLes, have nTie^ thafs

^i\'str lntn I, P 1 1 Tquot;quot;^ section are African, One of them with an eastern

disti bution to Central Asia. In North Africa we lind Aristida tunetana in Tunis
J. elytropl,oroid^ and ^, astroclada in Eritrea,nbsp;in Nigeria. Aristtta

meccana has a strange distribution, it is observed in South West Arabia (Aden)
Mecca and the Smai, but also in the so-called Arabian desert. The occurence on
the Island^ Gran Oanaria (Mas Palomas) may be explained by introduction in recent
time from the Orient.nbsp;is distributed from the Senegal to Abyssinia

east to British India, the aUied A. Cassanellii from Eritrea to Abyssinia. In South
Africa we find diiferent species of our section, A. congesta, A. barbicollis, A. Rangei,
A. Lomnielii, A. Pilgeri, A. alopecuroides, the A. longicauda is only known from
Mozambique.

The section Strcptachne is, as already observed by me, not very natural, the New
World species are probably descendants of Ghaetaria species. In the New World we
find the annual^, jorullensis from Mexico to Panama, Aristida divergensfrom Texas
to Nicaragua, A. floridana in snuthern Florida, A. gtminiflora in Mexico \'a.x\\AA.Pur-
pusiana in California. A rather common species is A. ternipes, it ranges from New
Mexico to Columbia but occurs also on the Bahamas and Cuba. Two species
A. ScJnedeana and A. Orcuttiana are often confused, the latter is the northern species
that ranges from Texas to New Mexico and Arizona, the former is the southern
species, found from Mexico to Ecuador. Hybrids occur between them and also
between Aristida Schiedeana and A. laxa of the CAaeto.na-section. The Old World-
species of the section Streptachne form a more natural group, their distribution is
very curious, one species (A. abnormis) is found from Eritrea to Somaliland and
east to Persia, an allied species {A. redacta) is only found in British India. The
Australian continent has 3 remarkable species in Queensland, S/rep^ac/we,
and A. utilis, the latter is also observed in East New Guinea.

We now come to the true Aristidas, forming the section Ghaetaria, with about
200 species, distributed in the New and in the Old World. It is noteworthy that
there is but one cosmopolitan species among them. In the New World the species
are found from British Columbia and Canada all over the United States and Mexico
to Panama and in South America to the Rio Negro in Argentina. The species are
found on the sandy plains and prairies, also on the mountain slopes of Western
America or on the moist pine-barrens of Florida, in South America on the pampas
and savannas or high plateaus and on the mountains of the high Andes. In the
Old World we find our genus but sparingly represented in South West Europe.
In the Orient better represented from Syria and Palestine to Arabia and Persia,
east to Tibet, Cochinchina, southern China and Formosa, south to Ceylon and the
Philippines. The genus is wanting in Siberia and Japan and in the Malaj^an Archipelago.

The Australian continent has many species, a few species are endemic in New
Caledonia; Tasmania and New-Zealand have no representatives. In Africa a great
many s[)ecies are found on both sides of the equator. Madagascar and the adjacent
islands have their own species, some species are also found on the islands of the West
Coast of Africa: Madeira, the Canaries, Cape Verd Islands, St. Helena and Ascension.

Let us consider now the distribution of the different species of our genOs and
begin with North America. Here we find a number of characteristic annuals:
A. dicholoma, A. Gurtisdi, A. longespica, A. basiramea, A. intermedia, A. oligantha
and A. ramosissiyna. Another group in America is tliat of the „purpureae\'\' with
A. longiseta, A. Fendleriana, A. Wrightii, A. purpurea, A. rariflora, A. Roemeriana
and A, glauca, species from the plains or rocky hills; other species are found in

the Jow pine barrens and flatwoods: A. condensata, A. tenuispica, A. Mohrii, A. sim-
phaflora A pa ustris, or in dry sandy soil, as patula, A. spiciformis, A. gyrans,
A virgata A. lanosa, A. purpurascens. The southern States of America have a series
ot characteristic species, many of theui also found in Mexico (A. barhata, A. divaricata
A hamulosa, A. gentiUs, imbricata, A. ParisMi, A. arizonica). Chiefly Mexican are
A. Scnbnenana, A. curvifolia, A. Lagascae, A. laxa, A.Jacguimana,A. mexicana, A. oriza-
bensts, A Liehynanrd, A. Hitchcocldana^A. a^i^r^ssa. Central America has moreover some
species also found in South America a. megapotamica, A. sorzogonensis, A, recurvata,
A. Uncta and vl. capillacea). The West Indian Islands have a series of endemic species
1\' \' wfnbsp;Porto Rico), A. Bosei (Haiti), A. Brittonorum (Lh^)]

A vilfifoha (Cnh^), A. neglecta (Cuba), A. Chaseae, A. portoricensis (Porto Rico
A. erecta {Cuba) A. cognata (Virgin and Windward Islands), ^^•aW.fana (Jamaica)

A. Aggersiz (Cuba), A. arubensls (Aruba and Curasao), A. Suringari (St Eustatius^\'
and A. curtifolia (Cuba).nbsp;^ V • J^-ubiaiius;

South America furnishes us a considerable number of new species, growino- on
the savannas and high plateaus and on the mountain slopes of the high Andes ud
to altitudes of 3500 meter. The North American group of the „p.r;,™quot; is repre-
sented by about o species venustula, A. subulata, A. trachyantha, A. Arechavaletae
and A. vexativa), allied to this group we have here that of the „pallerites^^ with a
series of beautiful species murina, A. pallens, A. valida, AJeretifolia, A. altissima
A. laems). Very characteristic for South America is the group of the „aVdna^.«quot;
with furrowed ventral side of the lemma (A. circinalis, A. acuminata, A. leptochaeta
A. succedanea, A. tarapotana, A. subaequans. A. Spegazzmii). The „divaricataequot; are
represented by A. Asplundii (Bolivia) and A. Parodii (Argentina) and two outlvino-
species in Brazil (A. flacdda and longifolia). Another very characteristic group
IS that of the „ripariaequot; with 7 species (A. chapadensis, A. macrantha A meqapo-
tamica, A. Mmaniana, A. Trinii, A. rip aria, A. oligospira), more or less allied to
this group are A. Neesiana, A. recurvata and A. macrophylla. knother group is formed
by A. Mandoniana (BoVivm), A. achalensis\'And A. decipiens in Argentina and A gibbosa
m Bmzil. The group of the Jincta.quot; is represented by A. torta, A. Uncta, A.?igida,
A. Fnesn and A marginalis, that of the „inversaequot; bynbsp;msndodna,

^nd A. Hackeli from Uruguay. All the species enumerated here are perennials there

Brazil A cap^llacea, widely distributed from Brazil to Guiana and Central America

The third anmial species is the common adscensionis. a cosmopolitan species with
numerous varieties in the Old World.nbsp;^P«cies witn

The section is represented in the Old World by many species, let us take the
African continen with the surrounding islands. Here we have the followino \' oup :
the Mpamtae , limited to South Western Africa, with A. bipartita, A. scabrivalis^

A. effiisa, A. Waiheliana, further the Junciformesquot;, all South or Tropical African
ones, with A. j unci for mis, A. denudata, A. macilenta, A. Welwitschii, A. nemorivaga,
A. canescens, A. Galpinii, A. huillensis, A. monticola. A very characteristic group is
that of the „rhiniochloaequot; with inverse position of the glumes, deeply furrowed
lemma and triquetrous awns {A. rhiniochloa, A. serrulata, A. andoniensis). Endemic
species are A. Burkei (Kalahari Region), A. somalensis (Somaliland), A. Sciurus
(Transvaal to Natal), A.Pennei(Eritrea), A. furfurosa(Uganda), A.leucophaea(Rhodesia),
A. chrysochlaena (Angola), A. Dewildemani (Belgian Congo), A. Vandcrysti {kngola to
Congo), iexi?\'fe(Nyasaland), and A. adoensis (Abyssinia to Uganda). Aristida recta
rano-es from the French Congo to South West Africa and east to Natal. Aristida sericans
from the Kalahari Region is an outlying species with plumose awns. Madagascar has
several endemic species {A. similis, A. multicaulis, A. Perrieri, A. chaetophylla and J..
rufescens, the latter is also found on the Comores and Nossi Be). A very curious annual
species (A. mauritiana) is found on Mauritius. The group of the „adscensiones\' has
besides A. adscensionis a subspecies guineensis in West Tropical Africa and two
other annual ones, the A. curvata, limited to South Africa and A. submucronata in
Tropical Africa. The annual A. adscensionis has a more northern range, it is very
variable and is found from the west coast to Abyssinia, as a whole the area is
strongly narrowed in latitudinal direction, extending east through Arabia and Persia
but underbroken by the mountain systems of Central Asia, it is oncemore found
in southern China. Another interesting species is the perennial A. coerulescens, a
species with two distinct areas, one is entirely western-Mediterranean, from the
Canaries to Morocco, Tunis and Algeria, an area also including the occurrence in
southern Spain and southern Italy. In this area the species is not so very variable.
The other area is eastern-Mediterranean. Aristida coerulescens is a mountain-species
and we find it thus in Syria, Arabia and a part of Asia Minor. Two species of
Africa have another very curious distribution, one of them is the A. Gumingiana
with an interrupted area. In Africa, it is found from the Senegal to Abyssinia. We
find it iri Asia from British India, Siam and Tonkin to the Philippines. The other
species is Aristida setacea, not observed on the African continent but only on the
Mascarene Islands (Mauritius and Bourbon). We find the same species also in

Besides the two species, mentioned here, there are in Asia some endemic species
as A. culionensis (Cochinchina to the Philippines), A. Balansae (Cochinchina),
A. annamensis (Annam), A. HysUix (British India), A. cyanantha (Afghanistan to
the Western Himalaya) and A. chinensis (Cochinchina to China and Formosa). The
annual A. depressa, a member of the adscensionis-gvoup is the vicarious species of
the A. adscensionis. Aristida adscensionis^ and A. depressa both occur in Asia but the
latter is limited to Central Asia (British India and Cochinchina),

The whole o-eoo-raphical area of the section Ghaetaria in Australia must be divided
in an eastern region, very rich in species and a western region where the Aristidas
of this section are very sparingly represented. New Caledonia has two endemic

spec,es, A püosa A. mvae-caledonim, both allied to the A. queemlmdiea the
t ^ quot;nbsp;The continent of Australia hasnbsp;^f

tïZ T I ^ characteristic group form the .calyoinaequot; with inrolled lemmas
and a furrowed ventral side, to this group belong: ArisUda calycina, A praeam
X prumosa A armata, A. eauroiées and ina^iuiglumis and also the lerall j
A ecMnata. A. mgrata and A. ierichomas. Aristida adscensionis is recorded byÏÏme
authors from Australia hut the specimens s„-nungt;ed belonged to qnitr rliffereTu
spec,es and .f n ,s met with, it must be regarded as adventitious.

^atura hybridization occurs between different species of onr genus in the olaces
where alhed species meet another and we mnst admit new spedes suZaes o
v mces by w^y of natural hybridization. Diiferent badly know,; .e^ fs of tl

wor d are ,„hab,ted by unknown species of our genus which ,nust L del eel
by fundamental exploration.nbsp;uetected

Dehcate annual or . obust perennial plants, sometimes mo,-e or less sum„tesco„t
at the base. Roots of the annual species thin, more or less fusiform, those of \'
perennials much thicker and m deseil-plants often provided wi,h a tuquot;, c Culms
aespitose, many rem a rootstocK or simple, the .„ot^tock „.„.-e or les a d ^o.nt
messul rntescently branched or creeping with short ra, ely long stolons anrlvTed

Hth both k.nds of .nnovations, sometimes there are at the flowerin« ti™ bu few

uaseor tiou most of the nodes, e,-ect or ascending, terete to st,\'onquot;lv comnressed

lyaj ue nans not rarely pubescent with adpressed or spreading hairs or
lanate or woolly, ,f the lower internodes a.-e Late, the t^^pe,- one are ™t S

, d ns y long-bear ed, the hairs spreading, so,uetit«es a viscid ring bebw ^e
nodes the culm-nodes not ,a,ely tumid, much swollen and protrndi,quot;. abo™ 1 e
heath-nodes; sheaths tight, tcete or comp,-essed, striate or q,!ite sm th mo e o
I s scrabous between the nerves, not ,arely with spreading long hai quot;s „r
lanate-pnbescent all over o,- somentimes ve,-y woolly with a mot^ or less deckluot

tomentum, sometimes coarsely hairy by tubercle-based hairs, especially along the
margins and in the upper part, the margins mostly rather broad and more or less
hj-aline and sometimes with a characteristic pubescence or finely ciliate there; in
much branched plants the sheaths more or less slipping from the stems, keeled below
and more or less open and rolled up at the summit, the lower ones falling off at
maturity and most of the lower internodes thus naked, the lowermost sheaths not
rarely reduced to scales with very short or wanting blades, the scales mostly pale
and shining or sometimes more or less lanate with a fugaceous wool; internodes
very different in length, mostly about equal with exception of the uppermost one
which is the peduncle of the inflorescence, in some species the internodes alternately
very long and very short, thus bringing the leaves approximately in pairs, the culms
sometimes but few-noded and the nodes placed together at the base of the stems
in which case the sheaths and blades are not rarely very long, forming groups of
aggregated blades, the culms sometimes without a node, in reality 1-noded, the node
placed at the very base of the culm, the leaves in that case quite basal; ligules nearly
always a very short ciliate rim, sometimes with longer hairs and ciHate, the auricles
thickened or not, nearly glabrous or mostly densely pubescent, in different species
with long, white, spreading hairs or bearded laterally with a tuft of spreading or
retlexedhairs, sometimes with a villous or distinctly pubescent line across the collar
of the sheath or with a very short membrane as a so-called ligula externa, the
auricles of the leaves of the innovations mostly long-bearbed even if those of
the culm-leaves are ciliate only; blades different in form and length, sometimes quite
flat and up to 5 mm. broad, or rarely 9 mm. broad, nearly always with a xerophytic
structure, sometimes flat only at the very base, soon becoming involute or convo-
lute, or convolute throughout, sometimes very rigid and almost junciform, ending
in a long setaceous point, not rarely very acute and pungent, the blades erect and
adpressed or divaricately spreading, sometimes very short and spine-like, sometimes
extraordinarily long, mostly shorter than the culms but in some species much
overtopping the panicles, lower surface of the blades striate, glabrous or scaberu-
lous, the upper surface scabrous or hirtellous or densely pubescent and sometimes
lanate on both surfaces, few- to many-nerved, the nerves prominent, the midnerve not
or sometimes much thickened, the marginal nerves not rarely difJerent from the other
ones and very thick, forming bands of sclerenchyma with scabrous margins; panicles
exserted or more or less sheathed by the uppermost leaf, the peduncle sometimes very
short, glabrous or scabrous, very different in form and outline, sometimes much reduced
and consisting only of a few spikelets, commonly more compound with numerous
flowers, dense and spike-like, more or less interrupted at the base, the branches
spikelet-bearing to the base, sometimes interrupted all over, or very lax and open,
the branches erect or ascending or divaricately spreading, sometimes reflexed or
drooping, more or less naked at the base, sometimes naked over a very long
distance, the axis of the panicle terete or angulous, sometimes triquetrous, glabrous
to very scabrous sometimes with long hairs here and there, branches nearly always

thickened in the axils, the axils smooth or pubescent and ciliate, sometimes with
a very prominent tuft of hairs or a Hake of wool, the branches and branchlets
glabrous or scabrous, erect or ascending or divaricately spreading, the llowers
equally distributed over the panicle, or the spikelets not rarely densely congested
at the summit of the branches and branchlets, forming tliere false spikes with
imbricate spikelets, the pedicels scarcely developed, commonly as long as or much
shorter than the glumes, sometimes very long, very thin and capillary, flexuous
or curved and the spikelets more or less drooping, the pedicels very scabrous to
glabrous, terete or compressed, clavate or subclavate at the apex, not rarely with
a pencil of hairs at the tip or with a lateral, small tuft of hairs; spikelets typically
1-flowered, sometimes, but very rarely, with a prolongation of the rhachis and a
second llower, such spikelets always mixed with the normal llowers of a panicle,
the spikelets very variable, yellowish to straw-coloured, often with a dark spot
near the base or tinged with red or purple, sometimes purple throughout or golden-
yellow, sometimes shining, glabrous and smooth or scabrous and pubescent on the
back, sometimes with spreading long or short hairs all over or only at the middle
or along the mai-gins, rarely the hairs with tubercles at the base, the glumes
mostly scabrous on the keel, at least the lower one, the upper glume mostly with
a smooth keel, the glumes 1-nerved to 5-nerved, sometimes many-nerved, not rarely with
more or less developed additional side-nerves, the lateral nerves mostly shorter or much
shorter than the midnerve, sometimes arching and anastoitiosing with the midnerve,
the tips acute to acuminate, sometimes very long-awned and the awns longer than
the body of the glume, not rarely one or both glumes distinctly bifid at the apex
with an awn or mucro\' from the sinus, the lateral lobes or setulae more or less
developed, sometimes very long and subulate, sometimes short and obtuse or
rounded at the tip; lower glume much shorter or about as long as the upper one, not
rarely the position of the glumes inverse and the lower one much longer than the uppeiquot;,
the upper one sometimes extraordinarily short and in that case nearly totally
hidden by the lower glume; lemma consisting of a body and a prolongation at its
base, called the callus, the body of the lemma quite glabrous and shining or mostly
punctulatp under a strong lens, sometimes more or less scabrous, especially above
or tuberculate-scabrous in lines from below the middle to the summit, the raised
parts whitish at maturity and the background dark, sometimes tuberculate all over,
very rarely with some adpressed or spreading hairs, the lemma mostly tightly
inrolled, tubulous, the margins overlapping, or sometimes the margins only slightly
inrolled and the lemma thus deeply furrowed at the ventral side and there
sometimes with rows of spiny hairs, the callus more or less oblique, compressed
and laterally hairy, with longer hairs at the junction with the lemma, the hairs
sometimes longer and exceeding the base of the lemma or sometimes up to half as
long as the body, the callus sometimes very short and scarcely mm. long,
sometimes up to 5 mm. long, with a naked tip which is very obtuse and rounded
or subtruncate at the tip, sometimes very acute, conical and pungent, sometimes

very distinctly and deeply bifid, the two lobes very acute and more or less spreading,
sometimes the callus is nearly quite glabrous or with a slight pubescence only at
the Junction with the lemma; body of the lemma gradually narrowed above or
equally broad, passing into a column or awnstipe which is more or less developed
and which is sometimes quite absent and the body of the lemma directly passing
into the awns, sometimes there is only a short rostrum in which case we call it
a beak, the beak or the column is perfectly straight or mostly strongly twisted,
sometimes very thin and elegant, sometimes very thick, the column is rarelymore
or less pubescent or hairy, in some species the summit of the lemma is lobed and
the column placed between the short obtuse lobes, in that case theie is always an
articulation at the summit between the lobes, the articulation, if present, is sometimes
found at the summit- of the column in which case the awns are not deciduous,
sometimes we find that the body of the lemma is articulated in or above the
middle, if there is no articulation at the summit of the column we find sometimes
an indication in the form of a nodule just below the. branching point of the awns;
the awns are nearly glabrous or commonly rough or very scabrous, in some
sections all the awns or the central one is feathery and the feathers are erect or
much spreading, white or canescent or sometimes golden-yellow, the hairs are not
always of the same length, they mostly become gradually shorter upwards, the
very tip is not rarely exserted as a naked scaberulous point, the feathery part of
the awns is very obtuse in outline or very acute, in both cases with or without
a naked tip, the awns are equal or very unequal, sometimes the central one strongly
curved in a semicircle and reflexed, sometimes all the awns reflexed, not rarely
all the awns are spirally contorted at the base or the central one arcuate-contorted
only, or all the awns form at the base a loose spiral and the upper parts are
straight, sometimes the lateral awns are very short or nearly wanting and the
place of the lateral awns is only indicated as a well-marked spot under a strong
lens, the lateral awns are sometimes very thin and of a diflerent structure; the
inner valve (pale) always very short, narrow to oblong, nerveless or 2-nerved,
sometimes many-nerved; lodicules finely nerved, two or three, sometimes absent;
stamens 1 or 3. Ovary always glabrous, the styles distinct but short; stigmas
plumose, laterally exserted; caryopsis slender, cylindric to oblong-cylindric, terete
or sometimes grooved, tightly embraced by the lemma, the hilum linear, nearly
as long as the grain; embryo different in form, long or short.

There are 490 described species, 7 of them do not belong to our genus, about
320 species are accepted as valid in this work, the other ones are synonyms or
treated by me as varieties or subspecies.

The species are distributed over the tropical and temperate parts of the world,
mostly on plains or savannas and on open ground, many of them also on
rockey hills and highlands, in the mountains ascending to elevations of 3500
meter, many of them typical desert-plants and| not rarely forming there the
only vegetation.

There is no articulation at all, neither between the body of the lemma
and the column, nor between the column and the awns. Very rarely
the prolongation of the lemma breaks off at maturity, but in that
case there is no special tissue and the rupture wliich is artificial is
caused by the different texture of the coriaceous lemma and the thin,
papery prolongation...................G.

Body of the lemma with an articulation placed at or above the middle,
the awns with the column break off at maturity together with the
conical upper part of the lemma. Central awn plumose, lateral ones
commonly much thinner, naked or feathery, rarely in one insufliciently

Central awn always feathery, at least in the upper part, lateral awns
feathery or quite naked, there is a more or less developed column

There is no prolongation of the lemma, a column or beak is totally absent,
the body of thé lemma immediately passes into the 3 awns, the arti-
culation placed just between the awns and the summit of the lemma,
............Section PSEUDOCHAETARIA HENR.

5.nbsp;The articulation is placed at the base of the column or beak, at the summit

6. Lateral awns much reduced, very short, minute, obsolete or totally wanting,
sometimes developed and up to 6 mm. long, but in that case always
very thin and different in texture, very fme, merely bristles, whereas

Lateral awns well-developed, sometimes much shorter than the. central
one or only half as long, sometimes much shorter although in that
case of quite the same structure as the central awn, column of awns
well-developed or not present at all, there is sometimes only a short beak.

Schistachne was described as a genus by A. Figari and J. Denotaris in the
year 1851 as follows: „Gluma 2-valvis, unillora, cum secundi fioris rudimento ad
valvulae superioris axillam. Valvulae papyraceae, canaliculatae,3-nerviae,subaequales.
Inferior apice rotundato emarginata superiorem angustiorem, convolutam, apice
breviter bifidam, amplectens, utraque llosculo stipitato duplo longior. Palea inferior
membranacea, convoluta, glabra, obsolete 3-nervis, ad medium lineola anulari,
horizontali notata, ibique in anthesi circumscissa, parte superiore cuculliformi cum
arista continua, decidua. Arista supra basim 3-partita ; laciniae laterales filiformes
scabrldae, media supra ad apicem plumosa dimidio minores. Palea superior mem-
branacea, glabra, enervis, brevissima. Paleolae 2, membranaceae, obovatae. Stamina 3.
Antherae lineares nudae. Ovarium glabrum. Stigmata 2 plumosa. Flos abortivus,
stipituliformis, glaber.quot;

The type is Schistachne ciliata, the only species mentioned, based upon Aristida
ciliata Desf.-Deltl. Fl. aegypt. ill. p. 75. 174. tab. 13. fig. 3. a. b. c. Kuntii Agrost.
I. p. 195. Decaisn. Fl. sinaic. n. 54 Tausch Aristid. 1. c. p. 127.

Clarissimus Delile structuram paleae inferioris huiusce speciei, iam antea bene
quot;ovit, 1. enim c. inquit „elle est articulée circulairement, son sommet caduc est roidé
ew cornetquot;. Character, ni fallimur, maioris momenti ac ille quo Stipagrostides a
reliquis Aristidis discriminantur.quot;

In the year 1813, four years after the publication of Aristida ciliata, Delile
found the character of the articulated lemma. The striking rupture of the lemma
was afterwards also observed by other botanists. Nees, describing his Arthratherum
ciliatum in Linnaea VII. (1832) p. 289, says: „singttlare hac in specie, quod stipes
aristae basi in conum cavum convolvatur.quot; In his Agrostographia capensis (1841) this

*) Accad. RIe delle Sc. di Torino Class, di Sc. Fis. et Mat. Ser. II. Tom. XII. p. 252; Agrostograpliiae
aegyptiacae Fragmenta, Pars I,

is repeated under Arthratherum Schimperi Nees, which is the same as Aristida
ciliata, but it seems tliat Nees was not convinced that this character was important,
he described another species belonging to our section and indicated only the
tubulous stipe. (Compare Arthratherum namaquense on p. 185 of the Agrost. capensis).

Trinius and Ruprecht, the monographers of the genus Aristida lixed in the year
1842 no more attention to the curious articulation as did Nees, they mentioned
in their descriptions only the ,,stipile conico intus cavoquot; on p. \'164 and 174 of their
work Spec. Gram. Stipac. and Steudel, who described a third species, did the same.

In my work the sections of the genus are based on the absence or presence of
the articulation and on the place of it, therefore I have taken up the genus
Schislachne as a section of Aristida, and characterized it in the same way as did
Figari and Denotaris. x\\11 the species of this section have an articulation nearly
at, or slightly above the middle of the lemma, and the column, if present, is
deciduous with the upper half of the valve.

The species of this section are limited to Africa, hitherto there are about 8 species
known, one of them very common in South and North Africa.

1.nbsp;Panicle very dense, spike-like, the spikelets nearly sessile, position of the

glumes inver.se, the lower distinctly longer than the upper one . . 2.
Panicle not dense or spike-like, loose or more or less contracted, the spikelets
pedicelled, position of the glumes not inverse, the lower shorter or
much shorter than the upper one.............3.

in upper 1/4 part, column about 4 mm. long, straight, not twisted.
Insufficiently known species, probably perennial, with glabrous upper
sheaths and internodes; panicle 6—7 cm. long, up to 1 cm. broad,
with glabrous rhachis, spikelets with short, about 3 mm. long, glabrous
pedicels; lower gluwe3-nerved, awned, the summit somewhat laciniate,
17 mm. long, upper one 1-nerved, smooth, 13 mm. long; lemma smooth,
inclusive of the densely hairy, acute, about I\'/g mm. long callus, up
to 6 mm. long, column firm, not or scarcely twisted, glabrous; awns
strictly erect, the central one thick and firm, at least 4 cm, long,
naked, the upper part is broken oil and it is not known whether the
upper part of the central awn is plumose or not, lateral awns much
shorter, finer, merely bristles, at least 2 cm. long. South West Afi-ica:
Damaraland......................

Lower glume hairy, articulation at the middle of the lemma, column longer,
up to 10 mm. long, strongly twisted.

Glaucous perennial, fascicled or subcaespitose from a more or less
bi\'anched rootstock, innovations few, extravaginal ; culms simple, up to
50 cm. hifgt;h, erect or geniculate at the nodes, terete, substriate, minutely
scaberulous or glabrous, 2—4-noded, nodes glabrous, those of tlie culms
slightly swollen and protruding; lower sheaths reduced and scale-like,
with very short, scarcely i cm. long blades, striate, scaberulous, upper
sheaths tight, scaberulous or scabrous, pruinose, shorter than the
internodes, ligule a short ciliate rim, auricles shortly ciliate, collar
smooth • blades convolute or setaceous, those of the innovations up to
6 or 7 cm. long, the culm-blades up to 20 cm. long, ending in a long
setaceous point, glabrous and pruinose beneath, hirtellous on the upper
surface; panicle 4—7 cm. long, exclusive of the awns, up to 1 cm.
broad axis scaberulous, the lowermost axils of the branches sometimes
with a tuft: of hairs, branches solitary, divided nearly from the base,
the scabrous branchlets very short, the llowers densely congested with
scabrous, 1 mm. long, subclavate pedicels ; spikelets yellowish orgreenish,
quot;iumes narrowly linear or lanceolate, acuminate, both 3-nerved, the
midnerve much stronger, the lower glume very scabrous and with long
spreading hairs, especially on the back, 16-17 mm. long, the upper
glume about 14 mm. long, glabrous or scaberulous only; lemma with
a 2 mm. long, very acute callus which is adpressedly hairy below and
long-pilose above, the body of the lemma 8—9 mm. long, the lower part
below the articulation densely punctulate-scabrous, strongly 3-nerved
and together with the callus 5 mm. long, the upper part of the lemma
above the articulation quite smooth, conical, gradually narrowed into
the slightly scaberulous column, central awn plumose and long-feathery
above the middle with an excurrent naked tip, the feathery part obtuse
in outline, 0-8 cm. long, the lateral awns very line, scaberulous or
smooth, up to 2V2 cm. long. South West Afrika: Hereroland and

3. All the awns of the lemma plumose, mostly all over or the lateral ones not
so densely feathery as the central one............

Internodes glabrous or scaberulous ; panicle-branches and branchlets scabrous
or glabrous, never woolly-pubescent or tomentose, pedicels not or
scarcely thickened, scabrous............... .

and branchlets woolly-pubescent, the pedicels with subclavate woolly tips.
Elegant, erect or ascending glaucous perennial, culms simple, branched
from a more or less suffrutescent base, 15—20 cm. or sometimes up
to 30 cm. high, densely woolly at and below the nodes, otherwise
pubescent, terete or subcompressed; sheaths somewhat shorter than
the internodes, tight, pubescent with adpressed hairs, the sheath-nodes
with a ring or tuft of long white hairs, densely tomentose or woolly, ligules
a ciliate rim, auricles densely bearded, the hairs united into a ring at
the junction of the blade and the sheath; blades convolute, filiform,
subpungent, rigid, glaucous, adpressed-pubescent in lines or becoming
glabrous beneath, more or less scabrous-hirtellous on the upper surface,
curved, gradually narrowed but not setaceously pointed; panicle narrow-
but rather loose, up to 10 cm. long, mostly shorter, shortly exserted
or sheathed by the uppermost leaf at the base, peduncle pubescent or
hairy, angulous or subterete, axis of panicle subterete, adpressed-hairy,
the axils densely woolly, branches binate, erect, simple or the lowest
branched above the middle, naked in lower part, up to 5 cm. long,
few-flowered, mostly only 2—4-spiculate, pubescent, the pedicels erect
or more or less curved, up to 7 mm. long or sometimes as long as
the glumes; spikelets yellowish, glumes unequal, glabrous and smooth,
3-nerved, the lateral nerves shorter than the midnerve and slightly
anastomosing with it, the lower glume 9 mm. long, the upper one
11 mm. long, both acuminate and mucronate from a slightly bifid
apex, both scaberulous only on the keel above; lemma glabrous, lan-
ceolate-oblong, rounded at the base, abruptly narrowed into the 2 mm.
long, very acute, long-pointed, very narrow, densely hairy callus, the
body of the lemma exclusive of the callus about 3 mm. long, disarti-
culating just above the middle, keeled and strongly 3-nerved especi-
ally above the articulation, awns deciduous with the upper half of
the lemma, subequal or the central one slightly longer, plumose all
along, 6—7 mm. or sometimes up to 10 mm. long, tips not exserted,
feathery part very obtuse in outline. South Africa: Central Region,
Aliwal North.....

Suffrutescent with a long creeping rhizome, stoloniferous, with extra-
vaginal innovations, covered with densely imbricate scale-like sheaths,
the latter glabrous except the woolly lower margins, -with reduced
spine-like blades, culms fascicled, ascending or prostrate, woody below,
simple or often with fascicles of erect branches from the lower and
the middle nodes, sometimes very long and more than 1 meter high.

glabrous and smooth; sheaths very tight, firm, pallid, glabrous and
smooth or more or less hairy, especially along the margins, longer or
shorter than the internodes, ligules and auricles minutely ciliate only,
collar smooth; blades setaceous or subulate, convolute, the lower ones
very short, very rigid and pungent, the upper ones longer, up to 20 cm.
long, glaucous, glabrous and smooth beneath, hispidulous on the upper
surface; panicles more or less exserted, narrow, linear, more or less
contracted but rather loose, up to 20 cm. long or .mostly shorter,
rhachis straight or subllexuous, nearly smooth, branches solitary, nearly
sessile erect or suberect, bipartite nearly from the base or the branchlets
fascicled, the lower ones up to 5 cm. long, scabrous and filiform like
the branchlets, lateral spikelets with pedicels much shorter than the
glumes; spikelets yellowish, erect, glumes rather firm, unequal, lanceo-
late to \'linear-lanceolate, acuminate, tips minutely truncate or slightly
bifid, 3-nerved, glabrous, involute, the lower 12 mm., the upper one
15 mm. long; lemma subcylindric, glabrous, the conical callus about
2 mm. long, acute and pointed, hairy, the lemma produced into a
straio\'ht oiquot; slightly twisted very short beak, the body articulated at
or below the middle, total length of lemma and column up to 10mm.;

ones about 20 mm., all the awns plumose [to the very tips, the central
one subobtuse, the lateral ones subacute in outline, the side-bristles
finer than the central awn and scantily adpressedly plumose at
the base more densely so above. South Africa: From Great and Little
Namaqualand to Griqualand West, south to the Central and Coast Region.

Culms 1—2-noded, the nodes hairy, bearded with more or less spreading
long white hairs.

A hybrid between Aristida capensis and Aristida ciliata, agreeing in
habit and vegetative characters with the former but the nodes with
divaricate deciduous hairs, the sheaths striate with densely bearded
auricles; blades rather short, curved, 5—6 cm. long; panicle exserted,
strictly erect, rather tew-flowered as in A. ciliata, the branches erect
or ascending only, slightly scabrous like the pedicels; spikelets lan-
ceolate, agre°eing with those of A. capensis but the glumes not papery
or thin \'but very firm or chartaceous in texture, both 3-nerved, yellowish-
brown\'purple-mottled at the base as in A. ciliata, about equal, 14—16
mm. long, acutish or subobtuse, with minutely ciliolate tips, the column
slightly\'^twisted and glabrous; awns very unequal, the central one
feathery all along to the very tip, obtuse in outline, up to 4 cm. long,
the lateral ones half as long as the central one or scarcely up to

21/2 cm. long, witli scabrous long-exserted tips, more or less sparingly
or remotely hairy at the middle; feathers mostly longer than quot;in
A. capensis and more spreading, as in A. ciliata; articulation at the
summit of the body of the lemma as in A. capensis, or the lemma is
articulated at about 1/4 below the summit. See also in the section
Stipagrostis. The hybrid is observed between the parents in South West
Af rica: Little Namaqualand

6.nbsp;Glumes of a very firm texture, cartilaginous, glabrous or rigidly ciliate,

linear-oblong, subequal, not convolute, obtuse, with emarginate and
slightly ciliate tips . ..................

Glumes of a thin structure, hyaline, papery, glabrous or softly hairy, linear-
lanceolate, unequal, mostly convolute, acuminate, with minutely truncate
tips.....................

Compactly caespitose perennial, culms up to 50 cm. long, 2-3-noded,
many in a tuft, fascicled, erect to geniculately ascending from a robust
more or less sulfrutescent rootstock; innovations forming rather short
and dense tufts with densely lanate sheaths and short recurved firm,
subulate blades, culms terete, smooth, slightly striate, swollen and
somewhat viscous below^ the sheath-nodes, which are more or less
constricted and perfectly smooth, sheaths of the culm-blades shorter
than or as long as the internodes, scabrous or shortly pubescent only,
especially along the margins, ligule a shortly hairy rim, auricles pubes-
cent or very shortly ciliate, collar glabrous; blades of innovations 1—2
cm. or sometimes up to 6 cm. long, very firm, those of the culm-leaves
much longer and up to 12 cm. long, all the blades nearly glabrous
beneath and densely shortly villous-pubescent or pilose on the upper
surface, ending in a pungent tip; panicle exserted or at first more or
less sheathed by the uppermost leaf, up to 15 cm. long or mostly shorter,
axis terete or subcompressed, striate or grooved above, nearly smooth!
many-flowered, somewhat contracted but loose with erect or adpressed
filiform solitary branches, the latter divided nearly from the base,
bipartite or more or less fascicled, nearly smooth, the lower and longer
ones up to 7 cm. long, exclusive of the awns, bearing rather remote
mostly solitary flowers, the lateral spikelets very shortly pedicelled,
the nearly glabrous pedicels swollen and clavate at the tips, sometimes
the pedicels as long as the glumes; spikelets straw-coloured, a purple
spot at the base, glumes about equal, 10 and 11 mm. long or sometimes
shorter, 3-nerved, boat-shaped, very firm, glabrous or sometimes rigidly
cihate; lemma tubulous, glabrous, smooth, with a iong-hairy, acute.

nearly 2 mm. long callus, up to 10 mm. long, articulated just above
the middle, column of awns nearly totally wanting, slightly indicated
only as a beak; central awn up to cm. long, naked in lower V3
part, plumose above nearly to the very tip, the tip short, naked and
slightly exserted, the feathery part subacute in outline, lateral awns
naked, up to 2 cm. long, all the awns geniculate at the branching-
point and somewhat contorted at the base. South West Africa: Great

Glumes very obtuse, not or scarcely ciliate at the apex, 8 and
9 mm. long, the upper one with long, rigid, hyaline hairs
in the upper part near the midnerve. Damaraland ....

Nodes long-bearded with spreading hairs, the hairs sometimes deciduous
in old culms.

Compactly caespitose perennial with numerous short innovations or
not rarely with longer up to 15 cm. long innovation-blades, culms
exserted few-noded, erect or geniculately ascending, terete, nearly
smooth, with a prominent viscous ring below the nodes, up to 60 cm.
lono\' or not rarely much shorter and only 30 cm. long, inclusive of
the panicle; sheaths crowded at the base, the lowermost very broad,
pale-yellow or whitish, firm and persistent, densely striate, glabrous
or more or less woolly along the margins, sometimes quite villous, the
upper sheaths tight, shorter than the internodes, striate, glabrous or
more or less pubescent in some varieties, ligule a short ciliate rim,
auricles shortly ciliate, those of the innovations long-bearded, collar
o\'labrous; blades very diiferent in length, those of the innovations
sometimes very short, coarsely .setaceous, mostly convolute throughout,
more or less recurved or not rarely up to 15 cm. long, rigid, striate,
glabrous and smooth beneath, minutely hairy or hirtellous on the
upper surface, sometimes more or less pungent; panicle narrow, but
open and sometimes very loose, usually contracted and strictly erect,
linear-oblong, iO-15 cm. long with a glabrous nearly smooth axis,
branches ei-ect, solitary, or bipartite nearly trom the base with (iliform
few-llowered branchlets, the tips of the pedicels clavate, those of the
lateral flowers very short; spikelets linear-oblong, pale or straw-coloured
often with a purple spot at the base, the glumes nearly equal, linear-
oblonlt;T, emarginate at the apex, very obtuse or subacute, not awned,
very Mrm, 3-nerved, usually glabrous but sometimes with hyaline

hairs, nearly always pubescent at the summit; lemma cyhndric much
shorter than the 9 and 10 mm. long glumes, the long-hairy very acute
callus about 2 mm. long, the body of the lemma smooth, gradually
narrowed into a straight or slightly twisted filiform, well-developed
column, the latter reaching the summit of the glumes or distinctly
exserted, total length of lemma with callus and column 12—14 mm.;
central awn up to cm. long or sometimes longer, divaricate,\'
geniculate at the branching-point of the 3 awns, naked or scantily
and adpressedly pubescent at the base, plumose from the middle to
the very tip or with a scabrous excurrent point, lateral awns very
line, mostly erect, minutely scabrous only, IV2—2 cm. long, not
contorted at the base. Widely distributed from South Africa quot;to the
Sahara, east to Sinai and Arabia..............

Sheaths and blades, especially those of the innovations densely
lanate or villous; summit of the central awn but slightly
excurrent and shortly hairy, the plumose part of the central
awn acute in outhne. Great Namaqualand........

Sheaths and blades not woolly or villous, slightly hairy sometimes
near the margins below or with a short pubescence only.

Glumes or at least one of them with long hyaline hairs.
Both glumes with spreading hyaline hairs, the lower one
rigidly ciliate nearly all over except the very obtuse tip,
the upper glume ciliate-pectinate only on the back, the
hairs placed in rows between the nerves, exserted
part of the column nearly 5 mm. long; central awn
sparingly feathery at the base, densely plumose above
with a naked scabrous rather long-exserted tip, the plumose
part very obtuse in outline.

Only the upper glume with rigid spreading hairs on the
back, column exserted; lemma, inclusive of the callus and
column up to 15 mm. long, central awn naked or scabe-
rulous only in lower part, the tip excurrent as a scabrous
point, the feathery part subobtuse or subacute in outline.
Together with the type, but rare.........

Central awn plumose from the middle to the very tip,
without a naked exserted tip, the feathery part very

Pedicels long, capillary, as long as or longer than the glumes, the latter
about 8quot;mm. long, panicles more or less elluse.

Densely caespitose elegant erect perennial with a not very thick,
abbreviate rootstock, mostly 30—50 cm. high, but not rarely much
shorter or longer, culms mostly sheathed all along, simple, erectly
ascendino\', 2—i-- noded, the purplish nodes glabrous and constricted,
internodes terete and slightly striate; sheaths glaucous, glabrous or
puberulous, the lower ones shorter, the upper ones very long, ligule
a ciliate rim, auricles bearded, collar glabrous; radical leaves densely
cono-ested, somewhat curved or suberect, convolute throughout,
acuminate rioid, up to 5 cm. long, or in robust specimens up to 10 cm.
lonoquot;, those of the culms very narrow, plicate-convolute, subulate-
acuminate, sulcate-striate and scabrid-puberulous on both surfaces;
panicle erect, many-llowered or few-flowered in meagre specimens,
rather loose, \'linear-oblong, up to 30 cm. long in robust specimens,
mostly much shorter and less than 15 cm. long, axis compressed or
ano\'ulous, glabrous, branches mostly solitary, divided nearly from the
base, the branchlets fascicled or nearly so, iterately branched, the
branchlets few-flowered and ascending, flexuous and filiform, nearly
smooth, pedicels slightly thickened and nearly glabrous; spikelets pale,
yellow \'or greenish, purplish at the base, glumes nearly equal, keeled,
acute, not quot;awned, hairy all over or the margins and tips glabrous,
the hairs very soft and more or less spreading, both glumes 3-nerved,
the lower one 7 mm., the upper one 8 mm. long; lemma tubulous,
glabrous, 3-nerved, the very acute densely hairy callus scarcely 2 mm.
îoncT the body of the lemma gradually narrowed into a scarcely
deve\'loped not twisted beak, the total length of the lemma with the
callus to the branching-point of the awns is 6-7 mm., articulation just
above the middle of the lemma; central awn naked at the base, densely
adpressedly feathery above to the very tip, up to 2 cm. long, the tip
scantily feathery and very acute in outline, lateral awns spreading,
naked,quot; about half as long as the central one. South West Africa:

Glumes commonly shorter than in the type, 6 and 7 mm. long,
quite glabrous. South Angola......var. calva Henr.

Pedicels very short, nearly sessile, glumes 13—14 mm. long, panicle more
or less contracted.

Densely caespitose glaucous erect perennial with intra vaginal innovations,
culms erect, sometimes geniculate at the nodes, elegant, 25—40 cm.
high, simple, 2—3-noded, the glabrous nodes equally distributed,
internodes terete, scarcely striate, slightly thickened and grooved
below the nodes and with depressed crateriform glands, smooth or
scaberulous; sheaths of the lower blades more or less reduced, 1—2 cm.
long, rather thin, sometimes papery, densely striate, . scabrous, pale
yellowish with broad hyaline margins, those of the culm-leaves tight,
terete, scaberulous or scabrous especially along the margins, striate,
sometimes slightly keeled, shorter than the internodes, ligule a ciliolate
rim, auricles densely ciliate and more or less bearded or the long
hairs wanting, collar glabrous; blades erect, linear, not very rigid,
setaceously convolute throughout, scarcely 1 mm. wide w^hen expanded,
acuminate, 12—15 cm. long, very scabrous on both surfaces and
hirtellous on the upper surface, ending in a long setaceous point;
panicle erect, linear, contracted and very narrow but rather lax and
interrupted at the base, including the spikelets and awns up to 20 cm.
long, exserted or at first sheathed by the uppermost leaf, axis terete
and nearly smooth below, like the lower branches with depressed
crateriform glands, more or less angulous and scabrous above, branches
solitary or binate, scaberulous or nearly smooth, up to 10 mm. long,
branchlets bearing but one erect adpressed flower, the lateral pedicels very
short, nearly sessile and up to 3 mm. long, the other ones longer {jedicelled
but the pedicels always much shorter than the glumes, all the pedicels
scabrous, laterally grooved and slightly thickened; spikelets strictly
erect, whitish, glumes linear-lanceolate, about equal or slightly unequal,
the lower 12—13 mm. long, 3-nerved or sub-5-nerved by additional
shorter side nerves, acute, shortly awned, more or less hairy with soft
spreading hairs, the upper glume 13—14 mm. long, narrower, 3-nerved
or sub-5-nerved, acute, or with an inrolled subobtuse summit, not so
densely hairy as the lower glume; lemma glabrous, linear-tubulous,
the callus IV2 mm. long, very acute, densely hairy, the body of the
lemma inclusive of the callus 10—11 mm. long, articulation at the
middle, gradually narrowed into a nearly smooth, distinctly twisted

about 4 mm. long column; central awn spreading, up to 6 cm. long,
naked in lower 1/4 part, densely long-plumose above, with an excurrent
naked tip, the feathery part acutish in outline, lateral awns very thin,
erect, naked, up to 15 mm. long. South West Africa: Hereroland and

The genus Stipagrosiiö was described by Neks in Linnaea, Vol. Vll. (1832) p. 290
i\'s follows: „Spicula unillora. Glumae duae membranaceae, aequales, llosculo longiores.
l^\'losculus callo pedicellatus, bivalvis: valvula inferior chartaceo-membranacea, con-
^\'oluta, apice emarginato-biloba, inter lobos arista articulo inserta decidua trifida
instructa; superior brevior obtusa. Lodiculae magnae membranaceae, spathulato-
cochleariformes. Caryopsis subcylindrica, unisulcata, libera, valvula ilosculi subindu-
rata tecta. Inllorescentia racemoso-paniculata. Glumae carinatae, trinerves. Aristae
der.s medius apice plumosus, baiba obtusa nec nudo dentis apice rnucronata. —

Dilfert Stipagrostis a reliquis Stipeis arista trifurca praeditis arista inter lobos
valvulae inserla, neque a valvula in aristam attemiata proiiciscente. Quorum generum,
gt;\'isi, cl. Trinio praeeunte, in unum omnia conjungere placeat, breves facilesque

characteres invenies:
Stipeae, Aristideae (Arista valvulae inferioris flosculi termi-

Arthratherum Pal. de IJeauv. Arista annulo discreta apicique valvulae attenuate
i\'ltegro applicata, Integra decidua.

proprii genei\'is esse videtur.
Stipagrostis N. ab E. Arista annulo discreta, inter lobos valvulae apice bilobae

Aristida Pal. de Deauv. Arista annulo discreta, inter setas valvulae apice bisetae
inserta, simplex, decidua cum valvulae setis aristam trilidam fingens. (Si talis
structurae vera exempla inveniantur.)

Ghaetaria Pal. de Beauv. Arista, sen potius seta, trifida cum apice attenuato
Ilosculi continua, persistens.quot;

The only species described was Stipagrostis capensis N. ab E., which is the type
of the genus. From the very accurate description and from the specimen in the
Berlin Herbarium, we see that it is quite the same as Aristida obtusa, described
already by Dklile from North Africa in the year 1813. It is necessary to observe
that Nees described the sheaths of his species as glabrous („vaginae glabrae, ad
latus ejus minute barbataequot;), because in the year 1841 he gives on p. 171 of his
\'Flora Africae the same descrijition but on p. \'180 under the descri[)tion oïArthra-
therum obtusum the sheaths are described as „lanuginosaequot;. Deui.e\'s specimens have

glabroussbeathsanditis very curious that the.plants of Aristida obtusa mentioned by
Nees himself (Schimper no. 163, Siebei-) have glabrous sheaths. Trinius and Ruprecht

say under Aristida obtusa: „culmo nodis vaginisque glaberrimis, Vaginae in speci-
minibus examinatis semper glabrae ut quoque Delile describit.quot; Nees described thus
the same species under two dilferent genera and the statement of the woolly sheaths
under Arthratherum obtusuni was erroneous.

The Russian monographers accepted the genus of Nees as a section of Aristida
but modified the character and they placed all the species with plumose awns in
this section with the character: „Aristae caducae setis pennatisquot;.

The most important character mentioned by Nees in his description of the genus
Stipagrostis is the obtusely bilobed valve with a column from the sinus and this is
the only diagnostic character. If we base the sectionnbsp;only on this character

of the bilobed summit of the lemma, we must exclude many species with a very
short column or a nearly wanting awnstipe. In Aristida sabnlicola the summit of
the valve is so strongly bilobed that the two lobes are produced beyond the insertion
of the 3 awns as two hairy well-develo[)ed appendages, on the other hand we find
in Aristida pennata that the lobes ai-e united with the lower part of the column
Species as A. uniplnmis, A. hrevifolia and A. subacaulis, true Stipagrostis-species as
to the bilobed apex of the lemma, were described by Nees himself under the genus
Arthratherum. It is not advisable to make more sections in this group; the chai\'acter
so accurately observed by Nees is not always easy to fix and is absent or |)resent
on the same specimen. I have therefore accepted the scction with the following
characters: „Lemma always articulated at the summit, with or loithout a vMl-developed
column, aicns at least the central one long-feathery

A group of about 38 species, totally limited to the western part of the Old World
distributed from South. Africa to the Sahara, Arabia, Turkestan and Persia to
Western Tibet. One species occurs also in European Russia.

1.nbsp;All the awns plumose with long spreading hairs, or the lateral ones naked

at the base and plumose only above the middle, sometimes the central
awn with longer and more copious hairs than the lateral ones ... 2.

Only the central awn plumose with spreading hairs, the lateral ones quite
naked or sometimes very sparingly and scantily adpressed-ciliate-
\'pubescent.........................

2.nbsp;Internodes at least the lower ones ahvays densely woolly, awns not plumose

all over, mostly the central awn bearded nearly from the base to the
summit and the lateral ones naked below and plumose in the upper part. 3.

Internodes glabrous or minutely puberulous only, awns plumose from the
base to the very tip or sometimes the tip slightly excurrent as a naked
or scabrous bristle,nbsp;...........5,

Caespitose erect or ascending about 30 cm. high perennial, branched only
at the base, with a stout rootstock and intra- and extra vaginal innovations,
culms terete, few-noded, the nodes and internodes densely lanate-
woolly; sheaths densely woolly, or the lower ones becoming glabrous
and shining on the back at maturity, striate, many-nerved, the lower-
most yellow, reduced to scales, the other ones shorter than the internodes,
tight and terete, densely woolly all over, ligules, auricles and collar
woolly-pubescent; blades erect, convolute, filiform but firm and pungent,
lanate-woolly al over, except at the summit, 10 cm long and about
»/., mm. wide when inrolled, the old ones becoming glabrous beneath
and scabrous on the uppei- surface; panicle scarcely exserted, the
peduncle lanate, rather depauperate bearing about 5-0 large spikelets
or not rarely but 1—2 flowers, axis of panicle woolly or becoming
more or less glabrous, the branches binate or solitary, bearing but one
long-pedicelled spikelet, the lateral spikelets with a shorter pedicel,
the^others with a pedicel as long as the glumes, the tips of the pedicels
clavate and densely woolly; spikelets erect, white-woolly, becoming
yellow and more or less glabrous at maturity, glumes very unequal,
the lower longer than the upper, narrowly lanceolate, subulate-acu-
minate but with erose or denticulate, obtuse tips, shortly mucronate,
densely lanate below, more or less glabrescent in upper half, lower
one 9-11-nerved, 4-5 cm. long, upper one 7-nerved, 3-31/2 cm. long,
lemma lanceolate-oblong, glabrous, including the callus 10 mm. long,
the densely hairy, 3-4 mm, long callus with a very acute naked point,
column firm, glabrous, slightly twisted, about 2—21/2 cm. long; central
^^vn 7—10 cm. long, naked only at the very base for 1—1\'/a cm,,
densely plumose with erectly spreading feathers and a scabrous naked
exserted tip of about 1 cm. long, lateral awns 5-7 cm. long, thin,
scabrous and more or less plumose at the middle. Asiatic Russia:

Caespitose ei-ect or ascending perennial from a thick rootstock, 40 cm.
or more high, innovations ititravaginal and probably also extravaginal,
with leafless scales at the base of the flowering culms, internodes
terete, striate, densely woolly-tomentose, the upper ones becoming more
01-less glabrous afterwards, nodes few, pubescent or becoming glabrous;
sheaths striate, tight, shorter than the internodes, densely covered with
white wool or the upper ones glabrescent, ligules, auricles and collar

woolly; blades rigid, striate, Hat below or somewhat complicate, inrolled
upwards, somewhat curved, lanate-woolly on both surfaces, glabrescent
in upper part; panicle shortly exserted or sheathed by the^\'uppermost
leaf, rather lax but contracted, axis terete, striate, glabrous or here
and there with a few hairs, branches subsolitary, densely lanate in
the axils, the longer ones 5-O-llowered, the shorter ones I—2-flowei\'ed,
not rarely all the branches bearing but one tlower, the branchlels
and pedicels striate, glabrous or slightly pubescent or with a few long
hairs, the pedicels with a glabi-ous or slightly pubescent clavate tipquot;^
spikelets erect, the lateral ones I\'ather shortly pedicelled, the other
ones with a pedicel nearly ns long as the glumes, lower glume glabrous,
9-nerved, linear-lanceolate, obtuse, erosely dentate at the apex, about
31/2 cm. long, upper glume slightly narrower about ^V. cm\', long,
5-nerved, glabrous, erosely dentate or .subbilid at the apex with a
mucro; lemma smooth, including the callus 10 mm. long, the densely
bearded, very acute, pungent callus about 3 mm. long, column smooth,
spirally contorted, up to 3 cm. long, awns very long, the central one

the tip naked and adpressed-hairy or scabrous, lateral awns shorter\'
4-472 cm. long, naked below, shortly plumose in upper part, the tip
riaked and scabrous. AfTghanistan..............

Geniculately ascending, densely caespitose perennial with long tomentose
roots and a more or less developed rootstock, 20—50 cm. high, including
the panicle, branched from the base and from the lower culm-nodes,
with intravaginal innovations and probably also with extravaginal ones;
culms terete, shorter than the internodes, densely lanate and woolly,
the upper ones puberulous only or quite glabrous, 5 - 6-noded or in
small specimens 2-3-noded, the nodes glabrous and often geniculate;
sheaths glabrous, striate, terete or slightly compressed, with broad
hyaline margins, tight or more or less slipping from the stems, the
lower sheaths often reduced to lealless scales and somewhat villous
along the margins, ligules a long-ciliate membi\'ane, auricles woolly or
bearded, collar woolly, the upper sheaths with ciliolate auricles and
glabrous collar; blades narrow, convolute, more or less curved or
tlexuous, acute, narrowed into a setaceous somewhat pungent tip, up
to 10 cm. long, about V2 wide when inrolled, glabrous or slightly
scaberulous beneath, densely hirtellous or scabrous on the upper surface,
margins not thickened; panicle up to 10 cm. long, more or less con-
ti\'acled, cuneate at the base and V-shaped in outline, sheathed by the

uppermost leaf, about 3 cm. wide at the summit, tlie peduncle very
short, axis striate, compressed, scaberulous, branches binate, shortly
pedicelled, spikelets bearing nearly from the base, the axils more or
less pubescent or pilose, the longer branches including the awns up
to 7 cm. long, 7—8-llowered, the shorter ones 4-5 cm. long or shortei\',
\'2—3-tlowered, the branches and spikelets erect and adpressed, the
pedicels shorter than the glumes or the laleral s|)ikelets neai\'ly sessile,
pedicels pubescent, chivnte at the tips, compressed, more or less late-
rally boardiMl ; spikelels yellowish, lower glume 11 12 mm. long, 3-nerved,
the latei-al nerves half as long as the midnerve, scabrous on the keel
and sonietinies more or less puberidous on the back, rather obtuse
or erosp with a short awn or mucro, the upper one about 15 mm. long,
3-nerved, the short lateral nerves close to the midnerve, obtuse at the
apex; lemma with the callus 5 - (5 mm. long, smooth and shining, the
very acute, pungent callus adpressedly hairy below, the hairs at the
summit longer, abcut 2 mm. long or slightly longer, the articulation
somewhat oblique, column straight, not twisted, about 4-5 mm. long;
awns erect or the central one,somewhat spreading, the latter up to 31/2 cm.
long, naked in lower 1/1- part, plumose upwards, the very tip adpre.s-
sed-pubescent or naked, plumose part of the awn very obtuse in outline,
lateral awns shorter, up to 2V2 cm- long, naked in lower half part,
bearded above the middle with long exserted naked or scaberulous tips.

Compactly caespito.-e glabrous perennial, culms simple or scarcely bran-
ched fVom the base, siciidei\', striate, erect, up to (30 cm. high, wiiy, smooth
or minutely scaberulous. 1—2-noded; sheaths firm, tight, glabrous and
smooth or slightly scaberulous with here and there a few long hairs,
more or less striate, not rarely puridish, shorter than the internodes,
ligule a ciliate membrane, auricles cihate or densely bearded, collar
smooth; blades setaceously convolute or filiform, acute up to 30 cm.
or more long, sometimes very long and overtopping the panicle, rather
Hrm, more or less llexuous. smooth beneath, scabrous or hispidulous
on the up|)er surface; panicles erect or somewhat nodding, more or
less contracted or rather loose and elluse, often secund, up to 30 cm.

7. All the awns of equal length or the central one a little longer than the
lateral ones................ °

Awns very unequal, the central one about 2 cm. long, sometimes somewhat
longer, twice as long as the lateral ones.

Rather robust laxly caespitose nearly 1 meter high perennial, innovations
so far as observed intravaginal, extravaginal innovations probably also
present, culms simple or scarcely branched from the base, 2 mm.
thick, 3—4-noded, nodes equally distributed, terete, glabrous and
smooth, minutely striate, only slightly compressed and iurrowed just
below the nodes; lower sheaths distichous and tlabellate oi-ovei\'lapping,
gaping, yellow, striate, giab lous, I\'ounded at the back, 5—6 cm. Ion«\'
the keeled prophyllum more or less pubescent, the hyaline marains ot
the sheaths sometimes minutely hairy, upper sheaths much longer, up
to 15 cm. long, tight, terete, striate, glabrous or slightly pubescent
on the margins above, scaberulous between the nerves, shorter than
the internodes, ligule a scarcely ciliolate rim, auricles thickened,
j)ubescent, or with a few long hairs, collar smooth, auricles of
the innovations strongly developed, densely bearded with spreadino-
hairs; culm-blades very firm, almost junciform, the lower ones up
to 8 cm. long, the upper ones up to 40 cm. long, narrowly con-
volute, glaucous, glabrous and smooth beneath, scabrous on the
upper surface with many bands of sclerenchyma. up to 2 mm.
wide when flattened after being treated with lactic acid, narrowed
into a pungent tip, blades of innovations shorter, the margins more
conspicuously pubescent above; panicle sheathed at the base by the
uppermost leaf, at least up to 30 cm, long, rather narrow, scarcely
1 cm, wide, contracted but not very dense or spike-like, axis subterete.
deeply striate or grooved, glabi\'ous, angulous above, branches solitary,
divided or tripartite just above the base, the longer ones 0-8 cm,
long, -10—;2—flowered, naked at the base, the sliorter ones lew-flowered,
all the branches and branchlets strictly erect and adpi\'essed, more or
less scaberulous, pedicels subclavate, shorter or slightly longer than
the glumes; spikelets erect, yellow, glumes with an inverse position,
scabrous or shortly pilose between the nerves, the lower 3-nerved or
sub-5-nerved, rather abruptly nan-owed into the short awn, scabrous
on the keel, 16 mm. long, the upper one 3 nerved, lateral nerves half
as long as the midnerve, the keel scabrous upwards, 14 mm. long, tip
subacute or truncate with a mucro; lemma glabrous, including the
hairy, subacute callus and the very short colurnti, 8—9 mm. long; awns
strictly erect, the central one densely long-plumose, especially above,
feathers spreading, obtuse in outline, without naked tips, the lateral
ones more adpressedly plumose, up to 10 mm. long. South West

l\\\'inicle loose and open, mostly not over 20 cm. long, sometimes somewhat
contracted but never dense and spike-like; blades 30 cm. long or mostly

Panicle dense and spike-like, up to 30 cm. long; blades very long, up to
40 cm., overtopping the panicle.

Very robust, tall and stilf perennial plant more than 1 meter high,
with much branched vigourous rhizomes, sending out subterranean
branches in all directions, with scale-like leaves and fibrous roots at
the nodes culms rigid, glabrous, fasciculately branched, the branche,
strictly erect; sheaths long, longer than the internodes, tight, striate,
glabrous, the lower ones merely short scales, yellow, quite glabrous,
lioule a very short ciliolate rim, auricles pubescent or nearly glabrous;
bFades veiy rigid, thick, stiflly erect, 25-40 cm. long or commonly
much longer, involute or complicate, junciform, very acute and pungent,
quite terete, smooth beneath, hirtellous and scabrous on the upper
surface, many-nerved, the margins not thickened, llattened out up to
5 mm. wide at the base; panicle shorter than the blades, narrow,
densely spiciform, iO-30 cm. long, about 1—2 cm. broad at the base,
with short branches, divided and spikelet-bearing nearly from the base
or the lower branches up to 5 cm. long, adpressed and more or less
naked at the base; spikelets densely congested, yellowish, glumes quite
smooth, slightly unequal, subobtuse or acutish, the lower 3-nerved,
\' 11 mm\', long, the upper 1-nerved, 12 mm. long; lemma punctulateor
smooth, including the very acute, pungent, cin-ved callus about 5-G mm.
lorif, the I\'/amm. long callus densely bearded especially above, the
hairs long, much surpassing the base of the lemma, column very short,
a scarcely 1 mm. long beak otily; awns about equal, 8—10 mm. long,
the central one commonly slightly longer than the lateral ones, densely
plumose to the very tips, acutish in outline, branching-point of awns
produced into 2 tliin, hairy appendages, bearing at the subobtuse tip a
pencil of hairs. A very remarkable species, resembling the Ammophila
of the downs, especially as to the vegetative parts. South West Africa:

9. Articulation between lemma and awns not oblique, margins of the lemma
not united with the .short column by a membrane; leaves always rather

lemma and the short column, the margins of the lemma united with
the base of the awns by a hyaline membrane; leaves mostly flaccid
rarely stilf and pungent.nbsp;\'

Rather robust erect perennial, including the panicle up to 50 cm. lone
with a much branched more or less creeping rootstock, culms erecT
Fasciculately branched at the base or sometimes simple, few-noded\'
terete, quite smooth, sheathed all along; sheaths longer than the
internodes, tight, terete or slightly compressed, striate, the lower ones
more or less gaping, distinctly scabrous nearly all over (very
characteristic!), with hyaline margins; ligule a ciliate membrane
auricles shortly but densely bearded; blades flaccid, acute not pungent\',
or rarely pungent and rigid in one vai\'iety, more than \'20 cm. k)nlt;r,\'
(lat below, more or less inrolled or convolute above, not rarefy
divaricately spreading, scabrous on both surfaces, ro\'ugh like the
slieaths, the upper surface hirtellous, the margins not thickened
2—3 mm. wide when expanded, ending in a long fine setaceous point,\'
more or less glaucous; panicle shortly exserted or sheathed by the
uppermost leaf, erect, at first somewhat contracted, very elfuse,
commonly more than 20 cm. lung, up to 15 cm. broad, rhachis glabrous\',
angulous or subterete and striate, the branches thin, elongate, sub-
flexuous, solitary but divided nearly immediately above the base
trichotomous or tripartite, reiterately branched, spreading or the
branchlets ascending, axils naked or slightly bearded, the branchlets
and pedicels shghtly scabrous, the pedicels commonly much lonaei-
than the glumes; spikelets yellow, glumes unequal with an inverse
position, both acute or acuminate, more or less erose at the apex, witii
a mucro, glabrous or scabrous, the lower 5-nerved, 16 mm. long, the
upper 3-nerved, 13-14 mm. long, sometimes the glumes are much
shorter; lemma including the callus 5—6 mm. long, with broad margins,
strongly keeled, 3-nerved, base cordate, suddenly contracted into\'\'the
oblique, sharp-pointed, laterally bearded, i-Vj, mm. long callus,
column very short, awns densely plumose with long spreading feathers,
tips obtuse or acute with a naked exserted scabrous point, the awns
equal or somewhat unequal, 10—15 mm. long. European Russia (Caspian

Blades short, not over 10 cm. long, mostly shorter, divergent,
very rigid and convolute throughout, pungent, culms 10—15 cm.
high, densely fascicled, the panicle very short, 5—6 cm. long,
more contracted, few-flowered, glumes 13 and 12 mm. long,
scaberulous, awns feathery with a naked scabrous exserted

Blades much longer, mostly up to 20 cm. long or longer, divergent
. not rigid, llaccid, flat at the base or in the lower half part,
acuminate but not pungent.

Awns feathery to the very tips, with long liairs of nearly
equal length, very obtuse in outline, glumes glabrous, smooth,
the lower 16 mm., the upper about 13 mm. long, awns up
to 11 mm. long. South East Russia to Soongaria ....
................var. typica Henr.

Awns not feathery all over, the tips naked, plumose part
acute in outline, glumes scabrous all over.

Lower glume 12—13 mm., upper one 10—11 mm.
long, awns of the lemma about 10—11 mm. long,
plant not very I\'obust, with shorter culms.

Awns very long, up to 15 mm. long or slightly
longer. Transcaspia to Turkestan. . . .
.....var. Kareliiii Trin. et lliipr.

Somewhat sulfrutescent stoloniferous much branched glabrous perennial,
culms erect, up to 60 cm. long or much longer, smooth, terete; sheaths
terete, striate, glabrous or minutely scaberulous only, longer than the
internodes, the lower ones not rarely purplish, the upper ones yellow,
ligule a densely ciliate rim, auricles shortly bearded; blades stilf and
rigid sometimes curved or flexuous, convolute throughout, very pungent,
15 cm. long or much longer, glabrous beneath, hirtellous or pubescent
on the upper surface, about 1 mm. wide when inrolled; panicle effuse,
oblong, strictly erect or slightly nodding at the summit, rather few-
flowered up to 15 cm. long, exserted, with solitary erectly spreading

branches, divided nearly from the base, reiterately branched axils of
panicle and main-branches much thickened, quite glabrous and smooth
branchlets and pedicels nearly glabrous and smooth, the pedicels very
long, clavate at the tips, sometimes more or less curved and flexuous
longer than the glumes; spikelets yellow, sohtary, glabrous, lower olume
5-nerved, l8-?0 mm. long, the upper one 3-nerved, 15—10 mmJono-
both linear-lanceolate, acute or acuminate, subobtuse or slightly awned\'
tips very scrabi-ous or not rarely somewhat ciliolate or pubescent\'
lemma tubulous mostly compressed and slightly narrowed above, in-
cluding the callus 7-8 mm. long, smooth, the callus broadly coiiical,
abruptly acuminate, very acute, almost glabrous, columtr about 1 mm!
long, straight, awns densely plumose tn the lips, not exserted, about
equal, up to 10 mm. long, the plumose pai\'t acute in outline\' E^vot
to Syria...........:........\'

11. Panicles with bearded axils; glumes distinctly awned, pedicels pubescent.
Glabrous sulfrutescent branched perennial, agreeing in the venetative
characters with Arutida scoparia, the sheaths and ligules quiTe as in
that species, the blades however strictly erect or but sliglitly spi-eadino\'
stilT and subulate, not curved or tlexuous; panicle not ell\'use. lanceolate--
ovate or oblong, strictly erect, rather dense, up to 15 cm. Ion«- 4—5
cm, broad, cuneate at the base and more or less sheathed by the
up[)ermost leaf, branches strictly erect or slightly spreading, solitary
but divided nearly from the base, axis of panicle, branches and branchlets
more or less pubescent, lower branches up to 7 cm. long, the other
ones gradually becoming shorter, all the branches many-flowered the
pedicels as long as or much shortei\' than the glumes, with clavate ti[)s-
spikelets yellow, adpressed and somewhat congested, glumes subequal
or somewhat unequal, the lower 9 mm, long, broadly lanceolate
suddenly contracted at the apex into a 1^2 mm. long awn, the U[)per
one 10—1! mm, long, lanceolate, erosely dentate at the summit with
a 1 mm, long awn from the sinus, both glumes 1-nerved or not rarely
with very short basal additional sidenerves, the keels scabrous especially
above; lemma including the callus up to 5 mm, long with a very short
straight not twisted column, the callus nearly smooth, oblique, scarcely
1 mm, long; awns about equal, long-plumose, about 10 mm. Ionquot;-
feathery nearly to the tips, with a minute naked exserted point, acute
in outline, Egypt...................

a very short awn or mucro, pedicels glabrous or scaberulous.
Glabrous, suffrutescent. branched perennial with long, oblique rhizomes
as in J. scoparia and A vulnerans\\ culms up to I meter high or much
longer, glabrous and smooth; sheaths smooth or scaberulous, longer
tlian the internodes, ligules and aui\'icles as in A. scoparia, blades very
rigid, subulate, very acute and |)ungent, 10-30 cm. long or slightly
shorter than iO cm, smooth beneath, scabrous or hirtellous. on the
upper surface; panicle not so dense as in A.nbsp;linear-ovate,

usually interrupted and more or less loose, sometimes rather depaupe-
rate or more than 20 cm. long, axis striate, subcompressed, glabrous,
branches solitary, much divided fi\'om the base, the lower ones semi-
whorled in robust specimens, naked in the lower part, up to 10 cm.
long, ascending or somewhat spreading, the upper branches gradually
becoming shorter, branches and brancnlets nearly smooth, pedicels
clavate, adpressed-hairy above, mostly strictly erect or somewhat
spreading or flexuous, those of the latei\'al spikelets much shorter than
the glumes; spikelets yellow, glumes nearly glabrous on the keels,
somewhat unequal, the lower 13 mm. long, gradually narrowed into
a short awn, with a strong midnerve and more or less developed
additional short sidenerves and sometimes sub-5-nerved, upper glume
14—15 mm, long with an ei\'osely dentate or bifid summit and a very
short awn from the sinus, 1-nerved or sometimes sub-3-nerved; lemma
as in A. vulnerans, strongly S-nerved, the callus nearly glabrous or
slightly hairy; awns nearly equal, the lateral about 12 mm, long, the
central one slightly longer or up to 15 mm. long, densely plumose
with excurrent naked tips, the plumose part acute in outhne. Africa:
From Nubia and Egy[)t to Tunis and Algeria, with a subspecies in

Sheaths except the lowermost ones adpressedly pubescent, blades
more or less densely pubescent on both surfaces. Algeria. .
. . . ............var. pubescoiis Kenr.

Blades much shorter than in the North African plants, only
1 \'/2—^ cm. long, divaricate; panicle elegant, with much thinner
llexuous or curved branches and pedicels; glumes narrower,
the lower one more obtuse, both very distinctly ciliolate on
the keel above. South Africa: Great Namaqualand ....
. . . ............subsp. I\'eyeri Heiir.

12.nbsp;Internodes at least the lower ones densely lanate-woolly, or if not woolly

Internodes quite glabrous or scaberulous only, sometimes with a minute
or very scanty pubescence................

upper ones sometimes with a short pubescence or glabrous .... 14.
Sheaths quite glabrous, the lower sometimes scabrous or with a scanty

Laxly caespitose perennial with a suffrutescent, thick, ascending oi\'
creeping rhizome, with extravaginal innovations, covered with old scales,
culms simple, terete, slightly striate, erect or geniculate, elegant, 2-noded,
the nodes glabrous, together with the panicle up to 20 cm. high,
internodes densely tomentose or woolly, the uppermost internode
glabrous; sheaths tight, shorter than the internodes, the lower ones
with white hyaline margins, all the sheaths and scales woolly or the
uppermost one glabescent, ligule a densely woolly rim, auricles with
a Hake of wool, collar pubescent; blades rigid, convolute, curved, quite
lanate-tomentose, narrow, scarcely 1 mm. wide when expanded,
2—3 cm. long, pungent; panicle exserted, narrow but rather lax, axis
angulous, scabrous, branches binate or solitary upwards, scaberulous,
branchlets 1—3-flowered, pedicels very scabrous with a tuft of longer
hairs at the subclavate tip; spikelets erect, adpressed, violaceous or
purplish-brown, glumes unequal, the lower with hyaline margins, pilose
on the middle, scabrous on the keel, 3-nerved, lateral nerves shorter
than the midnerve, acute, not awned, about 14 mm. long, the upper
one distinctly 3-nerved, the nerves approximate and about equal,
percurrent, glabrous and smooth on the keel, acuminate, about 18 mm.
long; lemma very smooth with a very acute pungent densely bearded
2 mm. long callus, the hairs reaching nearly half the length of the
lemma, which is about 5 mm. long, column elegant, straight, quite
glabrous, not twisted, 6—7 mm. long, awns unequal, the central one
spreading, up to 35 mm. long, long-feathery nearly from the base,
the lower part less feathery and pilose only or quite naked only at
the very base, with a slightly excurrent tip, acute in outline, lateral
awns very thin, glabrous, much shorter, up to 15 mm. long. North

Sheaths woolly, the upper ones always glabrous; blades glabrous or scabrous
not with a densely woolly tomentum.

Densely caespitose erect or ascending perennial with a short, not
creeping rootstock, culms erect or geniculately ascending, simple or
somewhat branched from the upper nodes, dwarf or up to 30 cm.
high, terete, woolly, 2—3-noded, the nodes glabrous, upper part of the
culms shortly hairy or quite glabrous; lower sheaths scale-like with
reduced very short blades, striate, somewhat keeled, with a fugacious
wool, the following more or less lanate, mostly soon becoming more
or less glabrous, the upper ones glabrous and smooth throughout,
ligule a ciliolate rim or a tlake of wool, auricles densely, bearded,
those of the innovations very woolly, those of the upper leaves shortly
bearded or ciliate only, collar glabrous; sheaths shorter than the
internodes, the latter sometimes slightly tomentose or pubescent only,
blades narrowly convolute, stilf but not very rigid, with a pungent
tip, slightly curved, scarcely 1 mm. wide when expanded, up to 10 cm.
long, mostly shorter, glabrous or slightly scabrous beneath, scabrous-
hirtellous on the upper surface; panicle strictly erect, lanceolate in
outline, rather loose but narrow, mostly sheathed by the uppermost
leaf, the sheaths of the latter with a well-developed more than 3 cm.
long, bicarinate, many-nerved ciliolate prophyllum; panicles including
the awns up to 15 cm long, axis striate angulous more or less scabrous,
branches binate, one up to 7 cm. long, including the spikelets, many-
flowered, naked at the base, sti\'ictly erect, the other 3—4 cm. long,
branched from the base, 2—4-llowered, strictly erect and adpressed,
the branches somewhat distant, gradually becoming shorter upwards,
branchlets and pedicels scaberulous. the latter with a subclavate more
or less pubescent or hairy tip, sometimes laterally bearded or with
a collar of long hairs, the pedicels of the lateral spikelets shorter the
other ones longer than the glumes; spikelets greenish or yellowish,
sometimes tinged with purple, glumes unequal, lanceolate, the lower
mostly 15 mm. long, sub-3-nerved, the lateral nerves shorter, glabrous
or sometimes with a short pubescence, scabrous on the keel, obtuse,
the upper one narrower, 1-nerved, up to 18 mm. long, glabrous,
sometimes with scattered long hairs; lemma with a densely hairy,
very acute, 2 mm. long callus, the hairs surpassuig the true base of
the lemma but not reaching the middle, 0—7 mm. long, column up
to 10 mm. long, straight, not twisted, glabrous; central awn mostly
with a naked tip, 41/2—5 cm. long, naked below, lateral awns about
2 cm. long, nearly smooth. From the Algerian Sahara to Egypt, Nubia
Palestine and Arabia, Armenia, Persia, Turkestan to western Tibet .
..................Aristida pliimosa L,

Central awn with long, spreading hairs, plumose to the very tip,
the feathery part rounded and more or less obtuse in outline,
naked only at the base, the naked part sometimes adpressed-
pubescent and commonly only 7 mm, long; plant more or less
glaucous, ligules long-ciliate, panicles linear-oblong, finally some-
what exserted, lower glume 16 mm., upper one 20 mm. long,
lemma including the callus 6—7 mm. long, column 9—10 mm.
long, central awn 5 cm. long, the lateral ones about half as
long. Aderbeischan.................

Central awn with more or less spreading or ascending hairs, tip
of awn exserted, naked, adpressed-pubescent or scabrous, naked
basal part of the central aAvn at least 1/5 the length of the
whole awn.

Internodes not tomentose or lanate, with a characteristic dense
and short pubescence only, lemma including the callus 5 mm.
long, the column about 10 mm. long, lateral awns 15—i8 mm.
long, the central one naked in lower half pai\'t, 4 cm. lono-.

Internodes at least the lower ones densely tomentose or lanate.
Upper glume remotely rather long-ciliate or hairy above,
especially along the margins, glabrous at the Imse and
summit; pedicels pubescent, without a lateral tuft of hairs
at the tips, feathers of central awn longer and more
spreading than in typical A. plumosa. Southern Persia,
...........var. Haussknechtii Boiss.

Upper glume glabrous or scabrous, without long hairs.
Pedicels densely pubescent, densely ciliate at the sub-
clavate tips with a collar of longer hairs, surrounding
the base of the glumes; plants yellow, culms much
branched and geniculate, panicles not exserted,
ligules shortly ciliate, lower glume 14 mm., upper
18 mm, long, lemma including the callus 5 mm, long,
column 7-8 mm, long, lateral awns about 18 mm.,
the central one 41/3 cm. long, tlie naked lower part
15 mm, long, the naked tips up to 3 mm, long,

Pedicels scabrous or minutely pubescent, tips slightly
clavate and pilose with a lateral tuft of hairs, but
not with long hairs as a collar at the base of the glumes.
Lower glume remotely adpressed-pilose, especi-
ally on the margins, glabrous on the back and
at te summit; pedicels with a lateral tuft of
bail\'s, lemma including the callus 4—6 mm. long,
column about 5 mm. long, central awn naked
in lower half part, the exserted naked tip about

Lower glume without long hairs, glabrous or
scabrous only.
Central awn with shorter, more adpressed-
plumose feathers, the lower half part naked,
column of awns about 5 mm long; other
characters as in the type. Egypt ....
. . . . . var. seminuda Trin. et Rupr.

Central awn with long, more or less spreading
feathers, naked only in lower 1/3 or I /5 part.
Central awn naked in lower 1/5 part, the
pedicels with a lateriil tuft of hairs, the
central awn with a naked excurrent tip.

Centra] awn naked in lowerl/3 part, pedicels
and central awn as in the preceding

and lower internodes, is common in Algeria and Tunis. . .
.............var. iloccosii Duraud ot Scliinz.

Central awn plumose to the summit, bearing feathers of nearly equal length,
the feathery part very obtuse in outline.

from most of the nodes, innovations few, at flowering time nearly
wanting, culms erect or geniculate-ascending, terete, striate, with
densely scabrid-pubescent internodes, up to 25 cm. high ; sheaths longer
than the internodes, striate, scaberulous, especially between the
nerves, shghtly compressed, gaping at the summit, ligule a densely
ciliate rim, auricles ciliate; blades striate, up to 15 cm. long, or the
lower much shorter, the lowermost ones scale-like with reduced blades,
involute, filiform, more or less curved, ending in a long setaceous point,
scabrous beneath, hirtellous on the upper surface; inflorescence sheathed
by the uppermost leaf, oblong or linear-lanceolate, lax, 12—15 cm.
long, composed of spurious leafy or spathaceous panicles with well-
developed up to 3 cm. long prophylla, axis of panicle rather thin,
compressed, scaberulous, branches binate, with scabrous branchlets and
pedicels, erect or ascending, naked at the base, the longer ones up to 8 cm,
long, the others up to 5 cm. long, all rather few-fiowered, lateral pedicels
shorter than the glumes, with subclavate pubescent tips; spikelets
yellow, erect, distant,glumesaboutequal,theloweracuminate,8mm. long,
scabrous on back and keel, with hyaline margins, 3-nerved, the upper one
9 mm. long, nearly glabrous with a distinctly bifid apex and a mucro from
the sinus, 1-nerved;lemma including the callus about 5 mm. long, smooth,
the very acute, densely hairy callus 2 mm. long, the long hairs much sur-
passing the base of the lemma, column short, scarcely 1 mm. long, central
awn naked below, plumose in upper half, 13—15 mm. long, erect, lateral
awns very thin, glabrous, about half as long as the central one. Libia
.................Aristida Zittelii Aschers.

Panicle more dilfuse ad open, branchlets and pedicels
thinner and longer than in the type, lower glume
densely shortly pubescent, more or less ciliate on the
keel and along the margins below. Algeria .....
............var. algeriensis Hour.

Central awn naked at the base; column of awns short or nearly wanting,
never twisted; lower glume shorter than te upper one......

17.nbsp;Central awn about as long as the lateral ones, scarcely 1 cm. long, erect,

the plumose part obtuse in outline; column of awns very short but
twisted, not exserted above the glumes; callus broadly conical with
an acute naked point, shortly pubescent all over with a collar of long
haii\'S at the base of the lemma.

Branched, slender and elegant erect, caespitose or more or less
creeping, glaucous perennial, without sterile innovations at the
ilowering time; culms including the panicles up to 80 cm. high,
simple or commonly more or less branched, terete, striate, densely
pubescent, nodes glabrous; sheaths shorter than the internodes, striate,
compressed, scaberulous, ligule a ciliolate rim, auricles ciliate; blades
10—15 cm. long, narrow, setaceous, fdiform, llaccid, more or less curved,
narrowed into aline point, not pungent, scaberulous beneath, hirtellous
on the upper surface; inflorescence more or less composed of spurious
leafy panicles, not rarely more exserted, linear-lanceolate, 10-20 cm.
long, sometimes still longer, axis of panicle scabrous, subterete or
late\'i\'ally sulcate, with distant erect solitary branches, the axils bearded
or distinctly ciliate, branches up to 7 cm. long, gradually becoming
shorter, many-flowered, divided from the base, adpressed, reiterately
branched with scaberulous branchlets and pedicels, the latter slightly
compressed and subclavate; spikelets erect and adpressed, yellowish-
o-reen «lumes about equal, lanceolate or oblong-lanceolate, acuminate,
the lower 8 mm. long, 1-nerved, minutely pubescent on back and keel,
the upper one 7 mm. long, nearly glabrous, minutely scaberulous on
the keel, 3-nerved; lemma smooth, together with the very characte-
ristic callus and the about 2 mm. long column, about 8 mm. long;
central awn scarcely 10 mm. long, erect, the lateral ones spreading,
glabrous and about 8 mm. long. North Africa: Algerian Sahara. . .
...........Aristida brachyathera Coss. et Balansa

Central awn much longer than the lateral ones, up to 5 cm. long or longer,
spreading, the plumose part acute in outline; column of awns about
10 mm. long, scarcely twisted, exserted above the glumes; callus narrowly
conical with an acute naked point, densely hairy along the margins.
Laxly caespitose almost sulfrutescent erect perennial with a much
branched rootstock, innovations intra- and extravaginal; culms erect
or more or less ascending, 3—4-noded, nodes constricted and glabrous,
lowermost internode always tomentose, upper ones more or less pubescent,
except a small portion below each node, uppermost one scaberulous
only, sheaths tight, striate, terete the old ones gaping, scaberulous or
becoming smooth, shorter than the internodes, ligule a densely ciliate
membrane, auricles densely bearded, collar smooth; blades narrow,
convolute throughout, curved, pointed, 7—8 cm. long or mostly shorter,
those of the innovations much shorter and only a few cm. long, strongly
nerved, scaberulous beneath, hirtellous on the upper surface; panicle
shortly exserted or moi-e or less sheathed by the uppermost leaf but
not composed of spurious panicles, simple, erect, narrowly linear or

lanceolate, together with the spikelets 10-15 cm. long, axis, branchlets
and pedicels scaberulous, branches binate, bipartite\'nearly from the
base, bearing few ei-ect or adpressed spikelets, axils not bearded or
ciliate, sometimes pubescent; spikelets yellow, not rarely tinged
with purple, glumes glabrous, linear-lanceolate, acuminate, the lower
3-nerved, 15-16 mm. long, scaberulous on the keel, the upper one
1-nerved or with an additional sidenerve, 13 mm. long, keel smooth ; lemma
including the callus 4 mm. long, the body smooth below, very distinctly
scabrous in upper part, the densely bearded callus about 1 mm. long,
central awn plumose from the brancliing-point of the 3 awns, the
lateral ones naked, 15-16 mm. long. Egypt and Sinai to southern Pei\'sia.
•.....................Aristida Iladdiana Savi

18. Glumes not over 1 cm. long, the lower 8 mm., the. upper one 9 mm. Ion«\',
very acute, mostly shortly awned or the upper With a mucro or short
awn from a bifid apex, glabrous; lemma ovate-acuminate, column
nearly wanting or a scarcely mm. long beak; internodes pubescent
or sericeous, but not woolly.

Slender and elegant, caespitose or more or less stoloniferous perennial,
branched from the base and most of the lower nodes, culms erect or
geniculately ascending, terete, striate, few-noded, nodes nearly glabrous,
up to 40 cm. high including the panicles; sheaths mostly shorter than\'
the internodes, striate, more or less compressed with hyaline maroins
scaberulous, ligule and auricles ciliate; blades narrowly convotute\'\'
somewhat curved, 5—6 cm. long or sometimes much longer, those of

beneath, hirtellous on the upper surface; panicle linear, ovate-lanceolate
or pyramidal, lax, sheathed by the uppermost leaf or shortly exserted
the peduncle pubescent, the axis scaberulous, about 10 cm. Ionquot; or
somewhat longer, the lateral panicles mostly much shorter, branches
somewhat remote, the lower ones much divided from the base and
semi-whorled, many-flowered, the other ones bipartite, naked at the
base or the lateral ones subsessile and few-llowered, branchlets and
pedicels scaberulous, axils not bearded, glabrous or puberulous; spikelets
yellowish-green, glumes slightly unequal, the lower 1-nerved orsometimes
with very short lateral nerves, minutely scabrous on the keel, the upper
3-nerved, smooth; lemma smooth, 5 mm. long including the densely
hairy, acute, about 1 mm. long callus; central awn up to 15mm. long,
naked in lower half part, the tip excurrent, the feathery part veiy
obtuse in outline, lateral awns spreading, about half as long as the
central one. North Africa: Western Sahara to Nubia and Egypt.
.............Aristida acutiflora Trin. et Rupr.

Glumes more than i cm. long, the lower i2 mm., the upper one 13 mm.
long, very obtuse, unawned, witli erosely dentate tips, both scabrous
on the keels and more or less so on tbe back; lemma tubulous,
column short, 2—4 mm. long; internodes densely lanate-woolly, at
least the lower and middle ones.

Caespitose, more or less branched, dense or somewhat lax peren-
nial, commonly 20—30 cm. high, sometimes more than 40 cm.
long, culms erect or geniculately ascending, few-noded, the nodes
glabrous, the internodes densely woolly, the upermost one pubescent
only and grooved laterally; sheaths glabrous or more or less scabe-
rulous. tight oj- the lower slipping from the stems, slightly compressed,
striate, \\\\ith broad hyaline margins, shorter than the internodes,
hgule a ciliate rim, auricles ciliate or bearded, collar glabrous;
blades mostly up to 10 cm. long or in robust specimens not rarely
more than 15 cm. long, tliose of tbe sterile shoots much shorter
and only a lew cm. long, convolute-tiliform, acute, pointed but not
pungent, soft and llexuous; inllorescence narrow, 10—15 cm. long,
2-3 cm. broad, composed of spurious leafy panicles with 31/2 cm.
long, many-nerved ciliately keeled prophylla, axis of panicle hirtellous,
branches remote but adpressed, binate, the longer ones with a 1 cm. long
peduncle, up to 5 cm. long, including the spikelets, 5-7-llowered,
the sliorter ones about 3-llowere\'d, subsessile, gradually becoming
shorter upwards, pedicels very shoi-t, or if of .suflicient length shorter
than tlie glumes, pubescent or hairy and pilose at the subclavate tips,
axils of branches more or less pilose; spikelets yellowish-green, glumes
scabrous, both 3-nerved. the lateral nerves half as long as tbe keel and
close to the midnerve; lemma glabrous with the acute, densely hairy about
i mm. long callus, about 5 mm. long, scarcely narrowed into the straight
column; central awn up to 3 cm. long, naked in lower Vs part, feathery
part subobtuse in outline, the naked tip scabrous, lateral awns erect, up
to 15 mm. long. Africa: Northei-n part of Egy[)t and Nubia ....
................Aristida brachypoda Tausch

10. Glumes hirsute or pilose all over or sometimes glabrous only at the tips. 20.

20. Lemmas smooth, column of awns glabrous below the branching-point of tbe
awtis, central awn plumose to the very tip, very obtuse in outline;
glumes very hiisute; pei\'ennial plants............i2|.

I.emmas |)apillose-nuiricate, column of awns hairy below the branching-
point of the awns or rarely quite glaubrous, central awn with a naked.

glabrous or scabrous exserted tip; glumes shoi\'tly hairy or pubescent;
annual plants................................99

21. Innovations intravaginal with an alternation of short and lono-internodes •
leaves crowded near the base of the few-noded culms, which have also
very unequal internodes, alternately long and short, bringino-the leaves
together approximately in pairs, the lowest leaves shortly sheathed,
the uppermost subopposite with somewhat longer sheaths; column of
awns short, about 1^2 tnm. long, slightly twisted.
Almost sullrutescent densely caespitose perennial, branched from the
base, 15 cm. long or less, culms erect, slender, glabrous or hairy below
the panicle, terete, striate, internodes very unequal, the lowest short
and quite sheathed, the following long exserted, 5—10 cm. lono- the
next very short, scarcely 5 mm. long, the uppermost one slightly
longer and shortly exserted, nodes bearded or becoming glabrous
afterwards; sheaths tight, very short, about 5 mm. long, striate, o-labrous
with ciliate or slightly woolly margins, ligule a ciliolate rim, auricles
bearded, collar glaubrous; blades very short, almost rudimentary,
subulate, involute, subpungent, 3—10 mm. long, or very rarely lonoer
and somewhat curved, very rigid, more or less divaricately spreading-
smooth and striate below, pubescent on the upper surface; panicle not
rarely nodding, very short, spike-like and often secund; includino-the
awns up to 3 cm. long and about 1V2 cm. broad, rhachis hairy,
branches very short, branched from the base, hairy, pedicels short
almost sessile; spikelets crowded, yellowish-brown, tinged with purple,
glumes unequal, linear-lanceolate, acuminate, long-awned, the lower
11—12 mm. long, hirsute all over, manifestly 3-nerved, the upper one
16 ram. long, narrower, more or less glabrous at the base, very hirsute
above, 1-nerved or with one or very rarely two additional sidenerves,
tips of both glumes convolute and slightly bifid but the setulae very
inconspicuous; lemma 4-6 mm. long, including the acute densely
hairy sometimes more than 1 mm. long callus, the body of the lemma
smooth, minutely bilobed, pale or purplish; central awn spreading, up
to 3 cm. long, lower part shortly hairy, upper part long-feathery to
the very tip, obtuse in outline, lateral awns naked, up to 15 mm. long.

Innovations extravaginal, culms 4—5-noded. with nearly equal internodes,
blades not crowded near tlie base of the culms, the lowest reduced
to scales with rudimentary blades, the upper ones long-sheathed with
well-developed blades; column of awns 5 mm. long, not twisted.

Suffrutescent laxly caespitose perennial, witb a much branched thick
rhizome; culms elegant, erect, up to 30 cm. high, sbeathed all along-
simple, terete, only slightly striate. laterally sulcate, somewhat scaberu-
lous, nodes annular, densely bearded with long spreadmg white hairs;
sheaths much shorter than the internodes, slightly scabrous, terete,
tight, ligule a short ciliate rim, auricles densely divaricately bearded,
collar gTabrous; blades linear-lanceolate, acute, gradually narrowed
into a quot;setaceous point, more or less curved. Hat at the base and2-3
mm. wide, convolute upwards,nbsp;cm. long, many-nerved, the

margins not thickened, scaberulous beneath, pubescent or densely
hirtellous on the upper surface; panicle shortly exserted or sbeathed
by the uppermost leaf, more or less obovate, short, rather few-tlowered,
dense and subsecund or subfastigiate, dried, fan-shaped, without the
awns 4—5 cm. long or shorter, up to 2 cm. broad, axis striate, scabe-
rulous, branches\'scabrous, solitary, scarcely Vs cm. long, bearded in
the axils, very shortly peduncled with few (2-6) congested spikelets
on very short, hairy pedicels; spikelets greenish-white with a brownish
or dark base, densely hairy all over or the tips more or less glabrescent,
glumes unequal, 3-nerved, the lower 11-14 mm. long, acute, the upper
16-18 mm. long, acuminate, with a minutely bifid apex and inrolled
tips; lemma oblong, smooth, truncate, emarginate, bilobed at the apex,
5\'/o\'mm. long inclusive the 2 mm. long, densely hairy acute callus;
central awn 3V2 cm. long, feathery all over, tip obtuse in outline,
lateral ones naked up to 2 cm. long. South West Africa: Great

22. Panicle narrow, strictly erect,- contracted but not spike-like, somewhat
dense, up to 20 cm. long and up to 4 cm. broad, with short subsessile,
few-flowered branches; glumes unequal, obtuse, the lower one broadest,
3-nerved ; column of awns twisted; central awn sparingly hairy in lower
part or sometimes naked, densely bearded upwards, except the naked tip.
Compact, caespitose annual plant with fascicled erect glabrous 2—4-noded
culms, the nodes glabrous, up to 40 cm. high, internodes terete, striate,
slightly scabrous; sheaths shorter than the internodes, very striate,
scabrous, especially on the nerves, slightly compressed with broad
hyaline margins, ligule shortly ciliate, auricles long-bearded, collar
fdabrous; blades convolute, setaceous, thin and llaccid, 6—10 cm. long,
scarcely 1 nun. wide when expanded, narrowed into a fine point,
scaberuldiis beneath, hirtellous on the upper surface and with a few-
long hairs especially near the base; spikelets pale greenish or yellowish,
hirtellous, glumes subequal or somewhat unequal, the lower ovate-

lanceolate, 3-nerved, the lateral nerves about half as long as the midnerve
the summit of the glume rather suddenly contracted or truncate and
erose with a short mucro, the very tip of the glume smooth, ciliate
on the keel, up to 6 mm. long or slightly longer, the upper glume
narrower, ciliate on the keel and hairy on the back, the hyaline margins
and tips glabrescent, 3-nerved, the lateral nerves close to the midnerve,
the excurrent tip subobtuse or subacute, slightly bifid or emarginate
with a short awn from the sinus, up to 10 mm, long; lemma includino-
the callus about 4 mm, long, the column up to 10 mm. long, the body
of the lemma tuberculate-scabrous nearly all over, the callus very
curious with an oblique glabrous long and sharp point, and two collars
of hairs, one shortly hairy at the insertion of the glabrous point, the
other with long hairs at the base of the lemma and surroundin\'o\' it,
the lateral hairs reaching half the length of the lemma, column hairy
or sometimes naked or partly hairy, the hairs more or less spreading
or ascending, central awn up to 5 cm. long, feathery part obtuse in outline,
tip long, excurrent, the basal part of the awn sometimes more or less
naked or sparingly hairy, lateral awns naked, about 1 cm long, Egypt
and Sinai to Abyssinia and Eritrea, east to Arabia and British India
(The Panjab). Alsoin South West Africa: Hereroland and Damaraland.
.............. • Aristida hirtigluma Steudel

Panicle broad, erect, very elTuse and open, up to 30 cm, long and 20 cm.
wide, with long, erect-divaricate branches, divided nearly from the
base, bearing spikelets on long pedicels; glumes unequal, subacute, more
or less shoi-tly awned, the lower as broad as the upper, both 3-nerved
or not rarely sub-5-nerved, column of awns slightly twisted; central
awn equally plumose all over, except the naked tip, or sometimes
naked in lower part.

Elegant, erect, caespitose annual, including the panicle up to 1 meter
high, culms straw-coloured, erect, 4—5-noded, long-exserted, few in a
tuft, up to li/o mm, thick, terete, slightly striate, glabrous and conspi-
cuously scaberulous between the nerves; sheaths shorter than the
internodes, lower ones very short, laxly aggregate with short blades,
upper ones very long, tight or somewhat ga[)ing, subcompressed, striate
and asperulous, with glabrous nodes and hyaline margins, ligule a
short ciliolate rim, auricles more or less densely bearded, collar glabrous;
blades erect or more or less curved, narrow, plicate-convolute, sub-
(iliform, acuminate, asperulous beneath, hirtellous on the upper surface,
up to 20 cm. long and up to 2 mm. wide when flattened; panicle
elongate, lax, ovate in outline, axis terete, asperulous with glabrous
axils, branches thin, elongate, solitary, divided nearly from the base

and bi- or tripartite, erectly spreading witb scabrous branches and
pedicels, the lower ones up to 10 cm. long, spikelets long-pedicelled,
much longer than the glumes and not rarely up to 2 cm. long, glumes
hirtellous, scabrous and ciliate on the keels, the acutish tips glabrescent,
tbe lower one \'10 mm. long, the upper -11 mm. long, slightly bifid at
the apex with a short awn from the sinus; lemma including the callus
about 31/2 mm. long, black at maturity, glabrous below, more or less

hairy in upper half or sometimes glabrous, callus of nearly the same
shape as that of Aristida Mrtigluma but the hairs of the upper collar
moi\'e copious and slightly shorter, not reaching half the length of the
lemma, tbe lower collar with longer hairs, therefore the two collars
not so\'sharply separated as in A. hirtigliima-, central awn up to 4 cm.
lono- feathery part obtuse in outline, lateral awns naked, up to 10 mm.
lono! South West Africa: South Angola and Damaraland, east to Rhodesia.
..............Aristida gracilior Pilgor

Column naked, not bearded at the branching-point of the awns,
tbe central awn scabrous only in lower part, bearded in upper

[Aristida Mrtigluma is well to recognize in its northern range, but
is connected witb A gracilior by intermediary forms in South
West Africa, where A. gracilior is endemic, such intermediary
forms are probably hybrids between the two species].

Central awn feathery from the branching-point of the 3 awns, the tip
short, naked and exserted, column of awns strongly twisted, uj) to
15 mm. long.

Laxly caespitose or more or le.ss compact perennial, much-branched
and almost sulfrutescent at the base, innovations probably intra- and
exti-avaginal, culms erect and simple or sparingly branched at the very
base, up to 30 cm. high inclusive of the panicle, 2—4-noded, terete.

smooth, minutely striate or grooved laterally, nodes smooth; sheaths
tight, striate, glabrous and smooth, the lower ones reduced to straw-
coloured scales, the upper ones terete and shorter than the internodes
ligule a densely ciliate rim, auricles long-bearded, the hairs up to
2 mm. long, collar smooth; blades glaucous, narrow, up to 15 cm.
long, mostly reaching or overtopping the base of the panicle, thé
lower blades commonly shorter, convolute, expandedabout 1 mm. wide,
mostly curved or more or less ilexuous, linear-filiform, rather rigid\'
ending in a fine acute point, not pungent, glabrous and striate beneath,\'
hirtellous on te upper surface; panicle shortly exserted or not rarely
sheathed by the uppermost leaf, very narrow, linear-lanceolate, erect,
contracted but somewhat interrupted especially at the base, \'up to
10 cm. long and about 2 cm. wide, rhachis filifoi-m, terete, striate
shghtly scaberulous, branches solitary, divided nearly from the base!
rather short, strictly erect and adpressed. shortly peduncled, the [)edicels
much shorter than the glumes or the lateral ones subsessile, branchlets
and subclavate pedicels scaberulous, axils of panicle smooth; spikelets
erect, yellowish-green, glumes linear-lanceolate, glabrous, the lower
15 mm. long, subobtuse at the tip with a fine mucro, 3-nerved the
lateral nerves half as long as the midnerve and anastomosing, scabrous
on the keel only above, the upper one 13 mm. long, rather suddenly
acuminate from the middle, acutisli, slightly scaberulous above and
on the keel in upper part; lemma ovate-lanceolate, scaberulous or
tuberculate especially above, up to mm. long inclusive of the lone
hairy very acute callus, column scaberulous, strongly twisted ■ c.entral
awn up to 51/2 cm. long, feathery part obtuse in outline with a scabrous
excurrent tip, lateral ones erect up to cm. long. Soutliei\'n Arabia

Culms and panicles very short, totally hidden by the radical leaves, only
the bearded awns exserted above the tufts.

Compactly tufted up to 3 cm. high annual, inclusive of the very short
slender, 1-noded, slightly hairy culms and the very reduced panicles
forming small hemispheric cushions, scarcely 5 cm. in diameter; sheaths
glabrous, scabrous above with broad hyaline margins, the lowest reduced
to membranaceous scales, the upper strongly striate, ligule a small
ciliolate rim, auricles bearded, collar smooth; blades very short
setaceously convolute, about 1 cm. long, scarcely 1 mm. wide when
expanded, rather rigid, more or less curved, striate, ending in a fine
not pungent tip, scabrous on both surfaces or hirtellous on the upper

surface - panicle few-flowered, much reduced, contracted, with hispidulous
rhachis\'and branches, pedicels short, hispidulous or more or less pilose
especially at the subclavate tip; spikelets whitish, erect, glumes linear-
lanceolate, acuminate, both 3-nerved, tl.e lateral nerves about half as
long as the midnerve and slightly scabrous only on the keels above,
the lower up to iO mm., the upper one 8 mm. long; lemma with the
lono\'-hairy, very acute callus about 6 mm. long, lanceolate-ovate, quite
smooth, column of awns short, smooth, 2 mm. long, scarcely twisted,
slightly hairy or pubescent at the branching-point of the three awns;
central awn mostly purplish, the feathers yellowish-white, scaberulous
below, adpressedly plumose above the middle to the very tip, up to
21/2 cm. long, lateral awns very line, nearly i cm. long. Very
characteristic species. South West Africa: Namaqualand and Hereroland.

26. Culms naked, with one glabrous node at the middle, column of awns up
to 6 mm. long; central awn about 21/2 cm. long, lateral awns up to

Compact caespitose perennial, forming up to 5 cm. high, dense tufts
with numerous innovationshoots, culms exserted, very variable in
length, sometimes dwarf and only 5 cm. long or up to 30 cm. long,
incfusive of the panicle, very slender, geniculate at the node, glabrous,
slightly striate or smooth; lower sheaths short, firm and persistent,
olabrous, more or less w-oolly near the margins, with more or less
reduced blades, upper sheaths much shorter than the internode, tight,
striate, somewhat compressed-keeled with hyaline margins, ligule a
short ciliolate rim, auricles densely bearded, collar smooth; blades
setaceous, convolute, rigid, curved or llexuous, glaucous, striate, glabrous
and smooth or scaberulous beneath, minutely villous or hirtellous on
the upper surface, 11/2—^ cm. long, rarely up to 10 cm. long, scarcely
V2 mm. wide when expanded, ending in a very obtuse thickened tip;
panicle very narrow, erect, contracted but rather loose and interrupted
at the base, 2V2—terete or striate, glabrous or
scaberulous above, branches solitary, bipartite nearly from the base,
(iliforrn, strictly erect or somewhat spreading with scaberulous
branchlets and pedicels, axils not bearded, lateral pedicels short,
always shorter than the glumes; spikelets yellow, sometimes tinged
with purple or with a dark spot at the base, glumes nearly equal,
scaberulous on the back, the lower lanceolate, obtuse, 3-nerved,
scabrous on the keel, the upper narrower and less obtuse, 1-nerved
or with additional sidenerves and sub-3-nerved, smooth on the keel,
about 8 mm. long; lemma oblong-cyhudric, about 21/2 mm. long or

but slightly longer, including the long-hairy, nearly 1 mm Ionquot; acute
callus, column straight or but slightly twisted, placed between the two
obtuse lobes of the lemma, central awn scaberulous only in lower
half, densely feathery in upper part, without a naked tip, very obtuse
in outline, the lateral awns naked. North Africa: doserts of the western
Sahara, Tunis and Algeria to Egypt, Sinai and Arabia. Also in South
Africa: from Damaraland and Namaqualand to Griqualand West
(Kimberley), south to Clanwilliam, Carnavon and Beaufort West

Culms 4-noded, sheathed all along, shortly pilose at the nodes, column of
awns up to S\'/o mm, long; central awn about 4 cm. long, lateral awns
about \'10 mm, long.

the nodes, subterete or angulous, striate and densely pubescent
exserted above the basal tufts; lower sheaths densely aggreo-ate, loose\'
white and papery, about \\ cm, long, keeled, densely\'\' striate and
hirtellous, especially on the nerves, with shortly pilose or ciliolate
broad hyaline rr.argins, upper sheaths much longer, up to 3 cm. lono-
very broad, inflated, the uppermost one by far the longest and up to
4 cm, long, all the sheaths gaping or more or less slipping from the
stems, the margins of the upper sheaths less ciliate, ligule a ciliolate
rim, auricles bearded, collar constricted; blades of all the leaves much
reduced, those of the lower sheaths more or less flat at the base
spirally curved and torted, scabrous-hirtel lous on both surfaces, 1 — 1 \'/a cm\'
long, about 1 mm. wide at the base or sliglitly broader, ending in a
subobtuse point, the other blades curved only and scarcely 1cm, Ion«-
blades of the culm-leaves still more reduced, convolute, strictly erect
and scarcely curved, much narrower than the sheaths; panicle scarcely
exserted, concealed by the base of the uppermost sheath, forced away
laterally, ovate-oblong, dense, up to 3 cm, long and about 1 cm,
broad, exclusive of the awns of the lemma, axis striate, subterete
scabrous-hirtellous, branches short, solitary, divided nearly from the
base, fascicled branchlets and pedicels short, scabrous, 3—4-flowered,
axils pubescent or hirtellous, pedicels scabrous, slightly thickened and
shorter than the glumes, here and there sometimes with a few lone
hairs; spikelets pallid or yellowish, glumes lanceolate, glabrous or
minutely scabrous, acute, shortly awned, the lower scabrous on the
keel, about 10 mm, long, 3-nerved, the lateral nerves half as long as
the midnerve and anastomosing with it, the upper glume 9 mm. Ion»-,
3-nerved, scabrous only on the keel above, the shorter lateral nerves

not anastomosing; lemma punctiilate-scabrous under a lens, including
the acute conical callus about 4 mm. long, linear-tubulous with a
somewhat oblique articulation and a minutely bilobed apex, tbe lobes
acutish with the column placed between tbem, the about 1 mm. long
densely hairy callus with much longer lateral hairs, reaching nearly to
the middle of the lemma, column very scabrous, slightly twisted,
more or less pubescent below the branching-point of the awns, central
awn scabrous in lower 1/3 part, plumose above, the tip slightly exserted
and naked, acutish in outline. South West Africa: Great Namaqualand
\'.............Aristida Hermaiini Mez

Glumes more acuminate than in tbe type and more unequal, the
lower IIV2—12 mm. long, the upper 9 mm. long; column elongate,
5—7 mm. long, distinctly twisted, central awn up to 31/2 cm. long,
naked in lower half part, the lateral ones up to 15 mm. long.

Blades, especially the culms and slieaths more or less dotted with tubercular
glands.

SuH\'rutescent perennial with a much branched woody rootstock, up
to 30 cm. high, not rarely much longer, culms many-noded, erect or
ascending, terete, striate, slender, minutely puberulous and covered
with many glands, lower internodes short, more or less aggregated,
upper ones gradually longer, exserted; sheaths tight, the lower ones
slightly shorter than the intei-nodes, terete, striate, gland-dotted, covered
with evanescent wool near the mouth and the margins, the nodes
with a Hake of wool, those of the thick cylindric innovations very
broad with rudimentary spiny blades, upper sheaths much longer,
conspicuously sliorter than the internodes, glandular or becoming more
or less glabrescent, ligule a short ciliate rim, auricles bearded with
a Hake of wool, collar a more or less pubescent villous line, becoming
glabrous; blades of the culm-leaves densely striate, convolute, sometimes
Hat below, subpungent, very rigid, spreading, glaucous, asperulous
beneath, hispidulous or pubescent on the upper surface, mostly scarcely
1 cm. long, sometimes longer and up to 5 cm. long; inllorescence
exserted, the peduncle terete, striate, puberulous and glandular, panicle
contracted, linear, somewhat spike-like but loose and interrupted at
the base, up to 10 cm. long, sometimes much reduced, rhachis striate,
angulous, glabrous, dotted here and there with glands, especially below,
bra\'nches short, solitary, divided from tlie base, few-llowered or

sometimes 1-flowered, smooth, the smooth pedicels much shorter than
the glumes and slightly thickened at the tips, uppermost pedicels longer
and sometimes half as longas theglumes;spikelets light-green or yellowish,
tinged with purple, glabrous, glumes lanceolate, acuminate, minutely trun-
cate, unequal, the lower 11 mm. long, 3-nerved, the lateral nerves more than
half as long as the midnerve and slightly anastomosing, smooth on the
keel, the upper glume 15 mm. long, 3-nerved or sub-5-nerved, nerves
not anastomosing, smooth on the keel; lemma linear-oblong, smooth
with an obtusely slightly bilobed tip, up to 6 mm. long inclusive of
the long-hairy, very acute, pungent, up to 2 mm. long callus, column
slender, twisted, about 5 mm. long; central awn glabrous or sometimes
very scantily plumose at the base, densely feathery above to the very
tip, the plumose part very obtuse in outline, the length of the central
awn nearly 3 cm., the lateral ones erect, naked and up to 15 mm.
long. South West Africa: Great and Little Namaqualand, south to

than the glumes, the latter less than 10 mm. long, the nerves not
anastomosing; central awn 2—3 cm. long, naked at the base, bearded
only above the middle, rarely scantily and adpressedly pilose in lower
part.........................30.

Panicle more oblong, lax; pedicels mostly longer than the glumes, the
latter more than 10 mm. long with anastomosing nerves; central awn
up to 5 cm. long, feathery all along or sometimes loosely long-pilose
at the base only and densely plumose above.

Densely caespitose perennial with few or wanting sterile innovations and
an oblique rootstock, culms up to 50 cm. high inclusive of the panicle, erect
or geniculate-ascending, simpleorsparingly branched below, elegant, many
in a tuft, terete, glabrous and smooth, slightly striate, naked upwards, the
leaves almost basal, few-noded, the nodes glabrous and dark coloured;
sheaths shorter than the internodes, the lower ones scale-like, chartaceous,
striate, glabrous, broadly ovate-lanceolate, upper sheaths tight, terete,
striate, smootli, more or less hairy or bearded at the summit, ligule a
densely ciliate rim, auricles bearded; blades involute, subulate-filiform,
glaucous, rigidulous but rather thin, more or less flexuous or curved, rarely

erect, striate, scabrous beneath, pilose or hirtellous on the upper surface,
those of the lower leaves mostly 10 cm. long or sometimes much
longer, those of the upper leaves much shorter and up to 5 cm. long;
panicle shortly exserted, the peduncle mostly concealed by the upper-
most sheath, up to 15 cm. long, elongate, strictly erect, rather many-
flowered, rhachis fdiform, subterete, scabrous, bi-anches capillary, flexuous
or erect,\' scabrous, solitary, much divided nearly from the base, few-
flowered or sometimes i-flowered, gradually becoming shorter above,
pedicels capillary, flexuous, scabrous, subclavate at the tips, commonly
longer than thequot;glumes; spikelets pale-greenish or yellowish, tinged
with purple, glumes linear-lanceolate, the lower 9-10 mm. long,
subulate-acuminate, ratlier abruptly narrowed into\' the .short awn,
3-nerved, the lateral nerves much shorter and anastomosing, glabrous
or slio-htly hairy or pubescent on the margins, serrulate-ciliolate at
the erose\'tip above, upper glume narrower, 12 mm. long, narrowed
above, tip obtusely emarginate or subbifid, not awned, 3-nerved with
anastomosing nerves, both glumes nearly smooth on the keels; lemma
papillose-scabrous in upper part, lanceolate-oblong, up to 5 mm. long,
inclusive of the 1 mm. long, acute callus, the latter with two collars of
hairs, the upper collar at the very base of the lemma with very long
hairs,\' reaching half the length of the lemma, wliich is pale or dark
coloured and obtusely emarginate at the summit, column about 8 mm.
long, strongly twisted, long-bearded in upper part, especially below
the knee, feathery part of central awn obtuse in outline without
exserted point, lateral awns naked, 10—12 mm. long. Beluchistan to

30. Central awn plumose in upper part with an exserted naked tip, the
feathery part acutish in outline.

Densely caespitose erect perennial with few innovations and not very
robust root-system, up to GO cm. high, inclusive of the panicles, culms
sparingly branched, erect, rather few-noded with smooth, constricted
sometimes geniculate nodes, terete, slightly striate, glabrous or minutely
puberulous or scaberulous; lower sheaths with reduced blades or
scale-like, yellow, glabrous, smooth and striate, the upper ones
narrower and tight, more or less slipping from the stems where the
culms are branched, much, shorter than the internodes, more or less
compressed, striate and scaberulous with hyaline margins, ligule
a densely ciliate rim, auricles long-bearded, the hairs more or less
spreading, the collar glabrous; blades narrow, linear, involute or not
rarely flat at tlie base, slightly scaberulous beneath, rough on the upper

surface with long white hairs especially near the base, not rigid,
ending in a setaceous not pungent tip; panicles erect, rather narrow
but loose, especially below, up to 10 cm. long or somewhat longer, in
depauperate specimens much shorter, mostly exserted or at^ first
sheathed by the uppermost leaf, axis angulous, scabrid, lower branches
semi-whorled or in less-developed panicles binate, capillary, naked at
the base over a short distance, branchlets and pedicels scaberulous,
the latter with subclavate tips; spikelets yellowish-white with a dark
spot at the base, glumes slightly unequal, glabrous, lanceolate-acuminate,
notched at tbe apex or slightly bitld with a mucro. the lower 8 mm.
long, the upper one 9 mm. long, both 3-nerved, the nerves of the
lower glume distinctly anastomosing, the keels smooth or slightly
scaberulous only at the tips; lemma punctulate or minutely papillose
in upper part, scarcely 3 mm. long inclusive of the 1 mm. long, acute
callus which is densely hairy, the hairs at tlie very base of the lemma
reaching half its length, the summit of the lemma scarcely lobed,
column of awns 5—7 mm. long, laxly twisted, with a very prominent
tuft of long hairs just below and above the knee, central awn up to
3 cm. long, feathery in upper part, naked or sometimes adpressed-
pilose below, lateral awns naked, up to 10 mm. long. North Africa:
Cape Verd Islands and Senegambia to Nubia and Aby,ssinia
..............Aristida papposa Trin. et Eupr.

Central awn plumose above the middle to the very tip, the feathery part
obtuse in outline.

Very dense and compact caespitose erect perennial w\'ith a very robust
rootstock, intravaginal innovations and a lew extravaginal ones• culms
erect, slender, 3—4-noded, elegant, strictly erect, simple, over 60 cm.
high, about 1 mm. thick, internodes nearly smooth, slightly striate
and terete, the terete nodes glabrous; lower sheaths yellow, reduced
to leafless scales, glabrous, upper sheaths tight, terete, substriate, nearly
smooth or scaberulous above, much shorter than the internodes, ligule
a short ciliate rim, auricles long-bearded, collar glabrous; blades
setaceously convolute, thin, mostly curved or flexuous, more or less
glaucous-green, glabrous and striate beneath, slightly scaberulous on
tbe upper surface with scattered long hairs and a tuft of long hairs
near the base at the mouth, ending in a setaceous not pungent point,
tbe basal-blades not over 4 cm. long,, the culm-blades 5—8 cm. long
or sometimes up to 10 cm. long; panicle long-exserted or at first
slieathed by the uppermost leaf, tlie peduncle terete and nearly
smooth, axis terete below, angulous and scaberulous above, straight,
branches capillary, mostly binate or divided nearly from the base.

sometimes fascicled, more or less peduncled, axils smooth, branchlets
and pedicels sligthly scaberulous, the latter not rarely more or less
tlexuous with scaberulous subclavate tips, mostly longer than the
glumes; spikelets yellowish not rarely tinged with purple, glabrous,,
olumes thin and papery, lanceolate-acuminate, the lower 8—9 mm.
bng, sub-3-nerved, the lateral nerves about 1/3 as long as the midnerve
and anastomosing, the keel smooth or slightly scaberulous below the
subobtuse apex, the upper glume narrower, 3-nerved, the lateral nerves
excurrent, not or scarcely anastomosing, close to the midnerve, with a
smooth keel, minutely bilobed or bifid at the apex with a mucro from
the sinus, mostly 9—iO mm. long; lemma cylindric, slightly bilobed
at the summit, 4 mm. long inclusive of the 1 mm. lotig callus, smooth,
densely punctulate-papillose all over under a strong lens, callus densely
hairy all over, the long hairs not reaching half the length of the
lemmas, column of awns 5 mm. long, twisted, pilose and feathery only at
the branching-point; central awn up to 2 cm. long, naked below or
sometimes nearly all along, lateral ones very fine, up to 9 mm long.
Western South Africa: South Angola to Great Namaqualand, east to Gri-
qualand West, Transvaal and Orange Free State, south to Pi\'ince Albert.

l\\iiricles more contracted with fasciculate branches, glumes more
equal, longer, about 14 mm. long, lemma 5 mm. long inclusive
of the callus, column slightly longer than in the type, 7—8 mm.
long, central awn up to cm. long, plumose nearly from the
base, lateral awns slightly longer than in the type, 12—13 mm.

Glumes of Ihe same length as in the type, but the column bearded
in upper part and on the knee, the central awn feathery from
the base to the tip, with a naked scabrous point. South Angola.
................var. Pearsouii Henr.

Central awn plumose all along, feathers very lax and long, divaricate;
column of awns u[) to l^Unbsp;long, not twisted.

Glaucous laxly caespitose rather robust perennial, the stout rootstock
with decumbent or ascending almost suffrutescent branches, culms up

to 50 cm. high inclusive of the panicle, erect or somewhatgeniculate-
ascending, 2—3-noded, elegant, about 1 mm. thick, terete, somewhat
sti-iate, slightly but distinctly puberulous or scaberulous, pruinose especi-
ally at the region of the nodes, the latter constricted and glabrous; lower

open above, about half as long as the internodes, striate, minutely
puberulous, with hyaline margins, ligule a densely ciliolate rim,
auricles very shortly bearded, collar glabrous; blades involute, filiform
but rigid and rather stilf, those of the innovations short, more or less
curved, 2—4 cm. long, the culm-blades up to iO cm. long or in very
robust specimens sometimes \'up to i5 cm. long, endino\' in a rioid
subpungent lip, striate, glabrous beneath, scaberulous-hirtellous on
the upper surface; panicle strictly erect, exserted, rather narrow, up

and pedicels, branches erect, solitary, bipartite above the base or more
or less fascicled in robust panicles, with smooth axils, the lono-er
brandies inclusive of the spikelets 6—7 cm. long, commonly much shorter
and few-llowered, pedicels variable in length but always shorter than
the glumes; spikelets erect, pale-yellowish, sometimes tinged with
purple, glabrous, lower glume 10—13 mm. long, lanceolate, acuminate
and more or less truncate, emarginate or minutely bifid at the apex
and minutely mucronate, 3-nerved, the lateral nerves half as long as
the midnerve and anastomosing with it, the upper glume narrower,
linear, 18—19 mm. long, involute above, subulate with an obtuse tip,
3-nerved, the lateral nerves close to the midnerve and excurrent,
more than half the length of the glume; lemma smooth below, slightly
scaberulous above, inclusive the long-pilose very acute callus, 4—5 mm.
long, callus about 2 mm. long; central awn with a minute naked tip,
4 cm. long, the lateral ones very fine, naked, up to 15 mm. long.

33. Densely caespitose up to 15 cm. high perennial; glumes 5-nerved with scabrous
nerves; central awn geniculate at the base, pubescent at the branching-
point of the three awns, feathery part very obtuse in outline.
Plants forming rather small, dense, about 2 cm. high tufts, with long-
exserted, 2-noded culms, the latter geniculately ascending, 5—15 cm.
long, terete, striate, quite glabrous and smooth; lower sheaths and
those of the innovations much reduced, the lowermost ones scale-like,
yellowish-white, deeply grooved or striate, glabrous, those of the
innovations with very rigid, curved and pungent up to 1 cm. long
blades, the margins ciliolate above, sheaths of the culm-leaves tight.

more or less keeled, striate and glabrous, much shorter than the
internodes, with more or less curved up to IV2 cm. long blades,
ligule a minute ciliolate rim, auricles shortly bearded or pilose, collar
glabrous; blades narrowly convolute, many-nerved, glaucous, glabrous
beneath, scaberulous or hirtellous on the upper surface; panicle e.xserted,
contracted, narrow, rather few-tlowered, up to 5 cm. long, peduncle
scaberulous or pubescent, axis sulcate and pubescent with ciliate axils,
branches scabrous-hirtellous, short, binate, the longer ones peduncled,
few-llowered, the shorter ones at the base are l-\'i-tlowered and nearly
sessile, strictly erect, pedicels pubescent with subclavate more or less
ciliate\' tips, much shorter than the glumes or the lateral ones sub-
sessile; spikelets glabrous, yellowish-green, tinged with purple, quite
yellow at maturity, glumes unequal, lanceolate-oblong with membra-
naceous margins, the lower up to 13 mm. long, shortly cuspidate, the
upper one up to 20 mm. long, gradually acuminate not awned, very
scabrous on tlie nerves only; lemma punctulate and rough under a
strontT lens, up to 5 mm. long inclusive of the very acute, densely pilose
up toquot;2 mm. long callus, column of awns twisted, up to 57^ mm. long;
central awnnbsp;cm. long, adpressed-short-pilose in lower i/3 part,

densely long-feathery in upper 2/3 part to the very tip, plumose part
obtuse in outline, lateral awns naked, very thin, up to 2 cm. long.

Laxly caespitose almost sulfrutescent, more or less creeping up to 40 cm.
quot;high perennial, from a much-brancbed nearly woody rootstock; glumes
3-nerved, glabrous; central awn straight, glabrous at the branching-
point, feathery part acute in outline.

Culms strictly erect or slightly ascending, rather thin and
elegant, compared with the very robust divaricately branched
root-system, terete, smooth, about 3-noded, innovations extravaginal,
probably also with few intravaginal ones; lower sheaths reduced to
pale, striate, smooth lealless scales, upper sheatbs tight, shorter than
the internodes, glabrous and terete below, striate upwards, quite smooth,
ligule a minute ciliate rim, auricles minutely pubescent only or some-
times glabrous, collar smooth; blades very narrow, linear, convolute,
setaceous, acute and subpungent, rather rigid, somewhat curved, 4-8 cm.
long, smooth beneath, hirtellous on the upper surface, glaucous, gradually
passing into the tip; panicle shortly exserted up to 20 cm. long, rather
depauperate, contracted but very lax and open, rhachis terete and
smooth below slightly scaberulous and more or less angulous above
with glabrous axils, lower branches solitary or 2—3-partite from the

base, upper ones single, all rather few-llowered and scaberulous, the
longer ones erectly ascending, naked below, 3—5-llowered, the shorter
ones 2-flowered or not rarely with only 1 flower, pedicels minutely
scaberulous, subclavate, about as long as the glumes or the lateral ones
much shorter; spikelets erect, pale-yellow and tinged with purple at the
base, glabrous, glumes lanceolate, the lower up to 12 mm. long, shortly
bidentate at the subobtuse apex, the lateral nerves very short scarce!v
\'1/3 the length of the glume, not anastomosing, upper glume acutish,
up to 15 mm. long, 3-nerved, the side-nerves much longer and close
to the midnerve; lemma smooth, 5\'/2 mm. long, inclusive of the 1\'/g tnm,
long, acute, hairy callus; column of awns 8 mm. long, sligthly twisted;
central awn up to 4 cm. long, naked in lower part, feathery to the
very tip but acute in outline, lateral awns naked, very thin, up to
15 mm. long. South West Africa: Great Namaqualand
...............Aristida garubensis Pilger

34.nbsp;Sheaths of the innovations densely white-woolly or at least the margins villous. 35.
Sheaths of the innovations and those of the culm-leaves glabrous or scabrous

very rarely the leafless scales at the base somewhat subtomentose or
slightly villous........................

one geniculate node placed just below the inllorescence with a leafless
sheath involving the base of the panicle.

Densely caespitose dwarf probably perennial species with elongate roots
forming 2 — 3^2 cm. high tufts, culms naked, long-exserted from the tufts,
up to 10 cm. long, the portion below the panicle 5 —6 cm. long, straight, very
thin, terete, subclavate at the summit, quite smooth or slightly scabrous
and pubescent only just below the node; basal outer sheaths reduced
to white or yellow, bi\'oad scales, which are sulcate-striate and glabrous
or scaberulous witb sparingly hairy margins, villous especially along*
the margins above, the inner sheaths with developed blades, more or
less tight, subcompressed, densely striate-sulcate, scaberulous or rough
with long spreading hairs above along the hyaline margins, ligule a
short ciliolate rim, auricles densely long-bearded, collar glabrous, the
sheaths are commonly only about 1 cm. long; blades up to 2 cm. long,
narrowly involute, obtuse, striate-sulcate, scaberulous beneath, hirtellous
on tbe upper surface and at the same time villous with long hairs on
both surfaces, becoming more or less glabrous afterwards, curved,
glaucous, tbe sheath below the inflorescence scabrous without villous
margins, up to 2 cm. long, the peduncle of tbe inllorescence veiy
minute, the panicle nearly sessile, geniculate or not rarely horizon-

Sheaths of the radical leaves densely white-woolly, culms strict, not geniculate
below the panicle, nodes glabrous.

Densely caespitose, minute, probably annual plants, forming small
hemispheric cushions, with densely aggregate leaves, culms glabrous,
lio-ule a sliort pilose rim; panicle few-tlowered, laxly subspicate, bearing
about 4 spikelets, the lateral llowers nearly sessile, glumes glabrous,
about equal, up to 9 mm. long, acutish and irregularly denticulate at
the apex, 3-nerved; lemma with a twisted about 2 mm. long column,
the densely hairy callus up to 2 mm. long, central awn \'I1/2 cm. long,
densely but shortly plumose in upper half, lateral awns naked, about

36. Glumes obtuse, at least the upper one; column of awns loosely twisted or
straight, but always well-developed and up to 4 mm. long, culm-nodes
glabrous.......................37.

Glumes very acute; column of awns not twisted, nearly wanting or very
short, up to -1 mm. long, culm-nodes retrorsely bearded.
Strictly erect. 40 - 50 cm. high perennial with a rather thick rhizome
and extravaginal innovations, densely obtected at the base by the
reduced (inn, mucronate scales, culms ascending, simple, terete, glabrous,
many-noded, leaves congested at the base of the culms, glaucous;
sheaths tight, terete, lower ones longer, upper ones shorter than tlie

internodes, ligule a short ciliate rim, auricles pubescent only, collar
glabrous; blades linear, acuminate, pungent, 3—4 cm. long, very rigid,
spreading, convolute and junciform, I\'/j mm. in diameter, glabrous
beneath, puberulous on the upper surface, prominently equally 5-7-
nerved; panicle effuse, pyramidal, 15—20 cm. long, very lax and open,
with a glabrous axis and filiform glabrous branches, the latter distinctly
bearded in the axils, lower branches subfascicled or semiwhorled,
mostly solitary and divided from the base, all the branches more or less
iterately branched, the longer branchlet in each branch 5—6-flowered,
the others 2—3-flowered, pedicels glabrous, filiform, slightly thickened
above, not rarely flexuous or curved, as long as or longer than the
glumes; spikelets linear-lanceolate, yellowish or greenish, glumes lan-
ceolate, acuminate, shortly awned, glabrous, 3-nerved, the lateral nerves
shorter and close to the midnerve, slightly anastomosing with it, the
lower glume up to 10 mm. long, smooth on the keel below, slightly
scaberulous or hirtellous on the keel above, the upper glume quite
smooth, up to 13 mm. long; lemma 3-nerved, linear-oblong, lead-
coloured, glabrous, punctulate-scaberulous under a strong lens, narrowed
above into a very short smooth beak, rounded at the base and suddenly
contracted into an oblique, laterally densely hairy, very acute, 2 mm.
long callus, the body of the lemma about 8 mm. long; awns somewhat
unequal, the central one erect, up to 20 mm. long, sliglitly pubescent
or glabrous below, soon becoming long-feathery to the very tip, the
plumose part very obtuse in outline, lateral awns naked, spreading,
16 mm. long, sometimes shortly adpressedly ciliate in upper part.

Densely caespitose erect or ascending perennial, branching from the
base, culms very slender, up to 15 cm. high, inclusive of the panicle,
erect or geniculate, 1-noded or sometimes 2-noded and the lowermost
node basal or nearly so, the other node at about half the length of
the culm, internodes terete or somewhat compressed, glabrous and
smooth; sheaths very tight, distinctly striate, slightly scaberulous, shorter
than the internodes the lowest broad, pallid, firm and persistent, much
reduced and scale-like, with very short blades, ligule a short ciliolate
rim, auricles pubescent, collar glabrous; blades setaceously convolute,
subacute, up to 5 cm. long, rigid, glabrous and smooth beneath, more
or less hirtellous or pubescent on the upper surface; panicle erect or
somewhat nodding at the summit, rather lax and loose, more or less

second 5-8 cm. long, with smooth rhachis and binate smootli branches,
the branchlets 1-2-flowered, the lowest branches up to 2 cm. long,
erect or ascending, fihform, nearly quite smooth; spikelets yellowish
or purple, glabrous, rather long-pedicelled or the lateral pedicels much
shorter than the glumes, glumes linear-lanceolate, subacumniate, sub-
equal 3-nerved, quite smooth on the keels, the lower 12Vo mm. long,
acuminate not awned, the upper one 13 mm. long, obtuse, emarginate
or distinctly bifid, mucronate from the sinus, the lateral lobes rounded ;
lemma oblong-cylindric, glabrous, purplish with a very acute, densely
hairy at least mm. long callus, the body of the lemma 3 mm. long,
column of awns 3-4 mm. long, slightly twisted; central awn 4 cm.
lono- feathery above the middle to the very tip, plumose part vei\'y
obtuse in outline, lateral awns naked, up to 17 mm. long. South West

long, column af awns as long as the lemma, feathery part of the central
awn very obtuse in outline.

Caespitose perennial with few innovations, culms elongate, erect or
geniculately ascending, about 3-noded, nodesglabrous, equally distributed,
terete, slightly striate, glabrous, 20 cm. long or longer, scarcely 1 mm.
thick \'with firm, pallid, subtomentose scales at the base; sheaths shorter
than \'the internodes, striate, slightly keeled, glabrous, ligule a minute
ciliolate rim, auricles densely long-bearded; blades complicate-convolute,
scarcely 1 mm. wide when expanded, 3—6 cm. long, somewhat curved
and spreading, scaberulous beneath, scabrous on the upper surface
and with long hairs especially near the base, the margins thickened;
panicle narrow, shortly exserted or sheathed by the uppermost leaf,
rather lax and subinterrupted with a scabrous axis, tlie branches binate
at least the lower ones, capillary, very scabrous, naked in lower half,
spikelets bearing only above, the pedicels very scabrous; spikelets
narrow, purplish or yellowish, the pedicels as long as the glumes or
those of the lateral flowers shorter, glumes unequal, the lower subacute
or subobtuse, quite smooth, 3-nerved, the lateral nerves much shorter
and anastomosing with the midnerve, 8 mm. long, upper glume 10 mm.
]onlt;i\' 3-nerved, tlie lateral nerves more than half as long as the midnerve,
quite smooth, obtuse at the summit, slightly bifid or emarginate, shortly
awned from the sinus; lemma tubulous, smooth with a densely hairy
acute callus, about 4 mm. long, the callus up to 1 mm. long, column
nearly straight, 3 - 4 mm. long, not twisted, from a more or less bilobed
apex of the lemma, articulation rather oblique; awns very unequal.

the central one scabrous belo w, feathery to the very tip, not exserted
tbe plumose part vei-y obtuse, 20~\'27 mm. long, the plumose part
14—20 mm. long, lateral awns scabrous, 8—10 mm. Ion«\'. South West
Africa: Angola................

Blades rigid and pungent, spikelets lar-ger, the glumes 11—13 mm. long,
column of awns sliorter than the lemma, feathery part of the centrS
awn acute in outline.

Perennial with a creeping rhizome, covered like the base of the culms
and the innovation-buds with scale-like pallid slieaths, the lowest scales
more or less hairy or villous, the upper glabrous, with much reduced
blades, culms erect, slender, fascicled, terete, glabrous and smooth
30-60 cm. long, many-noded; sheaths of the culm-leaves very tio-ht
striate, glabrous and smooth or minutely scaberulous under a strono-
lens, longer than the internodes or the upper ones slightly shorter,
ligule a ciliolate short rim, auricles minutely pubescent only, collar
glabrous; blades subulate, convolute and pungent, up to 5 cm. or
sometimes up to 10 cm. long, very rigid, mostly curved and spreading,
glabrous and smooth beneath, puberulous and hirtellous on the upper
surface; panicle ovate to pyramidal, very lax and open or sometimes
somewhat contracted, erect, up to 15 cm. long by 5—8 cm. broad,
with smooth rhachis, branches 2—3-nate or solitary and bipartite
nearly from the base, remotely and very scantily branched, finely
filiform, llexuous and smooth, the axils thickened and glabrous, lowest
branches up to 8 cm. long and 5—6-llowered, the upper branches

2—3-flowered,nbsp;pedicels smooth, curved or flexuous, rather long, those
of the lateral spikelets shorter than the glumes; spikelets very scattered,
often nodding, light green or yellowish, glumes lanceolate, gradually
narrowed, not awned, witb an obtuse, truncate or toothed apex, glabrous,

3-nerved,nbsp;the lateral nerves not or scarcely anastomosing, the lower
glume 11 mm. long, the upper one 13 mm. long; lemma subcylindric,
smooth, rounded at the base and suddenly narrowed into the oblique
laterally shortly hairy, very acute callus, which is nearly 3 mm. long,
the body of the lemma slightly narrowed above into a distinctly twisted
about 3 mm. long column, the total length of lemma, column and callus
about 10 mm.; central awn up to 2 cm. long, scantily hairy at tbe
base, soon becoming densely plumose to the very tip, the feathery part
acutish in outline, lateral awns 15 mm. long, very fine, glabrous or
sometimes scantily and adpressedly ciliate above. Soutli West Africa:

Sr-

\'V^r
~ I

Palisoï de Beauvofs gives us in the year 1812 the new genus Arthratherum
wliicli lie described on p. of liis Essai d\'nne nouvelle Agrostographie as follows :

Axis panifeulatus: Panicula snbcomposita, laxa.-Glumae membranaceae, saepius
niucronatae: superior Paleis longipr.-Valea infer, nuda vel barbata, aristata; Arista
3-partltâ, paleae infer, apici articulatâ, caducâ. — Squamae.... Stylus 2-partitus:
Stigmata villosa. — Semen oblongum, sulcatum.

Aristida hygromeirica and pungens ai\'e figured. Tlie first species is taken as the
^.ype of our section. Important for us is the statement that the lemma (palea inferior)
\'s awned, with an articulation at the apex of the valve, the awn tripartite, ^nsiirfa
pungens having no column and all the awns feathery, belongs to the section Stipa-
fjrostis. On p. 33 of his work Beauvois gives in a note the following observation;

»Le caractère le plus essentiel du Stipa, genre adopté par tous les Botanistes,
celui qui le distingue dé tous les autres genres, est d\'avoir une Arête articulée au
sommet de la Paillette inférieure. Le même motif doit servir à séparer VArthratherum
Aridida, sans quoi les caractères deviendraient négatifs, arbitraires, et ces-
seraient d\'être conséquens entre eux. Ce genre me parait donc très-naturel.quot;

As to the differences with the genus S^î\'pa, we have already indicated that a species
of Aristida belonging to tlds section, becomes a Stipa, if the lateral awns disappear
and tbat from a theoretical point of vieuw tlie two genera ought to be united.

Although Reiciienbacii accepted Arthratherum as a section of Aristida in the
year 1828, Nees still considered it to be a distinct genus in the year 1832. (Linnaea.
Vol. VII. p. 287). He described 3 species. His first species Arthratherum Hysirix (which
is tlie same as Aristida diffusa Trin.) is a true Arthratherum, the two other species
belong to the sections Stipagrostis and Schistachne. In his Agrostographia capensis
in the year 1841 Nees gives 10 species of this genus Arthratherum, only the first
one mentioned is an Arthratherum, the other ones belong to the two sections
already mentioned.

The monographers of the genus Aristida, Trinius and Ruprecht, accepted ^r^Ara-
thenm as a section of the genus in the year 1842 on p. 155 of their work, they
described 9 species, all belonging to tliis group as limited in our work, a section
\'laving an articulation at the summit of the valve, always a well-developed column
or at least a distinct beak and naked awns. Although other ways of articulation
were known to the Russian autliors, they based no sections on them. It is curious
that two North American species Aristida tuberculosa and Aristida desmantha were
not placed by them in the Arthratherum-gronp, although A. tuberculosa is easy to
I\'ecognize as a distinct member of this section.

Hirthei\'to there are about 40 species of this section known. Five of them occur
iti North America, in South America there are no representatives of this section.

All the other species of this section are Old World ones, Australia has about 7 species,
and India 4 species, the great bulk of the species is found in Africa, only a few
of them reach Palestine and Persia.

Culms more or less branched, slightly striate, nearly smooth, up to
80 cm. high; sheaths glabrous and striate, or more or less hairy and
villous especially along the margins, variable in length, slipping from
the stems or the upper ones tight, ligule short, ciliolate, auricles more
or less bearded, the collar glabrous; blades convolute, glabrous beneath,
scabrous above, 2—3 mm. wide or mostly scarcely 1 mm. when
inrolled, as much as 20 cm. long; panicle rather loose and open, up
to 20 cm. long and nearly half as broad, the axis slightly striate and
smooth below, scabrous and subangulous above, the branches distant,
ascending, mostly binate or subsolitary, very scabrous, rather stiff
naked over a long distance, branched only at the summit with very
scabrous branchlets bearing a few spikelets on short or sometimes up
to 10 mm. long pedicels, the latter very scabrous; spikelets strictly
erect and adpressed or the lower ones more or less spreading, yellowish-
brown, tinged with red, glumes linear-lanceolate to lanceolate, subequal,
the lower one with a longer awn and the position thus inverse, both
1-nerved, bifid at the apex with acute lateral lobes and a very prominent
awn from the sinus, the lower one scabrous on tbe keel, especially
above, up to 14 mm. long, tapering into an awn about half as long
as the body of the glume, the upper one narrower, smooth on the
keel, 13—14 mm. long with an awn about 6 mm. long, lemma
glabrous below, somewhat hispidulous or scabrous above, more or less
mottled, somewhat laterally compressed, up to 11 mm. long, inclusive
of the very acute, densely hairy, nearly 2V2 mm. long callus, awns very
scabrous, up to 3 cm. long, the bases curved in a semicircular slightly
contorted bend and the upper (lart of the awns straight and dellexed.

Column of awns longer, 8 mm. or more long, mostly 10—15 mm. long,
distinctly twisted and scabrous.

Calms strictly erect, much branched, smooth and slightly striate or
minutely scaberulous, subterete, 30 to 60 cm. or sometimes as much
as 1 meter high; sheaths more or less compressed, striate, glabrous
or sparingly hairy or the lowermost hairy throughout, mostly longer
than the\'\' internodes but slipping fi-om the stems, ligule a ciliolate
rin? auricles of the upper leaves pubescent or glabrous, those of
the\'lowermost leaves sometimes more or less latera/ly bearded, the
collar mostly glabrous; blades convolute, glabrous beneath, scabrous
and strongly nerved on the upper surface and along the margins,
2—4 mm.\'\' broad when expanded, up to 20 cm. long, more or
less Ilexuous; panicle loose, about 20 cm. long with rather distant
very scabrous, stiffly ascending branches and branchlets, bearing at
the summit a few spikelets on very rough pedicels, the latter about
5 mm. long or not rarely longer and as long as the glumes; spikelets
strictly ei^ect, yellowish-brown tinged with purple, glumes linear-
lanceolate oradually acuminate and moi\'e or less awned, subequal, the
lower including the awn slightly longer than the uppei- one, both
glabrous on the back, the lower scabrous on the keel, lanceolate,
T-nerved, not bifid at the apex but gradually narrowed into the awn,
glumes inclusive of the up to 10 mm, long awns, 25-30 mm. long;
femma glabrous except the slightly scabrous apex. 11—13 mm. long
inclusive of the densely pubescent up to 4 mm. long very acute callus;
awns scabrous, 3—4 cm. long, the bases forming a semicircular bend,
the terminal parts of the awns straight but more or less dellexed.
North America: From the atlantic coast, Massachusetts to Indiana and
Wisconsin, south to Georgia and Mississippi. Also found in Mexico.
................Aristida tuberculosa Nutt.

Column of awns always less than 2 cm. long, mostly not over 8-10 mm. long.
Caespitose erect elegant annual, 20-30 cm. high, inclusive of the
panicle, culms erect or geniculately ascending, branched from the
lower nodes, glabrous, slightly striate, distinctly scaberulous, subterete;
sheaths as long as or somewhat shorter than the internodes, rarely
much longer, tlie uppermost internode long-exserted, sheaths compressed,
glabrous or slightly scaberulous, striate, ligule shortly ciliate, auricles
more or less bearded with scattered long hairs; blades sometimes

quite flat, mostly involute, nearly smooth beneath, scaberulous or
liirtellous on the upper surface and with long hairs near the base and
along tbe margins, narrow, up to 20 cm. long, with a long setaceous
point, those of the innovations commonly shorter; panicle erect
somewhat secund, nearly half the length of the whole plant and about
•12 cm. long, linear-lanceolate, contracted but loose and open, branches
distant, unilateral, subgeminate, the longest erect or somewhat spreading,
naked in the lower part, many-flowered, the shorter branches at the
base are shortly peduncled or subsessile, few-llowered, branches and
branchlets very scabrous but without long white hairs in the axils and
on the pedicels (difference with te allied A. funiculata), the pedicels
rather short, those of the lateral spikelets very short and the llowers
nearly sessile; spikelets yellowish-brown or straw-coloured, erect and
adpressed, glumes slightly unequal, the lower up to 14 or 15 mm.
long, gradually narrowed and very shortly awned, merely acute,
glabrous, scabrous on the keel, sub-3-nerved, the upper one quite
smooth, 1-nerved, 10—11 mm. long inclusive tbe about 1 mm. long
awn; lemma smooth, scabrous only at the summit, more or less
punctulate all over, 10 mm. long, inclusive of the densely iiairy very
acute 1 mm. long callus, the column strongly twisted, about 5—10 mm.
long, rarely longer, articulation at the summit of the lemma very distinct;
awns scabrous, more or less spreading, the central one up to 30 mm.
long, the lateral ones about 25 mm. long. British India: Panjab. . .
.............Aristida Royleaiia Trin. et Rupr.

lower acute, not bifid, upper glume mostly 3/4 the length of the lower one. 0,
Glumes extraordinarily unequal, the lower 25—28 mm. long, inclusive of
the 3 mm. long awn, bifid at the apex, the awn from the sinus; upper glume
very short,scarcely 6 mm. long,acute, nearly totally hidden by tbelower one.
Slender, elegant up to 20 cm. high annual, branched from the base;
culms glabrous, smooth, geniculately ascending; sheaths slightly shorter
than the internodes, glabrous, striate or deeply grooved witb scaberulous
nerves, ligule a densely hairy rim, auricles long-bearded; blades llat
below, convolute upwards, acuminate, subpungent, base broader than
the sheaths, prominently striate, glabrous beneath, the upper surface
densely scaberulous or hirtellous, bearing scattered long hairs, especi-
ally along the margins and near the base, the blades about 5 cm. long
and about 1 mm. broad; panicle short and depauperate, narrow, shortly
• exserted or mostly involved by the uppermost sheath, bearing scattered
spikelets on short pedicels; axils of the panicle,- branches and pedicels
with long flexuous white hairs, the pedicels subtriquetrous; spikelets

pale-coloured, glabrous, glumes narrow, l-nerved; lemma smooth, some-
what punctulate, with a 2 mm. long, hairy, acute callus, about 5 mm.
lono-, not narrowed above, the column at the base as broad as the
lenfma, the lower part white, smooth and straight, not twisted and
broader than the upper part which is strongly twisted, the whole column
about 20 mm. long, very characteristically hairy nearly all over, the
hairs more or less spreading; awns scabrous, spreading or suberect,
the central one up to 7 cm. long, the lateral ones shorter, 6-6V2 cm.

Culms much branched from all the nodes; glumes long-awned, the awns
about 3-4\'/2 mm- long-

Somewhat rigid, glaucous, tufted annual; culms elegant, erect or geni-
culately ascending, glabrous, more or less striate and slightly scaberulous,
inclusive of the panicles 35-55 cm. high; sheaths glabrous, shorter
than the internodes, slipping from the stems and rolling in, the inter-
nodes naked nearly all over, deeply striate or grooved, more or less
compressed and keeled, slightly scaberulous, ligule a shortly ciliate
rim, auricles pubescent and more or less bearded with long tlexuous
hairs - blades glaucous, Hat at the base, narrowly setaceous and convolute
upwards, erect, longer than the sheaths, 10—15 cm. long, about 1 mm.
broad at the base, glabrous beneath, scaberulous on the upper surface
and bearing scattered long white hairs at the base and on the margins;
panicle up quot;to 20 cm. long, contracted, very narrow, somewhat dense,
few-branched or sometimes nearly simple, the branches somewhat
distant, binate or subsolitary, erect and adpressed, the branches and
branchlets scaberulous, capillary, bearing scattered long hairs; spikelets
])ale or brownish, more or less tinged with red, erect, glabrous, glumes
linear, narrow, keeled, the lower one 3-nerved, the midnerve scabrous,
the lateral nerves very short, running into the midnerve, lower glume
inclusive of the awn up to 30 mm. long, broader than the 1-nerved,
mostly up to 25 mm. long upper glume, which is smooth on the keel,
the quot;lumes are sometimes shorter and only 25 and 20 mm, long in
less-developed spikelets; lemma tubulous ore more or less compressed,
4—5 mm. long, glabrous, punctulate, scaberulous above, the very acute
hairy callus up to IV2 mm. long, the column as broad as the summit
of the lemma, very scabrous, strongly twisted, 21/2—3 cm. long, awns
scabrous, subequal or the central one longer, up to G cm. long or
sometimes much longer and about 9 cm. long, the tips of the awns

Culms simple or nearly so, sometimes branched from some of the lower
nodes; glumes acuminate-cuspidate or only very shortly awned.
Culms erect, densely tufted up to 30 cm. high, straight or somewhat
geniculate at the base, pale-green or somewhat glaucous, striate and
distinctly scaberulous; sheaths striate, glabrous, more or less compressed,
keeled, slightly scaberulous, much shorter than the internodes, ligule
a short ciliate rim, auricles bearded with long weak hairs, collar glabrous;
blades mostly flat or becoming involute afterwards, glabrous beneath,
very scabrous on the upper surface, prominently nerved, narrowly
linear, erect or divergent, with long white hairs especially near the
base and along the margins; panicles rather depauperate, contracted,
linear, few-flowered, up to 10 cm. long, mostly sheathed by the upper-
most leaf, branches rather distant, shortly peduncled, sparingly long-
hairy, subsimple or binate, erect and adpressed, mostly bearing a
subsessile spikelet at the base; spikelets green, tinged with brown or
sometimes purplish, erect, glabrous, glumes narrow, linear, the lower
sub-3-nerved, the midnerve scabrous, the lateral nerves very short
and anastomosing with the midnerve, the upper glume 1-nerved, narrower
than the lower one, the flrst glume about 20 mm. long or not rarely
longer and up to 30 mm. long, the upper glume 3—5 mm. shorter than
the lower; lemma glabrous and more or less punctulate below, mottled,
scabrous at the summit, without the callus about 4 mm. long, the
broadly conical, about 2 mm. long, shortly hairy callus with a sharp
naked point, a tuft of long white hairs at the very base of the lemma,
the hairs at the base nearly as long as the length of the callus; column
very scabrous as broad as the summit of the lemma, straight and not
twisted over a short distance, soon becoming strongly twisted with flat
windings, up to 4Va cm. long, awns subequal or slightly unequal, the lateral
ones about 41/2 cm. long, the central one mostly up to 5 cm. long.
North Africa: From Senegambia to Abyssinia, Eritrea and Arabia.
.............Aristida fiinieulata Trin. et llupr.

Lower glume about 22 mm. long as in the type but the upper
one much shorter and about 15 mm. long. Column mucli shorter
than in the type, only 3 cm, long. Cape Verd Islands. . . .
...............var. paradoxa Hour.

Glumes shorter than in the type, column much shorter, commonly
scarcely 2 cm. long, sometimes slightly longer; awns of
the lemmas much shorter than in typical A. funiculala and

9. Culms50-70cm. high, lower blades very long, up to 20 cm. long; mouth
oPthe sheaths and auricles not bearded; glumes narrowly linear, both

glabrous, somewhat punctulate; column of awns villous.
Thin eleaant ^labrous annual, culms erect, simple; sheaths tight,
o\'labrous quot;and smooth, ligule obsolete, a minute ciliolate rim ; blades
very narrow filiform, involute, glabrous and smooth beneath, scaberu-
lous on the upper surface with long hairs near the base and along

with verv short branches, bearing mostly but a few spikelets on very
short pedicels rhachis and branches scabrous; spikelets erect, mostly
pale or straw-coloured, glumes glabrous, 4-nerved, the lower scabrous
on the keel, the upper quite smooth; lemma terete. 5-6 mm. long,
the callus rather short, but long-hairy, the hairs exceeding the base
of the lemma, the naked lower part of the callus longer than its body,
deeply cleft with diverging acute lobes; column strongly twisted, up
to6V cm long, villous all over with long white hairs; awns suberect,
scabrous somewhat unequal, the central one about 41 cm. long, the lateral
ones 9—9V2 cm. long. West Africa: Senegambia to Nothern Nigeria. . .

Culms low inclusive of the panicle up to 15 cm. long, branched below;
blades\'short about 2 cm. long; mouth of the sheaths and auricles long-
bearded- lower glume broadly ovate-lanceolate, slightly bifid with a
short mucro from the sinus, upper glume twice as long, strongly bifid
with a long awn from the sinus; lemma with spreading, scattered
loner hairs; column of awns scabrous, without long hairs.
Culms filiform, densely tufted, thin and elegant, few-noded, internodes
terete or sligh\'tly compressed, glabrous and smooth, striate; sheaths
shorter than^ the internodes, glabrous and smooth, striate more or less
keeled, with hyaline margins, ligule short, densely bearded or ciliate,
the collar olabrous; blades narrow, filiform, involute, sometimes sub-
|)ungent, glabrous beneath, scaberulous on the upper surface, striate,
5-n^rved, the lateral nerves thickened, witb scattered hairs especially
near the\' base, blades scarcely V2 mm. wide or expanded about mm.
broad; panicles narrow and loose, strictly erect, axis terete, minutely
scaberulous, brandies binate, one long- the other shortly peduncled,
the longer one about 2 cm. long exclusive of the awns, 3—S-llowered,

the shorter one nearly sessile, 1—2-flowered, branchlets and pedicels
scaberulous, the pedicels as long as the glumes or mostly shorter, the
lateral ones nearly sessile; spikelets brownish or yellowish, glumes very
unequal, 1-nerved, the lower obtusely emarginate with rounded lobes
and a mucro between them, slightly scabrous on the keel, about 5 mm.
long, the upper about 10—11 mm. long, smooth on the keel, with
a delicate 2 mm. long awn from a rather deeply bifid apex,
the lateral lobes very acute; lemma up to 4 mm. lone nerved
and punctulate under a lens, the soft white scattered hairs erect
or somewhat spreading, narrowed into a scaberulous densely twisted
about 10 mm. long column, rarely the column up to 15 mm.
long, articulation prominent, somewhat oblique, the callus long-hairy,
the hairs exceeding the very base of the lemma, the naked part of
the callus deeply cleft, the lobes spreading; awns scabi\'ous somewhat
spreading, the central one up to 25 mm. long, the lateral ones about
15 mm. long. British India: Panjab and Scind to Beluchistan.
...............Aristida hystricula Kdgew.

Caespitose rather robust perennial, culms stout, up to l^g meter liioh.
terete, simple, smooth, sheathed nearly all along, sheaths longer than
the internodes, glabrous, striate, sometimes a flake of wool at the
mouth and with fugacious adpressed wool near the base, ligule a line
of short hairs, collar glabrous; blades linear, involute, rather firm,
tapering to a setaceous point, smooth beneatli, prominently nerved
and scabrous on the upper surface, up to 60 cm. long, 4—5 mm. broad
at the base, glaucous; panicle oblong to ovate, lax and open, nodding,
up to 30—40 cm. long, the axis smooth with distant, binate or solitary
branches, lowest up to 20 cm. long, obliquely spreading, reiterately
branched nearly from the base, with filiform scaberulous branchlets
and capillary pedicels, the latter more or less flexuous and as long as
the spikelets or longer; spikelets glabrous, yellowish or greenish, glumes
linear-lanceolate, acute, rather firm with hyaline erosely dentate tips
and narrow margins, 1-nerved, smooth, the upper 10 mm. long, the
lower about 1 mm. shorter or as long as the upper; lemma linear,
tubulous or convolute, about T\'/g mm. long inclusive of the 1 mm.
long callus, smootli, the callus densely bearded, strongly bifid, the
lobes subacute, the hairs of the callus much exceeding the very base
of the lemma, articulation very distinct, column strongly twisted,
nearly glabrous, rather short, about 5—6 mm. long; awns scaberulous,
erect or slightly spreading, somewhat unequal, the central one 20—25

11.nbsp;Foot of the au-ns shorter than 2 cm., mostly not longer than 15 mm., not

Foot of awns always more than 2 cni. long, mostly longer and 2\'/2-3
cm. long. North African species.

Loosely tufted robust perennial with rather few innovations, culms
simple or somewhat branched from the upper nodes, stout, thick, up
to 1 meter high, internodes glabrous, obsoletely striate and punctulate;
sheaths shorter\'than the internodes, glabrous, striate, with slightly
scaberulous nerves, culm-nodes swollen and protruding above the annular,
dark, glabrous sheath-nodes; ligule a shortly hairy rim, auricles of the
slieaths woolly; blades narrow, involute or more or less flat at the
base about 20 cm. long, 3—4 mm. wide when expanded, smooth beneath,
prominently nerved and scabrous on the upper surface; panicle more
than 30 cm. long, effuse, very lax and open, rather few-llowered for
such a laro-e inflorescence, branches binate or tripartite, sti\'iate, iterately

tips, mucir longer than the glumes, spreading, curved or Ilexuous, the
llowers nodding, glumes pale or tinged with red or purple, especially
at the base, not rarely with a black spot, 1-nerved, very unequal, gla-
brous, the lower one up to 7 mm. long, broadly ovate-lanceolate,
minutely bifid, the upper margins minutely serrulate-ciliate, much
broader than the narrowly hnear, 15—20 mm. long, upper glume, which
is bifid at the apex and shortly mucronate; lemma terete, including
the callus up to 9 mm. long, smooth, punctulate under a strong lens,
the callus slender, up to 2 mm. long, densely hairy with long hairs,
the naked prolongation manifestly bifid, column of awns scabrous,
prominently twisted, awns subequal, scabrous, up to 51/2 cm. long.
Northern tropical Africa: From the Senegal and the French Sahara

12.nbsp;Ligule a more or less woolly fringe, or a dense line of long soft hairs,

13. Lower internodes densely woolly, the uppermost ones glabrous; column of
awns rather short, about 6V2 mm. long.

from the base only or from some of the culm-nodes; lower sheaths
broad and papery, straw-coloured, adpressedly lanate on the back and
along the margins, soon becoming glabrous, shorter than the internodes,
nodes glabrous, lower internodes densely adpressedly woolly, the
uppermost villous only or becoming glabrous, ligule a very short ciliate
rim, passing into a dense flake of wool at the auricles; blades up to
2 mm. broad at the flat base, involute above, striate, glabrous beneath,
scabrous and shortly hairy or somewhat villous on the upper surface,
becoming glabrous afterwards, 10—45 cm. long with a subpungent tip;
panicle sub-pyramidal, subelï\'use or more or less contracted but lax
and open, rather thin, the axis with scattered white hairs and long-
bearded in the lower axils, branches fine, suberect or somewhat
spreading, very scabrous, up to 4 cm. long, pedicels as long as the
glumes or the lateral ones somewhat shorter, capillary, more or less
pilose, subclavate at the tips; glumes glabrous, l-nerved, the lower
broadly lanceolate, up to 51/2 mm. long, rounded at the tip and
somewhat denticulate along the upper margins and ciliolate at the apex
by a pencil of short hairs, the upper one narrower, slightly emarginate,
11—13 mm. long, lemma glabrous with a hairy, up to 1 mm. long
callus, column strongly twisted, awns unequal, the central up to 25 mm.
long, the lateral ones about 15 mm. long. South Africa: Kalahari

Lower and other internodes glabrous; column mostly rather long, up to
15 mm. long.

Compactly caespitose perennial with many innovations, culms erect,
simple or sparingly branched, up to IV2 meter high, 2—3-noded, lower
sheaths densely woolly, especially those of the innovations, afterwards
becoming glabrous, upper sheaths glabrous, smooth, somewhat loose,
nodes glabrous, tumid, ligule a short ciliolate line, auricles bearded or
long-hairy, with a flake of wool; blades narrowly linear, involute up
to 50 cm. long, sometimes flat below and up to 5 mm. broad, smooth
beneath, scabrous and shortly hairy on the upper surface; panicle
large, elfuse, very lax, up to 50 cm, long and G—10 cm. broad, many-
flowered, with smooth rhachis, branches 2~3-nate with filiform
branchlets and capillary flexuous pedicels as long as the glumes or
longer; glumes firm, glabrous, 1-nerved, the lower linear-oblong, obtuse
or emarginate, slightly ciliate ui)wards along the margins, half as long
as the upper one, which is linear-lanceolate, bifid at the apex and
10—13 mm. long; lemma terete, linear, 7—0 mm. long, smooth,
mottled with purple, slightly punctulate below, scabrous at the summit,

callus densely long-hairy, the naked base deeply cleft, 11/2—2 mm. long,
column slender, strongly twisted, scabrous or glabrescent, variable in
length, mostly abont 15 mm. long, or sometimes only half as long,
awns nearly equal, up to 25 mm. long. South Africa: Oranje Free
State and Griqualand West to Bechuanaland, Great Namaqualand,

Culms fascicled from much branched almost sulfrutescent many-noded
rhizomes or stolons; panicle rather short, fqw-llowered, contracted and
rather dense and narrow or thyrsiform, with erect and adpressed branches.
Quite glabrous, lower sheaths brownish, soon disappearing, the internodes
quite naked below, upper sheaths longer than the internodes, sometimes
slipping from the stems, nodes tumid; blades stillly erect, smooth
beneath, lirm, [)ungent, narrowly involute, terete, almost junciform,
not easy to expand, when llattened (after boiling with lactic acid)
scarcely up to 1 mm. wide with 2 marginal nerves and 3 much stouter
and broader scaberulous middle nerves; ligule a minute ciliolate rim,
auricles very shortly pubescent; panicle up to 10 cm. long and up to
3 cm. broad, exserted, lower branches binate, upper ones mostly
simple, erect and stilfly adpressed, axis of the panicle, axils and branches
glabrous, branchlets and pedicels slightly scaberulous, the latter as long
as the glumes or the lateral pedicels somewhat shorter, with subclavate

tips; glumes 1-nerved, the lower broadly lanceolate, 5 mm. long,
mimitely ciliate at the tip, the upper one linear-lanceolate, 8 mm.
long with an obtuse or erose tip; lemma smooth, punctulate under a strong
lens, inclusive of the long-hairy callus about 8 mm. long, the scarcely
1 mm. long callus obtusely bifid at the naked tip, column twisted,
about 5 mm. long, awns scabrous, the central otie 23—25 mm. long,
the lateral ones up to 18 mm. long South Africa: l.ittle and Great

15. Culms many-noded; panicles somewhat contracted not elhise and lax,
rather narrow but not dense as in A. dasydesmis, much longer than
broad, 15-20 cm. long, up to 3 cm. wide, the lower branches erect
or .somewhat spreading, up to 4 cm. long, the spikelets erect or
somewhat divergent, glumes rather thin, the lower very broad, scarcely
5 mm long, the upper one narrow, lanceolate, 9—10 mm. long, lemma
about GV2 mm. long, the column scarcely 41/2 mm. long; awns nearly

equally spreading or the central one more divergent, the latter about
20 mm. long, the lateral ones about 15 mm. long.
Densely caespitose plants; sheaths shorter than the internodes, smooth,
scarcely striate; nodes and mouth of the sheaths glabrous, ligule a
shortly ciliate rim, auricles pubescent; blades narrow, convolute, with
a long subpungent tip, about 10 cm. long, strongly nerved, glabrous
and smooth beneath, scabi \'ous to hirtellous on the upper surface; branches
and branchlets of the panicle scabrous, the scabrous pedicels as long
as or longer than the glumes, or the lateral pedicels shorter, tips of
the pedicels subclavate and densely scaberulous, the lower glume
somewhat scaberulous all over, rather broad and abruptly narrowed
into the subobtuse minutely ciliolate tip, the upper glume gradually
narrowed into a scarcely emarginate subacute tip; callus deeply bilid,
long-hairy, up to 1 mm. long, the lemma slightly scaberulous, often
mottled,the column scaberulous and strongly twisted. South West Africa:

Culms 1—2-noded; panicles effuse, nearly as long as broad, up to 15 cm.
long, lower branches spreading, up to 7 cm. long, spikelets nodding
or suberect, glumes rather firm, the lower linear-oblong, 6 — 7 mm.
long, the upper narrower, lanceolate to linear, 13—15 mm. long; lemma
11—12 mm. long, the column up to 6 mm. long, awns nearly equally
spreading, the central one up to 35 mm. long, the lateral ones 30 mm. long.
Somewhat glaucous densely caespitose perennial, 30—60 cm. high,
culms terete, firm, glabrous and smooth; sheaths tight, smooth, scarcely
striate, glabrous or the lower ones covered with a fugacious wool,
shorter than the internodes, ligule a line of very short hairs, auricles
pubescent only; blades convolute, those of the internodes short, the
culm-blades up to 30 cm. long, scarcely 2\'/2 mm. broad when expanded,
rigid, curved or llexuous, smooth beneath, scabious or hispidulous on
the upper surface; rhachis of the panicle strict or slightly llexuous,
thebranches2—3-nate, sparingly and remotely branched, the branchlets
filiform or capillary, scabrous, llexuous, pedicels very fine, often curved,
the longer ones as long as the glumes; spikelets yellowish-brown,
sometimes purplish, glumes rounded on the back, glabrous, 1-nerved,
the lower obtuse, the upper one witb an obtuse bidentate tip; lemma
almost smooth or scaberulous at the summit, the callus shortly bifid,
densely hairy, column scabrous, strongly twisted, variable in length,
awns scaberulous. South Africa: From the Coast Region to Transvaal,

Panicle effuse, large and open, 20 cm. long or longer, the
branches spreading or divaricate, about 7—8 cm. long,
naked below, lower glume about 8—9 mm., upper one
\'16—18 mm. long, lemma 12—14 mm., column 7—8 mm,
long.............var, geuuhia Henr.

Panicle subcontracted, more dense, the branches erectly
ascending or somewhat adpressed, much shorter than in
the type, upper glume 12—15 mm, long, column 7—8 mm,
long..............var. densa Henr.

Sheaths lanate or woolly pubescent, especially the lower ones, the .
uppermost ones always glabrous.

Panicle contracted, somewhat narrow, 10—12 cm. long,
the branches erectly ascending, lower glume 6—mm.,
upper one 15 mm. long, the lemma 10 mm. long, blades
short or rather short, mostly not reaching ttie panicle.
............var. Eckloniana Henr.

Panicle contracted as in var. Eckloniana, up[)er glume
17—18 mm. long, the lower one about 10 mm. long,
lemma 12—13 mm, long; blades longer mostly reaching
the panicle.......var. Schradoriana Henr.

Colunm very short, scarcely developed, only a not twisted
about Va mm, long beak, upper glume 11—12 mm, long,
the lower much shorter, about 4 mm. long; lemma
about 10 mm. long, blades short, about 5 cm. long.
...........var. pseudoUystrix Hour.

Column well-developed, \'21/0—\'i\' mm. long, twisted, glumes
6—7 and 12—15 mm. long, lemma 1! —12 mm, long,
panicle about 10 cm. long, blades longer than 5 cm, .
...........var. breveslipitaia Henr.

Bushy-branched very elegant plant, culms very slender, 10—2U cm.
high, ascending, the lowermost internode by far the longest, more than
half the length of the culm without the panicle, terete, densely pubescent,
the nodes glabrous; sheaths glabrous, pubescent only at the. throat and
on the auricles and collar, shorter than the internodes, the uppermost
ones rather broad with hyaline margins and more or less reduced

blades, the latter Hat or somewhat involute, spreading, glabrous beneath,
puberulous on the upper surface, strongly nerved, 1-3 cm. long, mostly
ending in a tine acute point; panicles rather long-peduncled, very
numerous, fasciculately arising from the uppermost node, sheathed
together at the base by the uppermost sheath, each panicle very nai-row,
mostly 1-3-ilowered, the axis angulous and scaberulous, the branches
very short, about l-llowered, the pedicels short, the spikelets erect and
subsessile; glumes unequal, 1-nerved, the lower glabrous and smootli,
slightly scaberulous only on the keel above, acute, the tip bilid with
a mucro from the sinus, about 10 mm. long, the upper glume twice
as long as the lower one, narrowed into a scarcely awned acute tip;
lemma about 8 mm. long, glabrous below, scaberulous at the summit,\'
tlie densely pubescent very acute callus about \'2 mm. long, column\'
strongly twisted, scabrous, up to 20 mm. long, awns subequal, divergent
but not contorted at the base, about 4—5 cm. long, very fine. Lmver
California...........

Densely caespitose erect perennial, much branched from the base and
more or less so from the nodes; culms slender, 3-4-noded, 10—30 cm.
high, subcompressed, striate, densely pubescent or the upper ones
hirtellous, nodes glabrous; sheaths glabrous or more or less puberulous,
compressed and striate, pubescent at the throat and on the collar^
the ligule a ciliate rim; blades strongly nerved, mostly less than
5 cm. long, involute, ending in a fine acute point, scabrous on both
surfaces and pubescent on the upper surface; panicles few-llowered,
strictly erect, very narrow, inclusive of the awns up to 10 cm. loii\'i-\'
the axis puberulous, angulous or triquetrous, branches solitary or tlie
lower ones binate, bearing only a single fiower, one llower nearly
sessile, the other one with a pedicel as long as or somewhat shorter

erect, purplish, glumes unequal, 1-nerved, the lower scaberulous on
the keel, up to 9 mm. long, with a bifid tip and a mucro from the

sinus, the upper one up to i6 mm. long, inclusive of the nearly i 1/2 mm.
long awn from a bifid apex, the lateral lobes acute; lemma fusiform,
glabrous or slightly punctulate below, distinctly scabrous above, together
with the 1 mm. long, acute, callus, up to 6 mm. long, the callus shortly
hairy below, with longer hairs at the summit, the hairs much sur-
passing the true base of the lemma, column scabrous, densely twisted,
up to \'15 mm. long, awns scabrous, spreading, more or less contorted
at the base, otherwise quite straight, nearly equal, about 372—4 cm.
long. North America: California and northwestern Mexico. ....
...............Aristida californica Thiirber

Culms many-noded, sti\'ictly erect; sheaths glabrous, shorter than the
internodes, smooth, terete and tight, ligule a shortly hairy rim; blades
filiform, involute, the lower up to 30 cm. long, the upper 10—\'15 cm.
long, very narrow, erect or somewhat spreading, very acute but not
pungent; panicle shortly exserted, narrow, very dense and almost
spike-like, 15—20 cm. long, axis densely lanate, the branches numerous
and very short, adpressed, the spikelets nearly sessile, narrow, glabrous,
the glumes unequal, botli shortly awned, the lower one 11 —14 mm.
long, the upper one 20—24 mm. long; lemma with a very acute,
elongate, shortly pilose, up to 2 mm. long callus, the column 2—272 cm.
long, strongly twisted, scabrous, the awns about equal, scabi\'ous,
spreading, about 5 cm. long. South West Africa: Kalahari desert . .
................Aristida mollissima Pilger

19.nbsp;Panicles very dense and spike-like, the pedicels very short, the spikelets

20.nbsp;Awns very unequal, the lateral ones nearly half as long as the central one;

Awns nearly equal or the lateral ones but slightly shorter than the central
one; column of awns less-developed, about 0 mm. long.
Densely caespitose perennial with intravaginal innovations, culms
about 30 cm. high inclusive of the panicles, erect or slightly geniculate
at the nodes, terete, glabrous, simple, scabrous below the panicle, the
uppermost internode rather short; sheaths tight or somewhat gaping,
longer than the internodes, subterete, striate, more or less scabrous,
ligule a minute ciliate rim, auricles pubescent; blades narrowly linear,
complicate, scarcely 1 mm. broad when exjianded, glabrous beneath.

hirtellous on the upper surface, with scabrous thickened margins,
when dried almost cylindriform, 20 cm. long or longer, those of the
innovations still longer, overtopping the panicle; inllorescence sheathed
at the base by the uppermost leaf, pale, shining, very densely spiciform,
mclusive of the long awns about i5 cm. long, without the awns
5—7 cm. long, cuneate at the base, ovate in outline and about 3 cm.
broad, axis glabrous and smooth, branches very short, spikelets bearing
from the base, the flowers densely congested, the pedicels scabrousquot;
short, about 2—3 mm. long; spikelets yellow, glumes very unequal,
1-nerved, the lower minutely scabrous, gradually passing into the
3 mm. long awn, up to 12 mm. long, the keel scabrous above, u[)per
glume glabrous with a smooth keel, much nari\'owed above, tb.e margins
more or less inrolled, without the awn about 25 mm. long, bifid\'\' at
the apex, the lateral lobes about 1 mm. long, long-awned from tbe
sinus wjth a 9—10 mm. long awn; lemma fusiform, brownish, smooth
or slightly scaberulous at tbe summit, inclusive of tbe very acute
densely bearded about li/^ mm. long callus, up to 6V2 mm. long, the
column erect, glabrous, slightly twisted, about G mm. long, more or
less dilatated below the branching-point of the awns which are about
8 cm. long or the central one up to 9 cm. Northern East Africa:
Somaliland....................

Caespitose perennial, culms erect, elegant, simple or somewhat branched
from the middle nodes, sheathed all along, glabrous, scaberulous only
below the panicle, up to 30 cm. high; sheaths glabrous, striate, shorter
than the internodes, ligule a short ciliolate rim, auricles ciliate only
not bearded; blades rather short, narrow, linear, convolute-setaceous,
acute, filiform, glabrous, scabrous only along the margins; panicle
exserted, spike-like, very dense, ovate-oblong, without the awns up to
4 cm. long, scarcely 1 cm. broad, axis glabrous, the branches very
short, adpressed, 3—5-nate, spikelets bearing from the base, the
flowers densely fascicled and crowded, very shortly pedicelled, glumes
bnear-lanceolate, yellowish, very unequal, 1-nerved, scabrous, the lower
G mm. long, the upper 10 mm. long, both bidentate at the tip with
a mucro or a short awn from the sinus; lemma lanceolate, nearly
smooth, inclusive of the 1 mm. long, very acute, somewhat
oblique, long-hairy callus, up to 4 mm. long, the hairs of the callus
much surpassing the very base of the lemma, column scaberulous
loosely twisted or scarcely so, awns erect, scabrous, the central one

about 40 mm. long, about twice as long as the lateral ones. North
East Africa: Somaliiand..............

Lower, glume not bifid, acute or shortly awned; column 15—20 mm. lone.
Culms erect or somewhat arcuate, tei-ete, striate, glabrous, glaucous,quot;
elegant, with glabrous nodes; sheaths tight at least the upper ones,\'
striate, smooth, about 5 cm. long, ligule a rather long-pilose rim, auricles
long-bearded, collar glabrous; blades of the upper leaves flat at the
very base, convolute, glaucous, setaceously acuminate, glabrous beneath
puberulous or hirtellous on the upper surface, the margins not thickened\'
9—11 cm. long, expanded scarcely 1 mm. broad; panicle shortly exserted\'
narrow, densely contracted, spiciform, without the awns about 10 cm.\'
long, about 1 cm. broad, strictly erect, rather stilf, axis subterete or
subangulous, somewhat scaberulous, not visible, the dense panicle not
interrupted, branches solitary, strictly erect, much divided to the
base, the branchlets erect and adpressed, scaberulous, the pedicels
subcompressed, subsessile and slightly scabrous; spikelets yellowish-
green or glaucous, erect and adpressed, glumes unequal, glabrous,
1-nerved, the lower 6—8 mm. long, scabrous on the keel, acute or
acuminate, shortly awned, the upper one smootli on the keel, narrower,
than the lower one, 15-16 mm. long, distinctly bifid at the apex with\'
a scarcely 5 mm. long awn from the sinus; lemma glabrous, slightly
punctulate-scabrous at the summit, rounded at the base, inclusive of
the callus about 5 mm. long, the callus curved, very acute, about
1 mm. long and densely bearded laterally, the lemma not na\'rrowed
above, the scabrous, twisted column about 20 mm. long, awns scabrous,
yellowish or purplish, the lateral ones erect, 25—35 mm. long, the
central one slightly divergent and curved at the base, about 6 cnrion^.
North East Africa: Somaliiand.......... _

-2. Column of awns less than 5 cm. long, mostly not longer than 4 cm., glumes
not of a very firm texture, commonly thin or papery, very \'unequal
or subequal, the upper however never longer than 3 cm.

Column of awns very long, always more than 5 cm. long, mostly TV ~8
cm. long, glumes of a very firm coriaceous structure, the lower 2\'cm.
long, the upper one about 4 cm. long.

Culms slender, rigid, glabrous, branching at the base, up to 60 cm.
high; sheaths closely adpressed, minutely ciliate at the mouth, dee])ly
grooved and compressed, not rarely more or less hairy, tlie hairs
arising from tubercles, especially hairy along the sheath-margins, ligule

a short ciliate rim, auricles rather long-pilose, collar glabrous; blades
rather short, rigid, subulate, up to 10 cm. long or longer, convolute,
expanded scarcely 1 mm. broad, nearly smooth beneath, scaberulous
on the upper surface; panicle very narrow, nearly simple, up to 25
cm. long without the awns, the branches strictly erect, adpressed,
binate, bearing mostly but a single spikelet, one spikelet shortly, the
other long-pedicelled, pedicels stout and rigid, stiffly erect, scabrous
on the margins, otherwise smooth, with a subclavate tip which has a
lateral tuft of short hairs; spikelets brownish to reddish, glumes glabrous,
the lower with an obtuse bifid tip and a short awn from the sinus,
prominently 5-nerved or sometimes sub-3-nerved by the fusion of the
lateral nerves, upper glume acute, 1-nerved, somewhat convolute,
with a nearly 6 mm. long awn; lemma narrow, convolute, glabrous,
punctulate under a lens, without the callus 8 mm. long, the densely
hairy callus up to 41/2 mni. long, the point naked and very acute,
column very strongly twisted, nearly glabrous, awns somewhat unequal,
the central one about 13 cm. long, the lateral ones about 12 cm. long,
lodicules striate, as long as the 3 mm. long palea. North Australia and

23.nbsp;Central awn curved in a semicircle, strongly retlexed, much stouter than

the lateral ones. Panicles very elegant, flexuous and nodding at the
summit, the branches and spikelets drooping.........24.

Central awn not curved or rellexed, straight. Panicles stiffly erect or slightly
curved, the branches and spikelets erect and adpressed, not drooping, . . 25.

12—14 mm. long, the upper one 24—2G mm. long; lemma about 9 mm.
long inclusive of the callus; column of awns 21—24 mm. long.
Densely caespitose, branched below and from most of the nodes, rather
rigid, glabrous and glaucous. Culms slender, 3—4-noded, up to 80 cm.
high or longer, the panicles nearly half the length of the whole plant,
internodes terete, slightly scaberulous only, laterally grooved; sheaths
much shorter than the internodes, slipping from the stems, more or
less compressed and striate, with hyaline margins, ligule a very short,
ciliolate rim, auricles long-bearded, the collar a villous or bearded line;
blades somewhat rigid, glaucous, erect or Spreading, rather long to
very long, at least up to 20 cm. long, those of the innovations commonly
much shorter, the culm-blades fiat at the base over a long distance
or becoming convolute upwards, ending in a setaceous point, glabrous
beneath, scaberulous or hirtellous on the upper surface, about 2 mm.

bi-oad ; panicle very lax, about ^ dm. long with very distant, rather
short, llexuous or curved, capillary branches which bearquot; at the summit

2—5nbsp;tlowers on very long pedicels, the axis of the panicle striate and
angulous, more or less scaberulous, the branches binate or the upper
ones solitary, without the spikelets about 5 cm. long, very scabrous
the scabrous pedicels subcompressed and subclavate at the summit-
spikelets glabrous, nodding, glumes very unequal, the lower prominently

3-nerved,nbsp;very acute but scarcely awned, the upper one 1-nerved.
finely acuminate but not distinctly awned; lemma with a densely
hirsute about 2 mm. long, very acute callus, narrow, convolute, nearly
glabrous and smooth, column of awns strongly twisted, gradually
narrowed above to the central awn, which is scabrous and rigid and up
to 10 cm. long or slightly shorter, the lateral awns thinner, somewhat
spreading and curved, about 9 cm. long. Australia: Queensland.
..............Aristida superpendens Domin

Sheaths scabrous or hirtellous, the whole plant rough, spikelets pale, much
smaller, the lower glume about 11 mm. long, the upper one about
17 mm. long; lemmanbsp;mm. long inclusive of the callus; column

Culms numerous, densely tufted, somewhat glaucous, rigid and slender,
up to 70 cm. long or longer, glabrous, sheathed all along, the panicles
shorter than half the length of the whole plant, internodes terete
slightly striate, distinctly scabrous; sheaths tight, not slipping from the
stems, which are simple or scarcely branched at the base, the sheaths
terete and striate, very scabrous, about as long as the internodes or
somewhat shorter, ligule a short ciliate rim, auricles pubescent and

shortly ciliate, the collar without a villous line, scaberulous only; blades
up to 3 dm. long, somewhat ciliate at the mouth, rigid, glaucous, very
narrowly convolute, subjunciform, more or les spreading, curved or
flexuous, ending in-a subpungent setaceous tip, very scabrous on both
surfaces, those of the innovations sometimes with bearded auricles-
panicle very narrow, lax, much interrupted, 25—30 cm. lono-, slender
and elegant with very scabrous axis, branches binate or the upper
ones solitary, very scabrous, naked at the base, at first erect or
adpressed, afterwards curved and flexuous, drooping, the shorter branch
1—2-llowered, the longer branch 2—3-llowered, the pedicels very
scabrous, subclavate at the apex, those of the lateral spikelets rather
short, the other ones much longer and about as long as or longer than
the glumes; spikelets pale-yellowish, tinged with brown, ad tnaturity
nodding, glumes acuminate, but not or scarcely awned, the lower one
3-nerved, the upper one 1-nerved, both glabrous; lemma narrow,

convolute, smooth, with a shortly and adpressedly hairy, scarcely
IV2 mm. long very acute callus, the column strongly twisted, very
scabrous, gradually passing into the curved, rigid central awn, which
is about 7 cm. long or shorter, the less rigid, erect, llexuous lateral awns
mostly somewhat shorter than the central one. Australia; Queensland.
.................Aristida liirta Domiii

25.nbsp;A wns not curved at the very base, quite straight, stiflly erect or somewhat

spreading. Culm-blades more than 3 cm. long, mostly long to very
long, rarely short, but in that case the lower glume is always longer
than 10 mm. Old World species...............26.

Awns curved at the very base, otherwise straight, equally nearly horizon-
tally spreading. Culm-blades very short, mostly 1-3 cm. long, very
rartly somewhat longer. New World species.

Densely caespitose with intravaginal innovations, much branched from the
base and nearly all the nodes; culms erect or ascending, rather thin and
elegant, glabrous, 20—40 cm. high, terete, shghtly striate; sheaths much
shorter than the internodes, subcompressed, glabrous, with hyaline margins,
ligule a ciliolate rim, auricles shortly pubescent, collar glabrous; blades
involute, more or less spreading, scaberulous beneath, pubescent on
the upper surface, deeply striate or grooved, ending in a line point,
very narrow, scarcely 1 mm. broad when expanded, mostly not over
3 cm. long, or rarely some of the lower blades in very robust specimens
longer and up to 10 cm. long; panicles narrow, 3—6 cm. long or
rarely longer, few- to several-llowered, the spikelets single or in pairs,
one longer, the other shortly pedicelled, adpressed, the pedicels slightly
scaberulous, up to 5 mm. long or the lateral ones only 1—2 mm. long;
spikelets pale or greenish, sometimes tinged with purple, glumes
glabrous, unequal, 1-nerved, the lower acute, 5-6 mm. long, slightly
scabrous on the keel above, the upper one narrowed into a slender
point, scarcely awned, 10—12 mm. long, smooth on the keel; lemma
mottled at maturity, glabrous below, scaberulous at the summit,
5—7 mm. long, the densely pubescent very acute callus about I1/2 mm.
long, column very slender, twisted, scabrous, somewhat variable in length,
mostly 10—i5 mm. long or sometimes only 6 mm. long; awns about
equal, fine, scaberulous, 2—3 cm. long. North America: Arizona to

rather long awn, but in that case this awn always from a deeply bifid
apex with long lateral setulae................27.

Glumes extraordinarily long-awned, the awns 8—10 mm. long, those of
the upper glumes up to 15 mm. long and not from a bifid apex.
Laxly caepitose perennial with intra- and extravaginal innovations,
culms strictly erect, simple, about 50 cm. long, inclusive of the panicles,
glabrous and smooth, few-noded, the nodes glabrous; sheaths mostly
shorter than the internodes, glabrous, striate, with hyaline margins
ligule a densely ciliolate rim, auricles long-bearded; blades linear
\'IV2 —2 mm. broad, gradually long-acuminate, up to 30 cm. long, erect,
scaberulous beneath, scabrous on the upper surface and alon«- the
margins, those of the innovations narrower, convolute, setaceous
V2 mm. thick, expanded about 1 mm. broad; panicle elongate, narrow-
but not dense, more or less interrupted, the scabrous branches binate
or solitary upwards, elongate and adpressed, naked below, about
6-7 cm. long, gradually becoming shorter, rather few-flowered the
spikelets adpressed, the terminal ones with a 10 mm. long pedicel
the lateral ones shortly pedicelled, all clavate at the summit; spikelets
narrow, glabrous, glumes lanceolate, gradually long-acuminate-awned,
1-nerved, tho lower one I\'i—13 mm. long, with a 8—9 mm. long,\'
fine awn, scabrous on the keel, the upper one smooth on the keel
18—19 mm. long with a 13—14 mm. long awn; column erect, at least
10 mm. long, not known in a mature state; awns erect, somewhat
unequal, the central one about 6\'/2 cm. long, the lateral ones 5 cm.

29.nbsp;Column of aw-ns always less than 3\'/2 cm. long, mostly 10—30 mm. Ionquot;

Densely caespitose, strictly erect up to 1 meter high, robust, somewhat
glaucous perennial, culms simple below, stiffly branched from some

of the middle and upper nodes, glabrous, nearly smooth, internodes
compressed, lowermost one rather short, about 5 cm. long, naked, the
sheaths delapsed, the following internode very long, up to 20 cm. long,
the sheaths shorter than the internodes, broad, shpping somewhat from
the stems, ligule obsolete, very minutelyquot; ciliolate, the auricles shortly
pubescent; blades flat or becoming involute, 10—16 cm. long, acute,
2—3 mm. wide, glabrous beneath, minutely scabrous on the upper
surface, glaucous with scabrous margins; panicle 20—25 cm. long,
narrow, linear, contracted and rather dense, the branches binate, divided
from the base, the branchlets rather short, bearing but a few spikelets,
the spikelets more or less condensed, pale or greenish; glumes glabrous,
very unequal, 1-nerved, with slightly scabrous keels, the lower scabrous,
acuminate, shortly awned, about 10—I2V2 mm long, the upper one
narrower, inclusive of the scarcely 5 mm. long awn from the bifid apex,
about 20—22 mm. long; lemma 9—10 mm. long inclusive of the densely
hairy, very acute, about 3 mm. long callus, linear or tubulous, gradually
narrowed into the column, finely punctulate under a strong lens, column
scabrous, strongly twisted, awns very fine, subequal, scabrous, up to
6 cm. long or the lateral ones 55—57 mm. long. South West Africa:

30. Glumes 1-nerved, the lower shortly bifid with a 5—6 mm. long awn, the
upper one deeply bifid with a 14 mm. long awn from the sinus, the
very fine lateral setulae about 7—8 mm. long, the central part of the
upper glume more or less pilose with long spreading scattered white
hairs, sometimes adpressedly hairy only along the margins, the hairs
often hidden by the margins of the lower glume and easy to overlook.
Culms simple below, branched from the lower and upper nodes, mostly
40—60 cm. high, robust, pale-coloured, with old broad and [lapery
sheaths at the base, culm-nodes tumid and protruding above the annular
sheath-nodes; sheaths shorter than the internodes which are more or
less scabrous, comhionly very distinctly rough and more or less com-
pressed, rather deeply striate and with hyaline mostly inrolled margins,
ligule shortly ciliate, the auricles pubescent-ciliate, those of the few
innovations long-bearded, the collar scabrous; blades flat at the base,
soon becoming involute, nearly glabrous beneath, scabrous on the upper
surface and along the margins, up to 20 cm. long or even longer,
2—4 mm. wide when expanded; panicle exserted, somewhat flaccid
or more or less curved at the summit, with up to 10 cm. long branches
which are more or less drooping or suberect, lower brandies binate,
the upper ones solitary, all naked at the base, axis of the panicle

scabrous, the axils of the branches shortly ciliate-pubescent, the pedicels
very scabrous, subcompressed or subangulous and subclavate at the
tips; spikelets golden-yellow, glumes slightly scabrous on the keels, the
lower one 22 mm., the upper one 82 mm. long, inclusive of the awns;
lemma with the shortly pilose or pubescent, acute, about 2 mm. long
callus, up to 10 mm. long, the body somewhat compressed, not or
scarcely narrowed above, finely punctulate, glabrous and smooth below,
scabrous at the summit, column strongly twisted, 25—32 mm. long,
awns erect, scaberulous, the central one up to 7 cm. long, the lateral
ones about 6V2 cm. long. North Africa: Nubia and the French Sahara. . .
.................Aristida pallida Steudel

Lower glume 3-nerv6d, the lateral nerves short but very prominent and
anastomosing with the midnerve, not bifid at the a;pex, shortly awned
only, the upper glume 1-nerved, bifid at the apex, with a 5 mm. long
awn from the sinus and about 2^/3 mm. long lateral setulae, glumes
without long hairs, quite glabrous.

Caespitose erect perennial with rather few innovations, branched from
the base and from some of the lower nodes, up to 40 cm. long,
commonly shorter, elegant, terete, glabrous and smooth ; sheaths slightly
shorter than the internodes, glabrous and smooth, striate, tight, not
slipping from the stems, ligule a shortly ciliate rim, auricles pubescent,
those of the innovations long-bearded; blades narrow, convolute-
setaceous, glabrous beneath, scaberulous on the upper surface, up to
20 cm. long or those of the innovations much shorter, about 1 mm.
broad; panicle rather few-flowered, narrow, elongate, more or less
interrupted especially at the base, the branches somewhat distant,
rather short and few-llowered, binate or subsolitary at the summit,
strictly erect or adpressed, not rarely all the branches with one
S|)ikelet, the branches geminate, one longer peduncled, the other nearly
subsessile, the pedicels more or less scaberulous, subcompressed, shorter
than the glumes; spikelets yellowish, tinged with brown, glumes
lanceolate, glabrous, the lower long-acuminate, subulate, inclusive of
the 2 mm. long awn about 15—17 mm. long, scabrous on the keel,
the upper one subulate, inclusive of the 5 mm. long awn about
20—24 mm. long, smooth on the keel, the very fine lateral setulae
closely adpressed; lemma smooth, inclusive of the callus 9 mm long,
the callus about 2 mm. long, acute, densely hairy with a sharp, naked
point; column mostly 25-30 mm. long, rarely shorter, strongly twisted,
scaberulous, awns scabrous, about equal, or the central one somewhat

Plants smaller, more dwarf, the glumes and column shorter than
in the type, the lower glume about 11—12 mm. long, the uppei-

Caespitose perennial, culms erect, simple, terete, glabrous, scaberulous,
slightly striate, together with the panicle up to 50 cm. high, 1-noded,\'
the node placed at about 1/8 of the length of the culm from the base
of the plant; sheaths about as long as the internodes or slightly
longer, tight, striate, scaberulous, ligule a ciliate rim, auricles long-
bearded; blades linear, subulate, flat at the base, soon becoming
convolute but not rigid, scarcely 1 mm. broad when expanded,
greenish to glaucous, scaberulous beneath, densely hirtellous on the
upper surface, up to 15 cm. long; panicle very narrow, elongate,
strictly erect, interrupted below, together with tbe awns about 30 cm.
long, the axis terete, striate, scaberulous and laterally grooved, the
branches unequal, binate, the lower primary ones longer, exclusive of
the awns 4—5 cm. long, 2-flowered, naked in lower 1/3 part, the
secondary and upper branches shorter, 1-flowered, shortly pedicelled,
the pedicels angulous and scabrous; spikelets pale-yellow, glumes firm,
strictly erect, unequal, 1-nerved, the lower scabrous, scaberulous on
the keel, 13—14 mm. long, chartaceous, slightly bidentate at the apex,
shortly awned from the smus, the upper one 22—24 mm. long\'
narrower, gradually acuminate and distinctly but shortly awned, the
keel smooth; lemma tubulous, punctulate-scaberulous under a lens,
mottled, about 9—10 mm. long, inclusive of the very acute, pungent,
densely long-bearded about 2\'/2 mm. long callus; column firm, nearly
smooth with scabrous margins, much twisted, awns scabrous, somewhat
unequal, tbe central one up to 7 cm. long, the lateral ones about

Column of awns rather variable in length, but always much shorter than
4 cm., commonly 25—30 mm. long or not rarely shorter and about
22—23 mm. long; upper glume mostly shorter than 2 cm., mostly
15—18 mm. long, rarely slightly longer.

Slender caespitose, erect or geniculately ascending, elegant perennial,
culms simple or slightly branched below, up to 40 cm. high, slightly
compressed, striate and scaberulous; sheaths much shorter than the
internodes, striate, scabrous like the internodes, ligule a ciliate rim,
passing laterally into bearded auricles and a puberulous collar; blades

very narrow, convolute, up to -10 cm. long, acute, somewhat rigid,
mostly erect, slightly scabrous beneath, scabrous and shortly pubescent
on the upper surface; panicle exserted, 10—15 cm. long, very narrow,
more or less interrupted at the base, more dense upwards, with a
slender scabrous rhachis, the branches strictly erect and adpressed
2—3-nate, somewhat distant, scabrous, the lower and longer ones
mostly bearing 2 flowers, the upper ones and. the shorter ones only
1-flowered, the upper branches solitary, the short erect pedicels
scabrous, more or less compressed or angulous, subclavate; spikelets
yellowish or brownish, glumes glabrous or minutely scaberulous or
puberulous, acute, the lower 1-nerved or rarely with an additional
side-nerve, 8—9 mm. long, sometimes up to 12\'/2 mm. long, scarcely
awned, the upper one rigid, convolute, 15—16 mm. long or not rarely
18-20 mm. long, and even slightly longer, very acute, not or scarcely
awned; lemma chestnut, 7—8 mm. long inclusive of the callus, smooth
below, somewhat scabrous at the summit, punctulate under a stronquot;-
lens, the callus densely bearded especially on the margins, very acute^
2 mm. long with a prominent naked point; column strongly twisted\'

long, sometimes up to 65 mm. long. Australia: From West Australia
to Queensland, south to New South Wales.........

32.nbsp;Glumes not awned, obtuse or acute to acuminate, the upper one if shortly

Glumes awned, the upper one always more or less bifid at the apex, the
lateral lobes well-developed, long and fine, rarely the summit of the
upper glume shortly bifid, the lateral lobes less-developed and the
awn from the sinus short..............

Caesi)itose perennial, culms elegant, erect or ascending, glabrous and
smooth, sheathed all along, somewhat branched, the branches panicle-
bearing; sheaths glabrous, shorter than the internodes, the lower
broader, with distinct hyaline margins, the upper ones narrower, ligule
a mimite ciliolate rim, auricles shortly pubescent; blades equally broad
at the base, narrowly involute or setaceous, long-acuminate, scarcely
V2 mm. broad when expanded, about 10 cm. long, glabrous beneath,
scaberulous or shortly hairy on the upper surface; panicle about 10 cm!

long, linear-lanceolate, contracted but somewhat lax and subinterrupted,
shortly exserted or not rarely sheathed at the base by the uppermost
leaf, the axis glabrous, the branches rather thin, binate or subsolitary,
erect, few-flowered; spikelets glabrous, shortly pedicelled, the pedicels
angulous and puberulous, subclavate at the tips, glumes very unequal,
linear-lanceolate, obtuse, the lower 6—7 mm. long, 1-nerved, very
shortly and abruptly mucronate, keeled, the keel scabrous, upper one
1-nerved, 13—14 mm. long, smooth, not keeled, minutely bidentate at
the apex; lemma smooth about 6 mm. long, inclusive of the very acute,
densely hairy, mm. long callus, column glabrous below, scabrous
upwards, about 20 mm. long, strongly twisted; awns about equal or
mostly somewhat unequal, the central one about 5^2 cm. long, the

long, lemma with callus 6 mm. long, awns mostly up to 6 cm. long,
rarely shorter.

. Densely caespitose, rather small, not more than 15 cm. high, with
intravaginal innovations; culms nearly simple, strictly erect or slightly
ascending, scabrous, subterete, slightly striate or grooved laterally,
sheaths glabrous or scaberulous, striate, slightly compressed or subterete,
shorter than the internodes or sometimes as long as or longer, ligule
a short ciliolate rim, auricles long-bearded, collar glabrous; blades
very fine, quite convolute, setaceous or almost fihform, more or less
curved or flexuous, pointed, 5—8 cm. long, or rarely shorter, scabrous
on both sui\'faces; panicle very narrow, iinear-lanceolate, scarcely
branched or not rarely reduced to a simple raceme, about 5—8 cm.
long exclusive of the long awns, sometimes longer than half the length
of the whole plant, the lower branches 2—3-nate, strictly erect or
adpressed, the longer ones 2-flowered, the shorter ones bearing but a
single spikelet, the pedicels scabrous, angulous; spikelets erect, purplish,
glumes glabrous, scabrous on the keels, narrowly linear to lanceolate,
finely pointed, 1-nerved, or the lower one sometimes with very minute
additional nerves, the tips of the glumes sometimes minutely bidentulate;
lemma finely punctulate under a lens, about 0 mm. long, inclusive of
the densely hairy, sharp-pointed. 2 mm. long callus; column always
less than 2 cm. long, mostly 10—15 mm. long or sometimes up to
17—18 mm. long, strongly twisted, the awns very fine, scabrous,

Sheaths with spreading long hairs, blades with long, weak, tubercle-
based hairs.............var. hirsuta Henr.

Glumes not so very unequal, the lower 15—17 mm. long, the upper one
17—19 mm. long, lemma with callus 8—9 mm. long, awns much

shorter, abouth S\'/a—4 cm. long.
Caespitose erect perennial, rather robust but very fragile, pale-glaucousj
culms erect or somewhat ascending, about 30—40 cm. high inclusive
of the panicles, much branched from nearly all the nodes, few-noded,
culm-nodes swollen and protruding above the slightly annular sheath-
nodes, the internodes terete, nearly smooth, slightly or scarcely striate;
sheaths of the lowermost leaves pale or straw-coloured, glabrous and
smooth with hyaline margins, the upper ones tight or not rarely
slipping from, the stems, subterete or subcompressed, slightly striate
and nearly smooth, much shorter than the internodes, mostly only
half the length of them, ligule a short ciliolate rim, auricles pubescent
only, those of the few innovations more or less distinctly bearded;
blades terete, subjunciform, rigid, erect, pale-greenish or glaucous,
narrowed to a subpungent tip, up to 15 cm. long or those of the
lateral branches much shorter and sometimes only 3 cm. long, about

1nbsp;mm. broad when e.xpanded, glabrous beneath, densely hirtellous on
the upper surface; panicles rather dej)auperate especially those of the
lateral branches, exserted, contracted but lax and more oi- less
interrupted, 10—15 cm. long, the lateral ones much shorter and
narrower, axis ofthe panicle terete or subcomi)ressed, slightly scaberulous,

or distinctly ciliate-pubescent, all the branches bearing but a sin\'de
s})ikelet, the longer ones with a pedicel nearly as long as the glumes
the other ones nearly subsessile, the pedicels angulous or slightly
compressed above, scaberulous and subclavate at the tips; spikelets
pale or greenish, erect, glabrous, the glumes lanceolate, acuminate,
keeled, 1-nerved, narrowed above but scarcely awned, more or less
obtuse at the very tip, the upper glume smooth on the keel; lemma
linear-lanceolate, nearly smooth, rounded at the base and rather
suddeidy contracted into the acute, densely, but shortly hairy, abont

2nbsp;mm. long callus, the hairs not sin-passing the very base of the lemma
which is about 8—9 mm. long inclusive of the callus, the body
gi-adually narrowed above into the 10—13 mm. long, strongly twisteii,
lirm cohnnn, awns filiform or capillary, more or less spreading,
scaberulous, the central one 31/2—4V2 cm. long, the lateral ones \'/a cm.

35.nbsp;Upper glume very shortly bifid at the apex, with short lateral lobes and

Upper glume more or less, mostly deeply bifid at the apex, with long,
narrow, lateral lobes and a long awn from the sinus.......37.

7 mm. long, half as long as the upper one, the lemma with the densely
hairy, acute callus, up to 7 mm. long, the slightly twisted scabrous
column 12 mm. long.

Perennial, from a thick rootstock, much branched from the base and
from tbe lower nodes, up to 1 meter high, inclusive of the long, drooping
panicle; culms erect, many-noded, the branches panicle-bearing, inter-
nodes about equal, terete, striate, somewhat pruinose, the lowermost
naked, subterete or flattened laterally; lower sheaths brown, shorter
than the internodes, without blades, the upper ones longer than the
internodes, the culm-nodes very tumid, protruding above the brown
sheath-nodes, upper sheaths slightly compressed, striate, finely hirtellous
between the nerves, ligule a short ciliolate rim, auricles rather long-
bearded; blades narrow, convolute, flat at the very base, up to 30 cm,
long, erect, gradually narrowed to the long setaceous point, scabrous
on both surfaces, blades of the upper leaves much shorter; panicle
very lax about 30 cm, long, branches at first erect, afterwards spreading
and drooping, binate or semi-whorled, up to 15 cm, long, naked at
the base, bearing at the summit erect branchlets with more or less
adpressed spikelets, branches and pedicels scabrous, the latter shorter
than the glumes or the terminal ones as long as or longer, subtrique-
trous, tips slightly clavate; spikelets brownish, glabrous, glumes very
unequal, scabrous on the keel, the upper narrower, 1-nerved, smooth
on the keel, about 15 mm. long, slightly bifid at the summit, with a
short awn from between the small lobes, callus about I\'/g mm. long witb
an acute naked point, lemma slightly swollen, narrowed upwards, scabrous
especially in upper part, column very fine; awns about equal, the
lateral ones about 6 cm, long, the central one somewhat longer, up

Culms elegant, about 1 mm. thick, many from a tuft; lower glume 1-nerved,
about 10 mm. long, more than half as long as the upper one; lemma
with the densely hairy, very acute callus, 10—11 mm. long, the strongly
twisted scabrous column 16—20 mm. long.

Densely caespitose, up to 60 cm. high perennial, inclusive of the about
15 cm. long panicle, culms strictly erect, 3—5-noded, branched from

nearly all the nodes, the branches elongate and panicle-bearing, inter-
nodes about equal, terete, smooth, slightly striate, the lowermost naked,
the sheaths delapsed, the upper ones longer than the sheaths, culm-nodes
tumid, protruding above the annular dark sheath-nodes; sheaths some-
what compressed, striate, glabrous, hgule obsolete, a minute ciliolate ^
rim, auricles puberulous or ciliolate; blades very narrow, fdiform,
convolute throughout, erect or somewhat spreading, glabrous beneath,
scabrous on the upper surface, very acute, those of the innovations up
to 20 cm. long, those of the upper leaves much shorter, 3—7 cm.
long; panicles narrow, spiciform but not dense, more or less inter-
rupted, with erect few-llowered branches, the branches 2—3-nate,
bearing 2 or commonly but a single spikelet, branches and pedicels
smooth or slightly scaberulous, the pedicels about 6 mm. long; spikelets
pale or greenish, glabrous, glumes 1-nerved, acute or shortly awned,
the upper one about 18 mm. long, lemma nearly glabrous with a
2V2 mm. long callus; awns capillary, about equal, 50 mm. long or the
central one 55—60 mm. long. South Africa: Transvaal to Delagoa Bay.
...............Aristida graciliflora Pilgor

Glumes scabrous, the upper one moreover with scattered long hairs on the
back at the middle or only near the margins.

Culms simple below, branched from some of the lower and upper
nodes, up to 60 cm. high, glaucous, dark-coloured or purplish; sheaths
at the base broad, scale-like, papery, many-nerved, straw-coloured,
with hyaline margins, those of the culm-leaves shorter than the slightly
striate, minutely scaberulous or smootli internodes, slipping from the
stems, ligule a minute ciliolate rim, auricles densely ciliate; blades
convolute, filiform, glabrous beneath, scabrous on the upper surface
and along the margins, 10—20 cm. long; panicles strictly erect, exserted,
10—15 cm. long, narrow, contracted, purplish, the lower branches sub-
fascicled, the upper binate, the longer branches naked at the base,
bearing 2—5 spikelets, the shorter branches 1—2-llowered, axis of
panicle nearly smooth, axils not bearded, minutely puberulous, branchlets
and pedicels scaberulous, the tips of the pedicels subclavate; glumes
minutely pubescent or scabrous all over, 1-nerved, the nerves hispi-
dulous, lower one not bifid, inclusive of the 2—2 72 mm. long awn,
up to 16 mm. long, the upper about as broad as the lower one, deeply
bifid at the apex, inclusive of the 10 mm. long awn, up to 26 mm.
long, the lateral lobes very fine, 3—4 mm. long, central part of the
upper glume with adpressed white hairs near the margins, the hairs
deciduous; lemma punctulate under a strong lens, about 12 mm. long

inclusive of the 2 mm. long, acute, hairy callus, the column strongly
twisted, 18—20 mm. long; awns erect or slightly spreading, nearly

Plants not robust, elegant, with slender, thin culms, mostly not over
15 cm. high.....................

39. Lower glume rather broad, with the 4 mm. long awn up to 13 mm. long,
upper glume with a deeply bifid apex, inclusive of the 4 mm. long awn
up to 17 mm. long, the lateral lobes about 2V2 mm. long; lemmaquot;with
the callus 10 mm. long, the awns more than 45 mm. long, mostly up
to 50 mm. long or slightly longer.

Robust, loosely caespitose perennial, simple below, branched from the
lower and upper nodes with old, glabrous, scale-like sheaths at the
base; sheaths shorter than the glabrous, nearly smooth internodes,
slipping from the stems, glabrous, striate, with hyaline margins, culm-
nodes tumid, protruding, ligule a ciliate membrane, auricles long-bearded;
innovations short, the sheaths with long hairs at the summit, the
auricles and collar more densely hairy, blades of innovations shorter
than those of the culm-leaves, the latter convolute and filiform or flat
at the very base, acute, up to 20 cm. long, glabrous and smooth beneath,
scabrous on the upper surface; panicle about 20 cm. long, erect,
somewhat contracted but rather loose, the branches somewhat spreading,
axis glabrous, nearly smooth, the axils of the branches without hairs;
glabrous, branches binate or the uppermost ones solitary, jiaked at the
base, the longer ones bearing 3—5 spikelets, the shorter ones with 1—2
flowers, branchlets and subclavate pedicels slightly scabrous; lemma
smooth, the densely hairy acute callus about 2 mm. long, the column
loosely twisted, scaberulous, awns scabrous, erect or somewhat spreadinfr.
Africa: Southern Tunis and Senegambia to Gold Coast, Togo and Kamerurt
............. Aristida longillora Schumacher

Lower glume narrower, inclusive of the 2 mm. long awn up to 9 mm. long,
upper glume not so deeply bifid, the lateral lobes about 1 mm. long|
inclusive of the 3 mm. long awn from the sinus, about 14 mm. long;
lemma with the callus 7 mm. long, the awns less than 40 mm. long, mostly
35 mm. long or slightly longer.

Caespitose, 75—90 cm. high, strictly erect perennial, culms many in a
tuft, branched nearly from all the nodes, terete or sliglitly compressed ;

lower sheaths reduced to broad yellow scales, upper ones shorter than
the glabrous, nearly equal internodes, slipping from the stems, glabrous
and smooth, culm-nodes swollen, protruding, ligule a very short, scarcely
ciholate rim, auricles glabrous or minutely puberulous; blades involute,
narrow, up to 30 cm. long, filiform, erect, acute, subpungent, glabrous
beneath, scabrous on the upper surface and along the margins; panicles
narrow, subspiciform, shortly exserted, 20—25 cm. long, with smooth
axis and axils, branches filiform, erect, somewhat distant, the lower
ones up to 5 cm. long, the upper ons gradually becoming shorter,
2—3-nate, the longer ones naked at the base and bearing 3—5 spikelets,
the shorter ones few-tlowered, the lateral flowers shortly pedicelled,
the other ones with pedicels as long as the glumes, the branchlets and
pedicels scabrous; glumes narrow, the lower scabrous on the keel;
lemma smooth, punctulate under a strong lens, the densely but shortly
hairy callus, about 2 mm. long, the strongly twisted scabrous column
10—12 mm. long, the awns scaberulous, erect or slightly spreading.
South East Africa: Mozambique................

lt; 3

■

\'I

Many authors had already observed that there are Aristidas where tlie awns are
articulated with the twisted column just below their branching-point. Trinius and
Ruprecht described Aristida repens, A. subspicata, A. mutabilis, A. 7neccana and
A. barbicollis, in their desci-iptions of Aristida congesta R. amp; S. and A. setifolia

H.nbsp;B. K, the same character of the articulation is mentioned. Andersson saw this
character when he studied and described the Aristida-species from the Galapagos Islands.

A name for this section was given by Ciiiovenda in the year 1912 but no des-
cription of the section was given by him, but he used the name at the head of the
description of his ^ma\'da as/rocMa. The long and very accurate description of this
curious grass, leaves no doubt that Ciiiovenda\'s species is a member of the group
of Aristidas where the summit of the column is articulated with the awns. Chiovenua
says under A. astroclada: „Gluma llorens apice sensim in columnam laxe intortam
(iliformem scabram, apice articulatam attenuata.quot;

Although the articulation observed in all the species of this group is very distinct,
the awns are not always disarticulating at maturity. The place of the rupture
consists of a special tissue and is always indicated by a more or less developed
nodule. Recause the awns are not spotitaneously articulating, many authors described
species belonging to this .section as having no articulation. Without the type s[)eci-
mens it is in such cases impossible to place such species in one of the sections
The South American Aristida Doclliana is allied to A. setifolia and therefore once
more studied by me, I found that an articulation is present at maturity and the
species is therefore placed in the section Pseudarthratherum. In the keys 1 have
howevei- mentioned it also under the section Chaetaria.

Hitherto there are known about 21 species of this section. The continent of South
America has but 2 species and 5 species occiu^ only on the Galajiagos Islands, all
the other ones are found in Africa, some of them also in Arabia, one e.xtending to India.

I.nbsp;Panicles densely contracted, spike-like, the branches very short, spikelet-

bearing from the base, sometimes slightly interrupted or with 1 — 2
peduncled additional false spikes at the base, rarely not dense and
spike-like but narrowly linear and more or less interi-upted, with
llexuous subsecund branches, but always spikelets bearing from the base. 2.

Panicles lax and open or composed of more or less peduncled false spikes,
sometimes loosely contracted, the long branches erect and adpressed,
but always naked below and never dense and spike-lrke......12.

2. Sheaths glabrous or scabrous, sometimes with a very short pubescence,
but never silky-villous..................

Sheaths conspicuously silky-villous with white, spreading hairs, except
near the base, covered with more densely tufted hairs near the summit.
Annual, with several slender, erect or ascending, 3—6-noded, simple or
sparingly branched, slightly puberulous, terete culms, up to 35 cm. high;
sheaths shorter than the intei-nodes, compressed, striate, tight or more
or less slipping from the stems, culm-nodes but slightly swollen, scarcely
protruding above the glabrous annular sheath-nodes, ligule laciniately
ciliate, auricles bearded, collar pubescent or smooth; blades glaucous,
flat, thin, linear, 5—12 cm. long, 21/2-3 mm. broad, convolute at the
summit, awn-pointed, finely pubescent and slightly scabrous or liispi-
dulous on both surfaces; panicles exserted, 4 — 7 cm. long, scarcely

1nbsp;cm. in diameter, subspicate, interrupted at the base, axis pubescent,
branches solitary, densely fascicled, sessile, scabrous; glumes slightly
unequal, lineai\'-lanceolate, attenuate, shortly awned. up to 8 mm long,
the lower 3-nerved, puberulent on the back, or becoming glabrous,
the nerves very scabrous, rather abruptly narrowed into the nearly

2nbsp;mm. long awn, somewhat rounded at the tip when expanded, witliout
the awn about 4 mm. long, upper glume narrower, 1-nerved, slightly
pubescent on the back and scabrous on the keel, deeply bifid at the
apex, «-ith acute lobes and a 1\'/., mm long, scabrous awn from the
sinus; lemma thick, ovate, glabrous below, scabrous upwards, rather
suddenly narrowed into the very scabrous, scarcely twisted beak, together
with the densely hairy, about Vi quot;nn. long, acute callus, up to 5 mm.
long, the scabrous awns moi-e or less spreading, equal or mostly unequal,
the central one 9—15 mm , the lateral ones 5—0 mm. long. Galapagos

3. Culms densely caespitose or but slightly ascending; panicles dense and
spike-like; column always well-developed; glumes acute, long-awned,

Culms prostrate and rooting at the nodes, ascending upwards; panicles
linear, interrupted, l ather loose. nots[)ike-like; column very short, scarcely
developed, very slightly twisted; glumes shortly awned only.
Caespitose decumbent annual, much branched and prostrate and creeping
at the base, stoloniferous, rooting at the lower nodes and sending up
sterile tufs of leaves or erect lloi\'iferous branches, culms many-noded,
terete, slightly striate, smoother minutely scaberulous; sheaths slightly
striate, glabrous, compressed, slipping from the stems, the u[)perones
tight, shorter than the internodes, ligule and auricles densely ciliate,
the latter more or less bearded, collar glabrous; blades narrowly linear,
llaccid, scarcely l\'/^ mm. wide, 10-15 cm. long, or the lower ones

much shorter, flat or inrolled and convolute upwards, ending in a
setaceous point, glabrous beneath, scabrous or hirtellous on the upper
surface, the inrolled margins not thickened, bluish-green; panicles
exserted, 10 — 15 cm. long, contracted, linear, with Ilexuous or subsecund,
solitary, up to 3 cm. long, erect branches, spikelets bearing from the
base, axis striate, angulous and scaberulous, spikelets nearly sessile or
shortly pedicelled, the pedicels scabrous; glumes about equal, 1-nerved,
narrowly lineai\', pale coloured or greenish, the lower scabrous on the
keel, shortly awn-pointed, about 7 mm. long, the upper one .scabrous
only on the keel upwards, slightly and abruptly bilid with a mucro
or short awn from the sinus; lemma tubulous, keeled, glabrous and
punctulate below, scaberulous above, the keel very scabrous, slightly
narrowed and beaked only, minutely twisted, the callus about V\'» mm.
long, subobtuse, densely and long-bearded, the body of the lemma
about 5 mm. long, articulation below the awns very distinct, awns
slightly spreading or divaricate or suberect, scabrous, somewhat une-
qual, the central one 9—-10 mm. long, the lateral ones about 7 mm.

4. Lower glume mostly glabrous or scaberulous only, with an awn much shorter
than the glume; lemma linear-cylindric, gradually passing into the
twisted column, glabrous, scabrous or even tuberculate, but not with

Lower glume hispidulous, with an awn nearly as long as the body of the
glume; lemma oblong-cylindric, more abruptly narrowed into the column,
smooth, densely punctulate under a lens, pubescent at the striate summit.
Tufted, simple or scarcely branched, firm, rather robust, probably
annual plant, erect or somewhat geniculate at the base, culms including
the panicles about 35 cm. high, 2—3-noded, terete, slightly striate
scabrous, especially below the nodes, more or less pubescent; sheaths
tight, sti\'iate, very scabrous, somewhat compressed, about half as lon^\'
as the internodes, ligule a dense ciliolate rim, auricles long-bearded
collar glabrous; blades long, Hat or the margins inrolled, acute, u|) to
3 mm wide, up to 20 cm. long or those at the base of the [)lant
commonly much shorter, prominently nerved, the midnerve keeled
beneath, glabrous on the lower surface, very scabrous and hirtellous
on the upper surface, ending in a setaceous point, the margins very
scabrous and not thickened; panicles shortly exserted or not rarely

narrowed at the base, obtuse at the top, up to 2 cm. wide including
the awns, very dense, not or scarcely interrupted below, the peduncle

liirsiite or hirtellous, axis scabrous; spikelets pale greenish, densely
congested on the short erect branches, with very short or nearly sessile
hispidulous pedicels; glumes 1-nerved, unequal, the lower very scabrous
on the keel and pubescent-hispid on the back, about 4 mm. long,
lanceolate-ovate, acuminately narrowed into the scabrous awm, the
upper one scabrous on the keel, the margins inrolled above, deeply
bifid at the summit, the lateral setulae very acute and about 1 mm.
long, awned fi\'om the sinus, the . awn 2—3 mm. long, the total length
of the glume about 9 mm.; lemma with a densely long-bearded, 1/2 mm.
long, subobtuse callus, the body fusiform, densely punctulate and striate
at the summit, slightly keeled, about 3 mm. long, pas.sing into a very
scabrous, strongly twisted column, about as long as the body; awns
slightly spreading and somewhat curved at the base, erect, very scabrous,

Lemmas granular, densely tubercled in upper part, quite smooth only in
lower 1/4 part.

Caespitose, robust, simple, erect, 80—90 cm. high perennial with few-
innovations, culms 3—4-noded, slightly compressed, glabrous, smooth,
striate, culm-nodes protruding above the dark annular glabrous sheath-
nodes; sheaths glabrous and smooth or slightly scaberulous, striate,
compressed, tight, shorter than the internodes, ligule a densely ciliate
rim, auricles pubescent and with some long hairs, collar with a dark
triangular spot, pubescent and more or less bearded laterally, the hairs
deciduous; blades linear, acuminate, U[) to 20 cm. long, 2—3 mm. broad
at the Hat base, convolute, glabrous and smooth beneath, liirtellous
and scabrous on the upper surface and along the not thickened margins,
ending in a very scabrous obtuse point; panicle exserted, with a glabrous
or slightly scabrous peduncle, contracted, linear, elongate, erect, dense
and spike-like, interrupted only at the very base, about 20 cm. long,
together witii the awns up to 3 cm. wide, axis terete and slightly
scaberulous below, visible only at the base of the panicle, branches
solitary, much divided nearly from the base or quite sessile, the branchlets
and pedicels scabrous, very short and densely fascicled, the axils
pubescent or smooth; spikelets erect, linear, slightly scaberulous, glumes
1-nerved, the lower very scabrous on the keel, including the awn, which
is about as long as the glume, 9—10 mm. long, upper glume slightly
scabrous only on the keel above, including the about 3 mm. long awn,
11 — 12 mm. long, the apex bifid, the acute lobes about I mm. long;
lemma including the 1 mm. long, shortly but densely hairy, acute callus.

about 6 mm. long, narrowed above into a scabrous, twisted. 4—6 mm.
long column; awns about equal, scabrous, erect or slightly spreading,
20—25 mm. long. South West Africa: Ovamboland to Rhodesia. . .
.............. Aristida alopecuroides Hackel

6.nbsp;Sheaths bearded at the junction with the blades, tbe auricles and collars

7.nbsp;Perennial, more than 15 cm. high, up to 00 cm. long plants, with equal or sub-

Annual, scarcely 40 cm. high or mostly lower plants, with unequal inter-
nodes, the two nodes below the panicle approximate, the upper leaves
enclosing the base of the panicle.

Densely caespitose. forming small bunches, culms erect or geniculately
ascending, striate, glabrous, few-noded, nodes glabrous; lower sheaths
very short, witb short blades, pale, striate, compressed, glabrous and
smooth witb hyaline margins, upper ones as long as or longer than the
internodes, broad above, glabrous or minutely scaberulous, striate,
dark-green or tinged with purple, with broad margins, ligule a short
ciliolate rim, auricles densely bearded, the collar sometimes laterally
bearded with more or less rellexed hairs; blades 4—6 cm long, the
upper ones somewhat shorter and overtopping tbe panicle, linear,
narrow, up to 2 mm. broad when expanded, more or less spreading,
plicate and involute, prominently sulcate-striate, scabeiulous beneath,
shortly hairy or hirtellous on the upper surface, ending in an obtuse
rathei- tliick point; panicle sheathed by the upper leaves, very shortly
peduncled, ovate-oblong, very dense, 3—H\'/z cm. long, about I\'/j cm.
broad, with short, densely fascicled branchlets and spikelets, the branches
and subclavate pedicels scaberulous; spikelets pale green, tinged some-
times with purple, dark yellow at maturity; glumes unequal, narrowly
lanceolate, i-nerved, shortly awned, hispidulous on tbe keels, the lower
one 6—7 mm, long, gradually narrowed into the awn, the upper one
10 mm. long, bifid at the a[)ex with acute lateral setae and a 2 mm,
long awn from the sinus; lemma with a densely hairy, very acute,
up to 1 mm, long callus, 4—5 mm. long, smooth or minutely scaberulous
at tbe summit, narrowed into a 2^2 mm. long, twisted column, awns
very line, minutely scabrous, subequal, somewhat divergent, about
20 mm. long. South West Africa: Great and Little Namaqualand,

8. Glumes about equal or very slightly unequal, lower glume smooth or
scabrous, the upper one with an awn from a very prominently bifid

3nbsp;mm. long awn from a minutely bifid or slightly bidentate apex;
lemma nearly smooth.

Erect, simple, glabrous up to 60. cm. high perennial, culms sheathed
all along, glabrous; sheaths glabrous, striate, shorter than the inter-
nodes, ligule a minutely ciliate rim, auricles bearded, the collar with
more or less spreading hairs; blades convolute-filiform, acuminate,
10—20 cm. long, narrowly linear, glabrous beneath, scaberulous on the
upper surface; panicle long-exserted, about 20 cm. long, contracted,
dense and spike-like, linear-oblong, somewhat interrupted at the base
with solitary scabrous branches, the lower ones naked at the base over
a short distance, the upper ones sessile, much divided and spikelets
bearing nearly from the base, all the branches erect and adpressed,
the branchlets and pedicels very short, scabrous and densely fascicled;
spikelets densely congested at the ends of the branchlets, subsessile
or shortly pedicelled, linear or linear-lanceolate, greenish, tinged with
purple, glumes 1-nerved, glabrous, the lower 4V2 mm. long, gradually
narrowed into the 2 mm. long scabrous awn, scabrous on the keel,
the upper one glabrous and smooth on the keel, not or scarcely bifid
at the apex, gradually narrowed into the about 3 mm. long, scaberulous
awn; lemma including the up to I\'/g mm. long, very acute shortly
hairy callus, 5—6 mm long, linear-tubulous, quite smooth or very
slightly scaberulous only at the summit just below the column, gradually
passing into the elegant, twisted, about 4 mm. long column, awns very
fine, somewhat spreading, scaberulous, nearly equal, up to 2\'/2 «\'m.

9. Column of awns short, much shorter than the body of the lemma, a slightly
twisted scaberulous beak only; lower glume scabrous above and along
the nerves, 3-nerved, callus obtuse.

Caespitose rather robust perennial, culms erect with the panicles 10—12
dm. high, simple, glabrous, slightly striate, terete, 5—6-noded, nodes gla-
brous; sheaths shorter than the internodes, |,dabrous, bearded at the collar
with long reflexed hairs, ligule obsolete, minutely ciliate, auricles
pubescent and more or less rellexed-bearded; blades from a flat base
gradually acuminate, laxly convolute above, the upper ones involute,
up to 30 cm. long, rigidulous, glabrous beneath, scabrous on the upper

surface and along the margins, finely nerved, the nerves not very
prominent; panicle dense more or less contracted, up to 25 cm. long,
2—3 cm. broad with a terete axis, branches solitary, 5-6 cm. long,
much branched from the base with adpressed branchlets with densely
imbricate spikelets, branchlets and short subclavate pedicels scabrous;
spikelets very shortly pedicelled, pale, glumes somewhat unequal, the
lower one about TVj mm. long, 3-nerved, scaberulous in upper half
part, with scabrous nerves and keel, linear-lanceolate, rather abruptly
narrowed into the scabrous about IV2 mm. long awn, upper glume
i-nerved, narrower, keel smooth, distinctly bidentate at the apex with
a 2 mm. long awn from the sinus, up to 10 mm. long; lemma 7 mm.
long, linear or subfusiform, punctulate nearly all over and scaberulous
at the summit with a subobtuse, long-bear.led, about 1 mm. long callus
and a scabrous about 1 V2 mm. long, twisted column, articulation very
distinct as a nodule below the branching-point of the erectly spreading
nearly equal, scabrous, 16-20 mm. long awns. South West Africa:

Column of awns long, mostly as long as the body of the lemma, strongly
twisted; lower glume 1-nerved, smooth except the keel, callus acute.
Erect, caespitose peremiial, culms 40—60 cm. high, many-noded,
branched nearly from all the nodes; lower sheaths lax, pale, slightly
striate, upper ones com[)ressed, keeled, striate, scabrous, sometimes with
a few long hairs above, shorter than the internodes, ligule very short,
obsolete, densely ciliolate, auricles bearded with refiexed hairs, collar
pilose; blades Hat at the base and about 2 mm. broad, convolute
upwards, narrowly linear, obtuse, 4—5 cm. or sometimes up to 10 cm.
long, glabrous and smooth beneath, scabrous on the upper surface,
finely nerved; panicle long-exserted, dense, spiciform, interrupted at
the base, 7—9 cm. long, about 1 cm. wide with a glabrous rhachis,
branches solitary, scarcely 1 cm. long, much divided from the base,
sometimes the lower branches more or less peduncled, the upper ones
always subsessile and spikelets bearing from the base with adpressed
branchlets and densely fascicled spikelets; spikelets nearly sessile or
very shortly pedicelled, glabrous with pubescent pedicels, glumes linear-
lanceolate, subequal or slightly unequal, both 1-nerved, lower glume
8\'/^ mm. long, acute, awned, the awn scabrous, the keel very scabrous,
u[)pcr glume about 10 mm long with a smooth keel, distinctly bilid
at the apex, awned from the sinus; lemma glabrous below, very
scabrous in upper half, the body inchiditig the acute densely hairy
about I mm. long callus, about 4V2 mm. long, fusiform or ovate-

lanceolate, narrowed into the scabrous, twisted, about 4 mm. long-
column, the articulation distinct; awns subequal, erect or erectly-
spreading, scabrous, about 20 mm. long. North P:ast Afrilca: Eritrea.
.............Aristida clytrophoroides Chioveiida

10. Lemmas rough, very distinctly and densely scabrous-hispid or tuberculate
in lines in upper half part, the lower part glabrous. African, perennial

Lemmas smooth, under a strong lens minutely and densely punctulate all
over, never scabrous-hispidulous or tuberculate.

Densely or laxly caespitose perennial, not rarely llowering the first
year and apparently annual, with rathei- few innovations, culms simple
or sparingly branched from some of the nodes, erect or more or less
geniculate at the nodes, 2- 3-noded, up to 50 cm. long including the
panicles, glabrous or more or less scabrous below the nodes, terete,
slightly striate, the lower internodes more densely scabeiulous or
subpubescent; lower sheaths more or less flabellate, gaping at the
summit, with overlapping lower margins, slightly striate, somewhat
keeled, more or less scaberulous or puberulous above, upper sheaths
tight, striate-sulcate, distinctly but slightly pubescent at the summit,
with hyaline margins, half as long as the internodes, ligule a minute
ciliolate rim, auricles bearded, especially those of the innovations,
collar smooth; blades narrow, hnear, scarcely 1 mm. broad, sometimes
Hat at the base, convolute-filiform, very acute but not pungent, erect,
those of the innovations convolute throughout, up to 10 cm. long, mostly
shorter, smooth or slightly scaberulous beneath, scabrous or shortly
pilose on the upper surface; panicle more or less exserted or at first
sheathed by the uppermost leaf, the peduncle scaberulous and distinctly
pubescent at the summit below the inHorescence, interrupted at the
base or over the whole length, spike-like, mostly 6—9 cm. long,
oblong to linear-cylindric, thyrsiform, axis subterete or angulous,
scabrid-pubescent, branches solitary, sessile, much divided and spikelet-
bearing to the base, the branchlets and short pedicels scabrous-
hirtellous; spikelets subsessile, glumes unequal, lanceolate to linear-
lanceolate, the lower gradually passing into the scabrous up to 3 mm.
long awn, about 7 mm. long, very scabrous on the keel and sometimes
minutely pubescent on the margins, 1-nerved, commonly with one very
distinct additional side-nerve, the upper glume narrower, 1-nerved,
smooth on the keel below, scabrous on the keel upwards, bifid at the
summit, including the 3 mm. long awn from the sinus, up to 9 mm.
long; lemma smooth, including the long-hairy, subobtuse about mm.
long callus and the twisted about 4 mm, long column, up to 8 mm.

long, ovate-oblong to oblong; awns scabrous, 12 mm. long, or tbe central
one up to \'15 mm. long, more or less spreading, slightly contorted and
curved in a loose spiral at tbe base. South America: Galapagos Islands.
.............Aristida siibspicata Trin. et Rupr.

11. Upper glume deeply bifid at tbe apex with two long, very acute, about
2 mm. long lateral setae and a 2\'/2 mm. long awn from the sinus.
Densely caespitose perennial with many short innovations, culms simple,
erect oi- geniculate and ascending, 20—30 cm. high, striate, subcom-
pressed, 2—3-noded, nodes glabrous; sheaths compressed, the lower
ones with broad hyaline margins, striate, glabrous, much shorter than
the internodes, ligule a shortly ciliolate rim, auricles densely pubescent,
collar glabrous; blades veiy narrow, those of tbe culms 5—0 cm. long,
erect or spreading, those of the innovations shorter and curved, all
tbe blades involute-setaceous with an acute point, glaucous, glabrous
beneath, densely shortly pubescent on the upper surface, many-nerved,
the margins somewhat thickened; panicle spiciform, 0—7 cm. long,
including the awns, \'1-2 cm. broad at the summit, axis nearly smooth,
branches solitary, divided nearly from tbe base, branchlets densely
fascicled with scaberulous or puberulous pedicels; spikelets glabrous,
o^reenisb-purple, glumes narrowly linear-lanceolate, 1-nerved, slightly
unequal, the lower scabrous on the keel, including the 1 mm. long
scabrous awn, 6—7 mm. long, the upper one smooth on tbe keel,
including the awn about 8 mm. long; lemma smooth below, scabrous
above, together with the densely hairy, l mm. long, veiy acute callus
and the 4 mm. long, scabrous twisted column, up to 8 mm. long,
linear-tubulous, gradually narrowed above; awns about equal, \'15 mm.
long, erect or somewhat spreading, scabrous. North Africa: Tunis. .
.................Aristida tuiietaiia Cosson

Upper glume not deeply bifid at the apex, the acute lateral setae scarcely
1 mm. long, mostly much shorter and sometimes not very distinct,
with a scarcely 2 mm. long awn from the sinus.
Densely tufted glabrous perennial, with few innovations, culms simple
or branched from some of the lower nodes, slender, rather wiry, terete,
slightly striate, smooth, mostly erect or geniculately ascending, compressed
below, up to 60 cm. high, mostly shorter and not rarely only about
15 cm. long, 3—4-noded, the nodes glabrous; sheaths compressed,
the lower ones jiale, the margins more or less overlapping at the base,
gaping above, the upper ones tight, striate, smooth or scaberulous
between the nerves, much shorter than the internodes, ligule a
ciliolate short rim, auricles pubescent, collar glabrous; blades very

narrow, acute with a subobtuse tip, up to 15 cm. long or those at
the base of the culms much shorter, sometimes much reduced and
only a few cm. long, those of the innovations mostly about 10 cm.
long, folded or convolute, rather rigid and more or less curved
sometimes flat at the very base, smooth beneath, scabrous-hispidulous
on the upper surface, the margins not thickened, light green or
glaucous; panicle dense, spike-like but commonly interrupted and
sometimes with 1—2 shortly peduncled more or less spreading lateral
false spikes, variable in length, mostly 5—10 cm. long and rarely up
to 15 cm. long, at first shortly, at maturity long-exserted, axis sub-
terete, slightly scaberulous, branches solitary, nearly sessile, much
divided from the base, the branches and pedicels slightly scaberulous
and somewhat compressed, very short, the spikelets densely fascicled,
purplish; glumes unequal, glabrous, the lower lanceolate, somewhat
abruptly passing into the scabei-ulous about 1 mm. long awn, slightly
scaberulous on the keel, up to 8 mm. long, the upper one nari-ower,
linear, quite smooth on the keel, including the awn up to 10 mm.
long; lemma tubulous, including the very acute, hairy, about 1 mm.
long callus and the twisted 3—4 mm. long column up to 9mm.long;
awns more or less divergent, fine, scabrous, slightly unequal, sometimes
only 12 mm. long, mostly longer and 10-18 mm. long. South Africa:

Very robust up to 80 cm. high, with a 20-25 cm. long panicle,
which is interrupted at the base, blades of culms and inno-
vations very long, up to 20 cm., spikelets longer than in the
type, lower glume together with the 4 mm. long awn, 9 mm.
long, upper one inclusive ofthe 4 mm. long awn about 12 mm.

Column of awns straight not twisted, scabrous, very short, scarcely 2 mm.
long; glumes equal.

Culms erect, subgenicnlate or ascending, branched fi-om the lower
nodes, culm-nodes slightly swollen and protruding above the sheath-
nodes, with one to several, short, spreading, 1-noded branches, sheathed
all along and panicle-bearing; sheaths glabrous, slipping from the stems,
ligule a short ciliolate rim, auricles more or less ciliate, collar smooth -
blades narrow, linear, very acute, convolute, 3—5 cm. long, scarcely

nerved and puberulous on the uppei\' surface; panicles of two kinds,
very diiferent in form and very unequal, those of the lateral branches
short, with mostly erect or adpressed short branchlets, the panicle at
the end of the culm long-exserted, effuse, very lax, pyramidal, with
straight or Ilexuous rhachis, 10—15 cm. long, tlie scabrous branches
solitary, distant, spreading, tlexuous or straight, filiform, 5—6 cm. long,
naked at the base over about 3 cm., bearing at the summit adpressed
clusters of nearly sessile spikelets, the pedicels scabrous and slightly
thickened; spikelets yellowish, glumes linear-lanceolate, both about
6 mm. long, the lower 1-nerved, sometimes with an additional sidenei\'ve,
very scabrous on the keel and scabei\'ulous on the back, gradually
acuminate, shortly awned, the upper one glabrous, 1-nerved, distinctly
bifid at the apex with a short awn from the sinus, scaberulous on the
keel; lemma fusiform, glabrous, minutely pinictulate, scabrous at the
summit, gradually passing into the very rough, perfectly straight
column, including the pubescent, subacute, about 3/4 mm. long callus
and the column, up to 0 mm. long; awns very line, scabrous, suberect,
subequal, 10—13 mm. long. West Africa: Upper Guinea, Nigei\'ia. . \'
...............Aristida iiigritiana llackcl

Densely caespitose strictly erect perennial, culms 3—4-noded with
rather long internodes, simjile or sparingly branched from the middle
nodes, terete, glabrous or scabrous especially below the nodes, culm-
nodes swollen and protruding above the annular sheath-nodes, up to

sti\'iate, glabrous or minutely scaberulous, shorter than the internodes
slipping from the stems or the upper ones tight, ligule a rim of Ionquot;
hairs, auricles ciliate, the margins of the sheaths ciliolate near the
mouth, collar smooth; blades lax, erect or more or less spreadino- Hat
at the base, convolute above, up to 2\'/2 mm. wide when expanded
HHform, Die lowej- blades mostlvshorter and about 10 cm. long, the tipper
ones not rarely up to 30 cm. long and sometimes Hat over a loiiquot;\'
distance, glabrous beneath, densely and shortly pubescent on the upper
surface with glabrous not tliickened margins, those of the innovations
convolute throughout and ending in a long setaceous point; panicle
pale-greenish, yellowish at maturity, li near-oblong to ovate-obloiiquot;quot; in
outline, pyramidal, long-exserted or at first sheathed at the base by
the uiipermost leaf, axis terete, striate, sc.iberulous, branches solitary,

erectly spreading, distant, shortly peduncled, naked at the base for
about 1 cm., the upper ones shorter peduncled to subsessile, much
divided with very short branchlets, the clustered spikelets at the ends
of the branches forming 4—5 cm. long false spikes, the upper ones
gradually shorter, the branchlets strictly erect and scabrous, the pedicels
subsessile and scaberulous; spikelets greenish-white, glumes hyaline,
1-nerved, hispid on the keels, the lower broadest, about 7 mm. long,
gradually narrowed into a fine scabrous short awn, the upper one
narrower, 6 mm. long, bifid at the apex with a short awn or mucro
from the sinus; lemma minutely punctulate, distinctly scabrous above,
gradually passing into the strongly twisted column, inclusive of the sub-
acute, densely hairy, about 3/4 mm. long callus and the somewhat
scabrous column up to 6 mm. long, mostly shorter and always shorter
than the glumes; awns minutely scabrous, more or less spreading,
about equal, 10 mm. long. South America: Galapagos Islands. . . .
...............Aristida divulsa Andersson

14.nbsp;Upper glume acute, acuminate or shortly awned, not bifid at the apex. . 15.

contracted panicle and densely llowered spike-like panicle-branches.
Culms terete or slightly compressed, erect, 3—4-noded, branched from
most of the lower nodes, culm-nodes slightly swollen and protruding
above the dark-coloured sheath-nodes, internodes glabrous, striate,
smooth, dark-green or somewhat purplish; sheaths much shorter than
the internodes, slipping from the stems, subcompressed, stiiate, glabrous,
ligule a short ciliolate rim, auricles long-bearded, the hairs often
rufous and reflexed; blades linear, flat in lower part, convolute upwards,
glaucous-green, 25—30 cm. long or longer, 2—2\'/2 mm. wide at the
base, narrowed into a long setaceous point, glabrous beneath, slightly
scaberulous on the upper surface ami with some long hairs especially
at the mouth and near the base, the margins not conspicuously thickened,
scabrous, innovations much shorter and convolute throughout; panicle
up to 20 cm. long, contracted and more or less spike-like but some-
what loose, the axis visible, erect, interrupted at the base, rhachis
terete, glabrous and smooth below, subcompressed and scaberulous
above, branches erect, densely many-llowered, solitary, divided nearly
from the base, the branchlets fascicled, the lower including the spikelets
and awns 6—7 cm. long, the longer ones in each fascicle more or less
peduncled, with shorter branchlets at the base, scaberulous, longer
than the internodes of the rhachis, spikelets densely congested along

the branchlets, forming compact false spikes, pedicels very short;
spikelets yellowish-brown to pale-purplish, erect, linear-lanceolate,
glabrous, glumes I-nerved, cuspidate-awned, lower scabrous on the keel,
9—10 mm. long, upper one with a smooth keel, 11 mm. long; lemma
pimctulate or slightly scaberulous under a lens, the callus subacute,
up to 1 mm. long, densely long-hairy, including the scabrous, distinctly
twisted, about 4 mm. long column, up to 9 mm. long, the nodule at
the summit of the column very distinct, the awns breaking oflquot; at
maturity; awns scabrous, erectly spreading or divergent, about 20 mm.
long, or the lateral ones slightly shortei\'. South America: Brazil. . .
................Aristida Doelliaiia Heur.

Slender and delicate, up to 50 cm. high annual, mostly lower, with a thin
very loose, lax, rather few-ilowered panicle, ilowering the first year
and with a very faint root-system without innovations or sometimes
caespitose with sterile innovations and more robust, apparently perennial,
(such specimens belong probably to the hybrid between Aristida Doelliana
and A. setifolia and are placed under tbe var. arenaria of A. sdifolia.)
Compare that variety.

Culms very thin, 2 -3-noded, more or less branched from tbe lower
nodes, erect, striate, glabrous throughout; sheaths striate, glabrous,
shorter than the internodes, more or less slipping from the stems,
ligule a long-ciliate rim, auricles ciliate and bearded with long hairs,
collar glabrous; blades very thin and narrow, convolute-setaceous
throughout, striate, glabrous with scabrous margins, bearing some
scattered long hairs on the upper surface, 5 cm. long or less, sometimes
up to iO cm. long in robust specimens, scarcely 1 mm. wide when
ex[)anded; panicle exsei\'ted, very loose but more or less contracted,
linear to lanceolate-ovate, subsecund, erect or sometimes nodding at
the summit, branches distant, binate, naked in lower half part, spreadin«»\'
or more or le.ss ascending, often secund, scaberulous, the I\'hachis of the
panicle scabrous, angulous or subterete, the longer branches 4—8 cm.
long, sparingly branched above with few erect and adpressed spikelets
at the summit, the shorter branches with 2 spikelets or sometimes
with but one long-pedicelled spikelet, pedicels as long as or longer than
the glumes or those of the lateral llowers much shorter; spikelets
yellowish or straw-coloured, glumes linear-subulate or lanceolate
mucronate or shortly awned, glabrous, very variable in length, the
lower 0—12 mm. long, l-nerved or with I or 2 short additional side-
nerves, ciliate-scabrous on the keel, the upper one nearly glabrous on
tlie keel, I-nerved, 71/2—15 mm. long; lemma smooth, scaberulous at
tbe summit, including the callus and the scabrous,more or less twisted

column, very variable in length, 5—11 mm., sometimes up to 15 mm.
long or even slightly longer, the column exserted above the glumes
or not, awns scabrous, somewhat curved and spreading, subequal or
the central one somewhat longer, rather variable in length, mostly
12—20 mm. long or sometimes up to 30 mm. long. South America:

{Observation. This species is very variable as to the dimensions of
the spikelets, but nearly all the varieties agree in the vegetative
characters and are distinctly annual, only one variety is perennial,
and belongs to the hybrid between A. setifolia and A. Doelliana;
it is placed for the moment under A. setifolia because it was
described as var. arenaria of A. setifolia and placed there, till
the question is settled definitively.)

Delicate, slender, annual plants without innovations, panicles very
loose, the branches naked at the base over a long distance,
rather few-llowered, not forming dense false spikes.

Column of awns very short, about 1^2 mm. long, scarcely
or but very slightly twisted, lower glume 8 -10 mm. long,
upper one 10—11 mm. long, lemma inclusive ofthe callus and
column VVij—8 mm. long, awns curved and reflexed, up

Spikelets small, lower glume about 6 mm. long, upper
one about 7—8 mm. long, lemma inclusive of the callus
and column 5—G mm. long, awns 12—15 mm. long.
............ var. genuina Hour.

Spikelets large, broader than in the var. genuina, lower
glume 10—11 mm. long, the upper one up to 15 mm.
long, sometimes the glumes still longer and the lower
up to 15 mm., the upper sometimes up to 20 mm. long,
lemma inclusive ofthe callus and column 15—n^/a mm.
long, the column mostly exserted above the glumes,

More robust, perennial plants with numerous short innovations
which are intravaginal and dense, branches of the panicle
more or less sessile or naked at the base only over a short
distance, rather densely flowered and forming more or less
, distinct false spikes; spikelets rather small, lower glume 7—8
mm. long, upper one about 10 mm. long, lemma inclusive of the
callus and distinctly twisted column, 10-11 mm. long, the
column about 4 mm. long, awns subequal and up to 20 mm.
long. Hybrid between Aristida setifolia and A Doelliana. . .
............var. arenaria Trin. et Rupr.

16.nbsp;Perennial, densely caespitose plants, with many short innovations. . . .17.

upper glume about 8 mm. long, deeply bifid at the apex with a 1 mm.
long awn from the sinus and well-developed, acute, lateral setae;
lemma with callus and column about 6V2 mm. long; awns 11—12 mm. long.
Densely caespitose light-green or glaucous perennial with many short
imiovations, culms erect or geniculately ascending, slender, i-ather wii-y,
distinctly compressed, especially below and grooved laterally, slightly
scabrous or glabrous, simple or branched from the lower nodes,
3_4_noded, the glabrous culm-nodes slightly swollen and protruding
above the sheath-nodes; sheaths compressed or keeled, distinctly sca-
berulous, tight or more or less slipping from the stems where the
culms are branched, shorter than the internodes, mostly half as long,
ligule a densely ciliolate rim, auricles densely bearded with long erect
or spreading white hairs, the collar laterally bearded but glabrous on
the back; blades narrow, lineai-, not acuminate, acutish, the tip rather
obtuse and not setaceously pointed, u|) to 10 cm. long or somewhat
longer, the lower ones mostly much shorter and 2—3 cm long, cana-
liculate-folded or convolute, lather rigid, more or less curved, many-
nerved, with 5 more prominent white nerves and somewhat thickened
margins, glabrous and smooth beneath, scabrous and hispidulous on
the upper surface; panicle composed of more or less peduncled, often
nodding false spikes, ovate to oblong, mostly 10 cm. or sometimes up
to 15 cm. long, in other specimens rather narrow and only 5 cm. long
and at the same time with much shorter and shorter peduncled,
more erect, false spikes, axis straight or Ilexuous, subterete, striate and
scaberulous, branches solitary or binate, distant, filiform, spreading or
suberect, Ilexuous or straight, scaberulous, naked at the base over a
length of 3—4 cm., dense and spike-like at the summit, the scabrous

branchlets congested, erect and adpressed with scabrous short pedicels,
sometimes the branches very shortly peduncled and naked at the base
only for V2 cm.; spikelets brownish to purplish, glumes keeled, glabrous,
l-nerved, the lower lanceolate with a scabrous or scaberulous keel,
the upper one linear, smooth on the keel; lemma hnear-lanceolate
with a densely hairy subacute about 1 mm. long callus, the body
mottled, glabrous and punctulate below, very scabrous in upper half
part with white, hyaline, short tubercles at maturity, the lemma
including the callus about 41/2 mm. long, gradually passing into the
about 21/0 mm. long, strongly twisted column, awns scaberulous, fine,
about equal, more or less spreading. South .Africa: From the Coast

Plants less densely caespitose, shorter than the type, 15-20 cm.
high, nearly simple, mouth of the sheaths and auricles very
prominently bearded, the beards uniting into a ring at the
junction of the blade and the sheath, the hairs more spreading;
panicles strictly erect, slightly interrupted only at the base,
shorter, 5—6 cm. long, more dense and spike-like, the branches
solitary, 1—3 cm. long, strictly erect and adpressed, shorter
peduncled or sometimes nearly sessile, forming a spiciform
inflorescence, which is sometimes about 2 cm. broad. South

Lower glume 5 mm. long, long-awned, the awn at least 2 mm. long, upper
glume about 672 mm. long, slightly bifid at the ape.K with a 3/4 mm.
long awn from the sinus, the lateral lobes very short, sometimes
scarcely developed; lemma with callus and column about 8 mm. long;
awns 25—27 mm. long, the central one mostly longer and up to
30 cm. long.

Elegant, many-noded, up to 80 cm. high perennial, scantily branched
from some of the middle nodes, internodes nearly equal, 7—9 cm.
long, glabrous, smooth, striate, terete or slightly compressed, uppermost
internode very long and long-exserted, culm-nodes swollen and
protruding above the glabrous sheath-nodes; sheaths striate, smooth,
shorter than the internodes, slipping from the stems and rolled in at
their summit, or tight, rather broad and keeled at the base with
hyaline margins, upper sheaths slightly scaberulous, ligule a densely
ciliate short rim passing into tufts of hairs at the mouth, the auricles
and collar; blades up to 15 cm long, flat at the very base or mostly

narrowly convolute or plicate, keeled, striate, glabrous beneatb or
slightly scabrous only on tbe nerves, densely shortly pubescent on the
upper surface especially near the base, acute or acuminate and ending
in a fme subpungent tip; panicle very loose, up to 15 cm. long and
nearly 10 cm. broad with solitary branches, lower branches bifurcate
about! I mm. above their base, the upper ones undivided, all the
branches naked at their base for 2-4 cm., bearing at the summit
loosely contracted 3-5 cm. long, false spikes, rhachis straight
or somewhat curved, scabrous with many to numerous divaricate,
sometimes suberect or llexuous, not rarely drooping branches, branches
and branchlets very scabrous, axils shortly pubescent; spikelets densely
congested with very scabrous pedicels, the latter shorter than the
frlumes; spikelets purplish, glumes 1-nerved, scabrous or smooth,
narrowly linear, the lower but slightly scabrous on the keel, tbe upper
one smooth; lemma glabrous and smooth at the base or punctulate

acute callus, up to 5 mm. long, gradually narrowed into an elegant
densely twisted, about 3 mm. long column; awns very line, s[n-eading,
scaberulous. East Africa: Kilimandjaro and Tanganika Territorium to

Ramifications of the culms numerous, densely fascicled from the nodes,
very dilferent in form, those from the lower nodes abbreviate, iterately
fasciculately branched, those from the upper nodes of two kinds, lower
branches elongate, simple, 2—3-noded, sheathed, with a well-developed
tenninal panicle, upper branches reiterately fasciculately divided;
])anicles of the short branches linear, cotisisting only of 1—3 shortly
pedicelled adpressed spikelets, terminal panicles with 4—7 solitary
filiform branches, naked at the base for 2-3 cm., bearing at tbe
summit 12—25 mm. long and 3—5 mm. broad spiciform fascicles of
adpressed spikelets.

Pale \'n-een to yellowish plant with elegant culms, branched from the
middle and upper nodes, internodes glabrous, smooth; lower sheaths
broad, short, striate, glabrous, upper ones tight, striate, ligule a ciliate
rim auricles bearded, the collar smooth; blades setaceous, curved,
striate quot;labrous and smooth beneath, hirtellous on the upper surface,
very short, scarcely 2 cm. long, mostly sliorter; spikelets adpressed,
on erect, triquetrous, scabrous, subclavate pedicels, glumes linear,
narrow, very acute, shortly awned with denticulate-ciliate scabrous

keels, subequal, 1-nerved, up to 7 mm. long or the lower a little
shorter, I\'/s—2 mm. broad at the base; the lower commonly
scabrous also on the back, the upper one mostly quite smooth, bifid
at the apex with a short awn from the sinus; lemma narrowly linear,
inlcusive of the subobtuse, 1/2 mm. long, shortly pilose callus and the
twisted, scabrous about 2 mm. long column, up to 7V2 mm long,
minutely granular all over; awns very fine, nearly subequal, about

19. Panicles lax and very effuse, up to 15 cm. long, the branches suberect,
soon becoming widely spreading or divaricate, naked from the base
to the middle, densely floriferous at the summit.........20.

Panicles rather dense and congested, 5—7 cm. long or rarely longer,
branches about 2 cm. long, erect or but slightly spreading, densely
floriferous nearly to the very base.

Caespitose annual, forming small compact tufts, culms fascicled, ei\'ect
or geniculately ascending, inclusive ofthe panicles up to 10 cm. long
or sometimes up to 15 cm. long, very rarely in robust specimens up
to 25 cm. long, sheathed all along, branched and bearing inflorescenses
from some or most of the nodes, culms elegant, terete, striate, slightly
scaberulous; sheaths shorter than the internodes, prominently striate,
slightly scaberulous with hyaline margins, ligule a line of short hairs,
auricles long-bearded with white hairs, the collar glabrous; blades
narrowly linear, somewhat rigid, spreading, convolute, striate, glabrous
beneath or scabrous towards the apex, scabrous-hirtellous on the upper
surface, about 4 cm. long, .scarcely 1 mm. wide, finely acute,
subpungent; panicles linear to oblong, more or less fle.vuous, exserted,
5—8 cm. long, 1—2 cm wide, axis subterete, striate, glabrous or
scabrous above, branches solitary or sometimes binate, flexuous but
erect and adpressed, rather short, 2—3 cm. long without the awns,
floriferous nearly to the base or shortly peduncled, the peduncles very
thin, scaberulous and 5—8 mm. long, branchlets and pedicels minutely
scabrous, very short or the spikelets mostly subsessile; glumes pale
or straw-coloured, lanceolate, cuspidate, 1-nerved, very unequal, the
lower 5 mm, long, acute or shortly awned, scabrous on the keel, the
upper one 7—8 mm. long, smooth on the keel, shortly awned or
mucronate from a bifid apex; lemma linear-lanceolate or lanceolate-
oblong, minutely punctulate all over, with a long and densely bearded,
subacute, about 1 mm. long callus, the body of the lemma gradually
passing into a very scabrous, strongly twisted, 2—3 mm. long column,
totol length of lemma, callus and coiumn about 7 mm.; awns very

fine, scabrous, more or less spreading, slightly unequal, the central one
somewhat longer, up to 25 mm. long. Africa: Eastern Egypt to Sinai and
Western Arabia, also on the Cape Verd Islands, there probably introduced.
................Aristida iiieccana Höchst.

20. Column very long, mostly 2- 3-times as long as the body of the lemma.
Caespitose erect annual, culms elegant, erect, simple or sometimes
slightly branched from some of the middle nodes, up to 40 cm. high
or longer, thin, terete, striate, minutely scabrous, 2-3-noded, the
nodes placed in the lower half pai\'t of the culms, te nodes glabrous,
those of the culms slightly swollen and protruding above the sheath-
nodes; sheaths of the lower leaves shoi-t, more or less keeled, striate,
glabrous, those of the culm-leaves tight, distinctly scaberulous especially
above, shorter than the internodes, ligule a rim of short hairs, auricles
densely bearded, the collar laterally bearded with long, spreading
white hairs, the back of the collar glabrous; blades up to 10 cm. long
or those of the lower leaves shorter, sometimes flat at the base, mostly
convolute or folded, veiy narrow, scarcely 1 mm. wide when expanded,
gradually narrowed into a scabrous point, glabrous or minutely
scaberulous beneath, hirtellous or pubescent on the upper surface,
mostly somewhat curved or flexuous; panicles mostly long-exserted,
up to 15 cm. long, 5—6 cm. wide, very elegant, axis thin, subterete,
striate, scaberulous above, branches distant, binate, with thickened axils,
ascetiding or more or less spreading, about 5—ö cm. long without the
awns, iterately branched, the branchlets and pedicels rather short,
branches naked at the base over a long distance, bearing at the summit
0—8 or sometimes but 3-4 congested llowers, pedicels about as lon^
as the glumes or those of the lateral spikelets about half as long as the
glumes, scabrous and subclavate at the summit; glumes yellowish,
very unequal, 1-nerved, the lower one lanceolate and rather broad,
glabrous, very scabious on the keel, 3\'/2 mm. long, rather abruptly
narrowed into a very scabrous, IV2 mm. long awn, upper glume
narrower, quite smooth, about 8 mm. long, bifid at the summit with
an awn from the sinus; lemma rather thick, lanceolate-ovate with a
very acute, densely hairy about 3/4 mm. long callus, up to 3 mm.
long, glabrous and smooth below, very distinctly scabrous in upper
1/4 part, i-ather suddenly passing into the more than 7 mm. long,
scabrous, twisted column, rarely the column slightly shorter aiul
sometimes up to 10 mm. long; awns very fine, more or less spreading,
scabrous, nearly equal, about 25 mm. long. North East Africa:

Column much shorter or as long as the body of the lemma, sometimes
slightly longer and up to IV2 times its length.

Glaucous mostly 30—40 cm. high annual, sometimes up to 60 cm. high,
agreeing in habit and vegetative characters v^\'ith A. Cassanellii, culms
erect or geniculately ascending, more or less branched, subterete or
more or less compressed and grooved laterally, striate, slightly scabrous;
sheaths shorter than the internodes, compressed-keeled, sti\'iate and
scaberulous, ligule a ciliate rim, auricles with a tuft of hairs, collar
bearded laterally; blades not rarely Hat in lower half part, convolute
above or all over, linear, subacute, up to 10 cm. long, more or less
spreading, rather rigid, glabrous below, scabrous-hirtellous on the
upper surface; panicles long-exserted with solitary branches, the latter
5 — 7 cm. long, the spikelets at the summit densely congested, forming
curved, often nodding, false spikes; spikelets rather variable as to the
dimensions of the diilerent parts, the glumes ahvays unequal, sometimes
very prominently so, 1-nerved, the lower scabrous all over, asperulous
by short hairs, which are sometimes wanting, the body 5—6 mm. long,
gradually narrowed into an awn, sometimes the lower glume smooth
with a scabrous keel only, upper glume glabrous throughout, slightly
bifid at the apex with a mucro or short awn from the sinus, 673—7^2 mm.
long; lemma inclusive of the 3/4—1 mm. long, densely hairy, conical,
subacute callus and the laxly twisted, scabrous column, up to 7 mm.
long or sometimes up to 10 mm. long, the body of the lemma some-
times very scabrous at the summit; awns very fine, laxly spreading,
subequal or unequal, the central one mostly about 272 mm. longer
than the lateral ones. North Africa: From Senegal to Nubia, Abyssinia,

Glumes somewhat unequal, the lower one however never half as
long as the upper.
Glumes glabrous, with exception of the keel of the lower one.
Column of awns longer than the lemma, up to l^/j times
as long as the body, glumes and lemma as in var.

Column of awns shorter than the body of the lemma,
only 172 mm. long, distinctly twisted, the lower glume
with the 172 mm. long awn about 6 mm, long, the

upper one with the 1 mm. long awn about 8 mm, long,
lemma with column 51/2 mm, long, awns somewhat

Glumes at least the lower one scabrous nearly all over, the
upper one commonly glabrous, column as long as or shorter
Iban the body of the lemma.

Blades mostly convolute, lower glume 5 mm. long,
inclusive of the scarcely 1 mm. long awn, uppei-
one 6V2 mm, long, lemma with callus and column
up to 7 mm, long, lateral awns about 15 mm, long,

Blades mostly llat in the lower half part, lower glume
(i mm. long, upper one 7—8 mm. long, lemma
inclusive of the callus and column S^j^—d mm, long,
lateral awns about 22^2 mrn,, central one 25 mm.

Culms simple or nearly so, thin and elegant, blades elongate,
up to 15 cm. long, lower glume scabrous, otherwise as
in var. longiflora, but the panicle-branches commonly

Glumes very unequal, the upper twice as long as the lower one,
both glabrous, the keel of the lower glume scabrous, column
of awns about as long as the body of the lemma. Algerian


\'■■Ï-Â\';		■ ■ ■


	■ -

■ ■

■ii

In the year 1915, Domin proposed for a group of three Australian species, the
name of Arthrochaetaria with the diagnosis: „Ut Chaetaria sed aristae a glumella
conspicue articulataequot;. If we study these three species of Domin, we find however
that an articulation between the lemma and the awns is not present at all, there
is no special tissue and at maturity the awns do not break off. The three species
accepted by Domin as belonging to a distinct section, are indeed true Ghaetarias
and the name Arthrochaetaria is thus a synonym of Chaetaria. I have therefore
taken up the name Pseudochaetaria for a group of three African Aristidas, where
there is a true articulation between the body of the lemma and the awns, these
species have no column. The type of this section is Aristkla hordeacea, described
by Kunïii in the year 1830 as having an „arista tripartita articulataquot;. In the
year 1842, Trinius and Ruprecfit described Aristida Steudeliana and Aristida Kunthiana
and although they had seen the articulation, — they give „flosculo cum basi aristae
facile solubilis articulatim conjunctoquot; —, they placed these two species in their
first section „aristae persistentes setis nudisquot;, this proves that they have not given
much importance to the absence or presence of an articulation in our genus. The
section Pseudochaetaria is entirely limited to .\'\\frica.

Panicles densely contracted, compact and spike-like or interiu[)ted only
below, the bi-anches and pedicels always very short and the spikelets
fascicled; glumes manifestly long-awned.

Annual, erect or ascending, much branched from the base and some
of the lower nodes or simjile in meagre specimens, up to 40 cm. high,
or in small forms only 10 cm. high or shorter, robust forms commonly
much longer; culms strict, few-noded, the internodes densely pubescent

with reflexed orspreading, stiff, short hairs, striate, compressed 01\'subterete

in depauperate specimens, sometimes becoming nearly glabrous, nodes
constricted and densely pubescent or becoming more or less glabrous;
sheaths striate, keeled, pubescent, with narrow hyaline margins, shorter
or sometimes as long as the internodes, meagre specimens have more
terete, scabrous internodes only, ligules and auricles a shortly bearded
rim, collar smooth ; blades more or less glaucous, mostly flat or implicate
and keeled or in depauperate specimens somewhat convolute, narrow,
linear or commonly broad and Hat, acute, up to 10 cm. long or in
robust forms much longer and broader, scabi \'OUS on both surfaces oi\'
hirtellous above and becoming glabrous beneath; panicle linear-oblou\'^

or subovate, exserted, the peduncle densely pubescent, the inflorescense
commonly 6—7 cm. long and 1—3 cm. wide, in small forms much
shorter and only a few cm. long and nearly as broad, or in robust
forms much longer, axis densely pubescent, branches solitary, much
divided from the base, the branchlets and flowers fascicled, the short
pedicels pubescent; the panicle dense, not or slightly interrupted at
the base only, in robust forms more interrupted and the axis visible
in the lower part; spikelets congested, linear-lanceolate, glumes 1-nerved,
the lower 4 mm. long, rather broad, scabrous on the keel and on the
back, bifid at the apex with a scabrous, about 3 mm. long awn from
the sinus, upper one smooth on the keel or scaberulous on the back,
more deeply bifid at the apex, 5—6 mm. long, the awn about 2 mm.
long; lemma narrowly linear, fusiform, the acute, densely hairy callus
about 1/2 mm. long, the body scabrous witli very characteristic spiny
hairs in lines from the base to the summit, ventral side furrowed, but
the margins not quite inrolled, 5—6 mm. long, slightly narrowed but
scarcely beaked, the place of the articulation well-marked, awns about
equal, scabrous, strictly erect, about 15-20 mm. long or in robust
specimens much longer. Africa: Widely distributed from Senegambia
and the Sahara to Abyssinia, south to South West Africa and

Culms very robust, up to 1 meter high, blades up to 0 mm.
wide, quite Hat and many-nerved, panicles much longer
with the awns more than 20 cm. long and about 5 cm.
wide, much interrupted at the base, spikelets longer, the
lemmas up to 9 mm. long and the awns 6—7 cm. long.

Panicle contracted but no very dense, the branches erect or ascending,
s[)ikelets bearing nearly from the base; blades flat, lemmas shorter
than the unequal glumes which are obtuse and awn-pointed. JMant
with the habit of Aristida adscensionis.

Annual, much branched from the base, often forming hemispheric
tufts as much as 10 cm. in diameter, 10—40 cm. high, including the
panicles, culms erect or geniculately ascending, fasciculate, branched
from nearly all tlie nodes, terete, striate, scaberulous; sneaths about
as long as the internodes or longer, striate, keeled, glabrous, slipping
from the stems, ligules and auricles a minute ciliolate rim, collar

o-labroiis and smooth; blades narrow, hnear. Hat, the tips only seta-
ceously convolute and pointed, up to 2 mm. or sometimes only 1/2 mm.
^vifle, 8—iOcm. long, rather soft, not rigid, many-nerved, the margins
not thickened, glabrous beneath, scabrous or hirtellous on the upper
surface; nearly all the branches of the culms panicle-bearing, the
panicles erect, strict, contracted but not dense and spike-like, up to
10 cm, long and about 1 cm. wide without the awns, axis striate,
ano-ulous, scaberulous, branches scabrous, binate, the longer ones shortly
peduncled, the peduncle about i cm. long, the branches only a few cm,
long, many-flowered, the shorter ones sessile, spikelet-bearing from
the base, few-llowered, pedicels scabrous, shorter than the glumes, the
lateral flowers subsessile; spikelets yellowish-green, sometimes tinged
with pui\'ple, glumes about equal or the lower slightly shorter than
the upper one, 6—7 mm. or sometimes up to 8 mm..long, linear-
lanceolate, 1-nerved, the lower scabrous on the keel, acute, shortly
awned, the apex slightly bifid, upper one bifid, with obtuse lobes and
a mucro from the sinus, smooth on the keel; lemma compressed and
keeled, very scabrous nearly all over, the keel more or less spiny,
about 5 mm. long, the very short callus obtuse and densely hairy and
lono--bearded, the place of the articulation well-marked; awns rather
variable in length, slightly unequal or equal, scabrous, erect or somewhat
spreading, the central one about\'15 mm., the lateral ones up to 10 mm.
long or in robust specimens all the awns up to 25 mm. long. Africa:

\\uiicle very elTuse, the branches divaricately spreading, naked at the base
over a long distance; blades convolute or Hat only at the base; lemmas
about as long as the glumes, the latter very acute and manifestly
awned. Plant with the habit of Aristida nmtabilis.
Annual, culms erect, glabrous, up to 30 cm, high or much longer, thin
and elegant, filiform, sim[)le or branched from the middle nodes; sheaths
glabrous, striate, tight, shorter than the internodes, ligule a short ciliate
rim, auricles bearded; blades narrow, involute or convolute upwards,
Hat only at the base, the lower up to 5 cm, long or shorter, the culm-
blades up to 20 cm, long, ending in a setaceous point; panicle rather
depauperate, up to 15 cm. long, exserted, very eHuse, branches solitary,
alternate, elongate, nearly simple, spikelets bearing at the ends, tlu^
spikelets congested and forming false spikes, lower branches up to
10 cm. long, the upper ones gradually shorter; glumes about equal,
5_S mm., mostly about 7 mm. long, l-nerved, the lower linear-
lanceolate. gradually narrowed into the nearly 2 mm. long, scabrous

awn, the keel scabrous, the upper one but slightly longer than the
lower, smooth on the keel, manifestly bifid at the apex, the lobes acute
and very prominent, with a scabrous 1—1V2 mm. long awn from the
sinus; lemma with an acute about mm. long, densely hairy callus,
tubulous, more or less scabrous, but slightly narrowed and not beaked!
about as long as the glumes, the place of the articulation well-marked^
at maturity the awns easy to break off, scabrous, equal or slightly

Robert Brown described the genus Streptachne in the year 1810 and mentioned
as the most important character that the terminal awn is not articulated with the
valve. His specimens had no trace of latei-al awns and there was thus no reason
for him to bring his plants in connection with the genus ^nsiicZa. In the year 1799
Cavanflles had described a species as Aristida ternipes and here there are short
lateral awns, in the type of Cavanilles they ai-e scarcely 1 mm. long and in other
specimens of A. ternipes the lateral awns are nearly wanting. Five years after the
publication of the genus Streptachne, the authors of the Nova Genera et Species
IMantarum used the name Streptachne for a group of 3 American species. One of
them Streptachne scabra H. B. K. is the same species as Aristida ternipes Gawnilles,
ttie S. tenuis H. B. K. is only an immature A. ternipes, the Streptachne pilosa which\'
is Aristida jorullensis Kunth, is a very distinct annual species. If we compare these
species with the genus, described by Brown, it is impossible to find differences
in the spikelet-characters and we can find transitions between plants with short
lateral awns and others where the lateral awns are quite obsolete and absent. If
the central awn is the only developed one, we can find at the summit of the
column, the place of insertion of the lateral awns as a well-marked spot.

Trinius and Rupreciit accepted in the year 1842 Streptachne as a genus, they
added two other species, without having seen the type of R. Brown. These two
species Streptachne ramosissima and S. verticillata are indeed Stipeae, they belotiquot;
to the genus Stipa and the Russian authors overlooked the articulation. In the
Revision of the Australian species of Stipa by D. K. Hughes in the Kew Bulletin
(1921) no. 1 , these two species are placed under the doubtful ones. They belong
according to Miss Hughes to the genus Dichelachne, having 2, not 3 lodicules^
I have studied these two species and my conclusion is, that they belong to the
genus Sti])a; they have an articulation at the summit of the valve, but on account
of the coronula at the base of the awn this articulation is not so distinct as in
other species of the genus Stipa, if we have quite mature spikelets we find that
an articulation is present.

If we will take up Streptachne as a genus we must give generic rank to the différent

Other sections of the genus ^ris^/da, wiiich have better characters to distinguish them.

Aristida ramosissima, a species belonging to the section Chaetaria, is a good
example to demonstrate the reduction of the lateral awns, they are well-developed
in the var. Chaseana but commonly much shorter in the typical form, not rarely
the latei-al awns are obsolete or totally wanting in var. uniaristata, but we can find many
intermediary forms and it is impossible to separate this variety uniaristata as a species.

Prof. Hitchcock has in his work on the North American species of Aristida,
proposed the name Unisda for our section, he follows Mss. Hughes and accepts
Streptachne as a different and distinct genus.

The section Streptachne is among all the other groups of the genus Aristida the
less-characteristic one and scarcely to maintain and I have taken up this section
only for practical reasons; most of the typical members of this section are very
striking and easy to recognize.

If we place other species as Aristida utilis, A. ahnormis and A. redacta in this
section Streptachne, we must somewhat modify the characters of this grouj), because
these species have lateral awns sometimes as much as lt;3 mm. long, but these
latei\'al awns are merely bristles with a delicate texture, the central awn is a true
awn. In some cases the lemma is very curious, it consists of a lower tightly in j-olled
fertile part which encloses the grain as in other species of the germs. The upper
part of the lemma, the so-called sterile part, is much thinner and not tightly
inrolled but more or less gaping. At maturity the lemma breaks off sometimes
between the fertile and the sterile part as if there was an articulation. If we examine
however the place of the rupture, we find that an articulation is not present and
that the rupture is artificial. The section Streptachne is not a very natural one and
it is impossible to limit it sharply It is probably better to unite Streptachne and
Chaetaria, but for practical reasons I have separated them in this work.

The section as accepted here is rather heterogeneous and the distribution is also
cuiious. Three species are natives of Australia, one of them also found in British
New^ Guinea. One species occurs in British India and another in North East Africa,
the latter is also found in Persia. All these Old World species are more allied and
form a distinct group which agrees better with the old genus Streptachne. The 8
New World species, especially natives of Florida, Arizona, Mexico and the North
Western part of South America, are more allied to the section Chaetaria.

Internodes, at least the lower ones, densely villous or woolly-pubescent
with weak long hairs; sheaths sparingly hairy, the iiairs long and
flexuous.

culms slender, simple, terete, few-noded, the nodes congested in lower
part of the culm, lower internodes short, the uppermost one or peduncle
very long, glabrous or minutely pubescent, the lower internodes woolly
but the sheath-nodes nearly or quite glabrous; sheaths shorter than
the internodes, tight, terete, the uppermost one nearly glabrous, ligule
a short truncate ciliolate rim, auricles pubescent and more or less bearded
especially the innovations with long-bearded auricles, collar quite
smooth; blades narrow. Hat only at the base, convolute, setaceous,
somewhat rigid, curved, mostly 7—15 cm. long, acuminate, glabrous or
scaberulous on the upper surface only, scarcely 1 mm wide when
expanded; panicle slender, 25—35 cm. long, somewhat contracted but
rather loose, rhachis terete, scabrous, smooth below, the lower branches
distant, suberect or slightly spreading with capillary scabrous branchlets
and pedicels, branches binate or nearly solitary, the longer ones naked
at the base, the shorter ones subsessile, few-flowered, sometimes all
the branches- bearing but 1—2 spikelets; spikelets erect, the lateral
ones longer than the pedicels, glabrous or scaberulous, glumes lan-
ceolate, subequal, the lower mostly a little longer and prominently
3-nerved or sub-5-nerved, acute, awned, 9—11 mm. long, very scabrous
on the keel, the upper one narrower, hyaline, 1-nerved, 7—972 mm.
long, slightly bifid at the apex with an awn from the sinus; lemma
smooth or slightly scaberulous only upwards, punctulate, about 11 mm.
long, tubulous, the subacute densely hairy callus about mm long,
the body of the lemma gradually narrowed into a scabrous, twisted,
somewhat spreading, 5 mm. long column, central awn spreading, quite
straight, up to 10 mm. long, the lateral awns erect, shorter and much
thinner and finer, about 4 mm. long, all the awns scabrous. Australia:

Axis of panicle, branchlets and pedicels glabrous or scabrous only, always
without long hairs....................

Axis of panicle, branchlets and pedicels sparingly beset with long hairs.
Slender, tufted, mostly 20—40 cm. or sometimes up to 60 cm. high,
much branched annual, culms striate, glabrous or minutely scaberulous,
terete or subcompressed; sheaths glabrous, striate, slightly compressed
or subterete, much shorter than the internodes, ligule a ciliolate rim,
auricles pubescent or with a few deciduous hairs, collar smooth ; blades
narrow, 1—2 mm. wide, ilat, soon becoming involute, tapering to a
fine point, up to 10 cm. long, glabrous beneath, scabrous or hirtellous
on the upper surface, mostly with scattered long hairs near the base
and the mouth; panicles narrow, 10-20 cm long, with somewhat

flexuous axis and short distant branches, spikelets bearing from the
b\'ise-panicle and peduncle at maturity much elongated, axils of branches,
branchlets and pedicels with long hairs, angulous and scabrous;
SDikelets olabrous or pubescent, not rarely with long hairs at the tip,
of two kinds, the larger spikelets with very unequal glumes, lower
one 9 mm 1-nerved, or sub-3-nerved, acute or shortly awn-pointed,
with quot;very scabrous keel, broader than the up to 5 mm. long, 1-nerved
UDper one with a smootli keel, tip obtusely obliquely awn-pointed,
tlie smaller spikelets in the same panicle with nearly equal, sliorter
alumes\\ind the lemmas with shorter awns; lemmas very scabrous,
especially on the keel, gradually passing into a straight or somewhat
curved not twisted, scabrous somewhat compressed column, bearing
a scabrous terete awn, lateral awns wanting, tlie callus short, scarcely
1// mm long, sparingly long-pilose; lemma including callus, column
and awn very diilerent in length, 20-35 mm. long, in the smaller
spikelets up to 15 mm. long. Central America: Mexico to Panama. . . .
\'\'nbsp;.........Aristida jornlleiisis Kuiith

3 Body of the lemma consisting of a fertile lower part and a sterile mostly
\'broader and thinner upper part, gradually passing into a straight or
twisted column, which passes into the central awn, lateral awns nearly
totally wanting or well-developed, but always very thin; annual plants.

Body ofquot; the lemma gradually |)assing into a twisted or straight, sometimes
wantiuquot;\' column, no broad sterile part between the column and the
lemma ; perennial, rarely annual plants............

4 Fertile part of the lemma narrow, very scabrous and somewhat tuberculate
in the upper part, sterile part together with the column and awns
easily breaking off at maturity, but without an articulation, the rupture
caused by the great difl\'erence in texture between the indurate lower
and the papery or chartaceous sterile up[)er part of the lemma; mouth
of the sheaths and auricles shortly pilose.

Culms simple or sparingly branched, slightly compressed, striate, glabrous,
loosely sheathed, 30—00 cm. high; sheaths glabrous, striate, about as
long as the internodes or somewhat longer or shorter, ligule shortly
ciliate, collar glabrous; blades setaceous, convolute, the basal leaves
short, smooth loeneath, hirtellous on tlie upper surface, margins and
lower part of the blades sparingly hairy; panicle contracted but very
lax, sometimes broader and ovate in outline or nearly as long as broad
with geminate, distant, flexuous, spreading branches and branchlets,
pedicels unequal, shorter than the glumes, the branches naked at the
base and scaberulous; glumes subequal, narrowly lanceolate, subulate.

long, the lower awned, slightly scaberulous on the keel, the upper one
with a bifid apex and an awn from the sinus, lemma with a
narrow base, gradually enlarged, the sterile part smooth, including the
long-bearded acute callus, about 10 mm. long, the twisted cofumn
up to 13 mm. long; central awn divergent about 20 mm lone the
ateral awns wanting or very short, very thin, sometimes up toOmm.
long. British India............

Fertile part of the lemma slightly hairy only in the upper part, not tuber-
culate, sterile part not breaking olf at mat.irity, no rupture between
sterile and fertile part of the lemma; mouth of the sheaths and auricles
long-bearded.

Culms caespitose, branched from the lower and most of the upper
nodes, 15-40 cm. high, scaberulous or smooth, striate, terete or sub-
compressed; sheaths shorter than the internodes, glabrous, smooth
sulcate or striate, ligule a densely hairy rim, auricles prominently
bearded, collar smooth; blades setaceous, up to 10 cm. long, somewhat
rigidulous, very narrow, convolute, curved, striate, smooth, tips rough •
panicle ovate, very lax and open, 5-10 cm. long, with short, solitary
or geminate, erect or somewhat divergent branches, the latter naked
at the base, scaberulous only or nearly smooth, pedicels short nearly
smooth; spikelets somewhat clustered at the ends of the branchlets
pedicels shorter than the glumes, the latter subequal, 7—8 mm. long!

the upper slightly ciliate at the minutely bifid apex, with a mucro
from the sinus, the lower one acuminate, awn-pointed, the nerves
scaberulous; lemma 10 mm. long, 1-nerved, scabrous on the keel,
. shortly hairy at the summit and on the upper margins, abruptly
narrowed into a divergent, strongly twisted, 8 mm. long column, callus
acute, long-bearded, up to IV2 mm. long; central awn 15—17 mm.
long, lateral awns welJ-deveJoped but very thin, up to 7 mm. Ion«-.

lateral nerves short or obsolete, upper glume always 1-nerved
Lower glume 5-nerved, upper one 3-nerved. North American annual species,\'
much branched from the base and all tne nodes; central awn strongly
curved and rellexed, lateral awns sometimes obsolete or nearly wanthig
or well-developed. See under the section Ghaetaria. ...... \\

Prolongation of the lemma always straight, geniculate, forming an obtuse
anwle, the awns sometimes horizontally bowed, lateral ones developed

Column of awns well-developed, twisted all over, passing into the awn
without indication of lateral awns.

Panicle erect, the branches erect or ascending or slightly spreading,
the pedicels mostly longer or those of the lateral spikelets shorter than
the acute glumes, the latter awn-pointed, 11 - 13 mm. long, glabrous,
nearly equal or the lower one slightly longer than the upper, the lower
3-nerved the upper one 1-nerved; lemma terete, tubulous, narrowly
linear including the subobtuse, hairy about 1 mm. long callus, up to
14 mm. long, the strongly twisted straight column about 7 mm. long,
the awn slightly curved and up to 16 mm. long. Australia: N. E.
Queensland. Very imperfectly known species, described from the type
specimen, lacking the base and the leaves. It was hitherto only collected

8nbsp;I^anicle open, large and effuse, at first sometimes somewhat contracted but

I^anicle narrow, condensed, branches 3—5 cm. long, spikelets bearing nearly
to the base; column of awns somewhat twisted and slightly curved in
the lower part.

Caespitose pereimial, culms about 60 cm. high, simple, slender, erect,
sheaths bearded at the mouth; blades long, filiform, convolute, smooth ;
panicle half as long as the whole plant, erect, branches geminate,
distant, scabrous, spikelets on short scabrous pedicels; glumes linear,
1-nerved, nearly equal, 8—8\'/2 long, or the lower up to 10 mm.
long, the lower awn-pointed, hispidulous on the keel, the upper one
smooth, truncate, mucronately awned from a bifid apex; callus bearded
laterally, subobtuse, about 3/4 mm. long, lemma smooth, the body
about as long as the glumes or shorter, linear-subulate, convolute,
gradually passing into the long, laterally compressed, loosely curved
and twisted column, the length of the lemma including column and

awn, about 30-35 mm, lateral awns totally wanting or minute points
only. North America: Southern Florida, Key West. Only known from
the type specimen, collected by Blodgett.......

9. Column of awn well-developed as a laterally compressed, scabrous, somewhat
falcate not twisted beak.............

Column of awn wanting or scarcely developed but never compressed\' or
falcate. Lateral awns mostly well-developed and about 4—6 mm. long
or sometimes in immature plants only 1—2 mm. long, the central

10. Panicle erect, more than half the length of the whole plant, the branches
about 5 cm. long, usually stiffly spreading or refiexed, mostly bearing
one or several short branches at the base with a pair of spikeletsquot;
A rather small often prostrate or ascending plant, about 25 cm. highj
rather slender, sometimes branched from the lower nodes ; sheatlis
glabrous, or scabrous above, slightly hairy or glabrous near the mouth;
blades involute, 15—30 cm. long, very scabrous on both sui\'faces or
glabrous beneath,the auricles long-bearded but the collars smooth,
flat below, soon becoming involute, narrowly linear; panicles elfuse,\'
branches capillary, at first erectly spreading, single, distant, scabrous^
becoming divergent; lateral spikelets on very short scabrous pedicels,
terminal spikelet of each branchlet with a pedicel up to 10 mm. lono-\'
glumes about equal or slightly unequal, 9-13 mm., mostly about
11 mm. long, if unequal one of them V^—1 mm. longer or shorter than
the other, glabrous and smooth, or the lower minutely scaberulous,
both awn-pointed, the upper one somewhat laciniate-truncate at the
summit; lemmas including the shortly hairy subobtuse callus and the
awn, variable in length. 22—29 mm., but mostly 24—25 mm. Ionquot;\'
glabrous, somewhat scabrous on the keel above; central awn scabrous
lateral ones minute or sometimes slightly developed and 1—3 mm.
long. Southern United States: Texas and Arizona to Nicaragua.
.................Aristida divorgens Vasey

Panicle erect, nodding at the summit, 1/3—1/2 the entire length of the
culms, branches few, very long, spreading and flexuous, solitary or
fascicled, mostly naked at the base.

A rather large, erect perennial with erect firm glabrous culms, 50 cm.
or up to 1 meter high; sheaths glabrous or scabrous above, ligule

minutely pubescent, auricles bearded, the collar sometimes slightly
hairy; blades flat at the base, soon becoming involute, tapering into a
fine convolute point, narrow, 2—3 mm. wide, up to 40 cm. long,
glabrous beneath or scabrous on both surfaces, with long hairs near

the base; panicles open, the scabrous branches rather long, the spikelets
more or less adpressed at the end of the branches, pedicels short,
scabrous; glumes mostly unequal, 1-nerved, the lower acute, broader
than the upper one, up to 16 mm. long, awned, with very scabrous
keel or scaberulous all over, the upper but slightly scabrous on the
keel, smooth, truncate at the summit, shortly awned, up to 13 mm.
long; lemma glabrous often mottled with purple, the long-hairy,
subobtuse callus about 3/4 mm. long, the hairs exceeding the true base
of the lemma which is gradually narrowed into a somewhat laterally
compressed, very scabrous, nerved beak or column, extending into a
scabrous nearly terete, straight or arcuate central awn, the total
length of lemma and awn about 40 mm. long, but not rarely much
shorter and only about 25 mm. long, at the same time the glumes
much shorter and only 8—10 mm. long, lateral awns totally wanting
or scarcely 1 mm. long. Southern United States from Arizona and

11. Panicles rather robust, very loose and diffuse or somewhat contracted, if
rather narrow always with very long branches, naked at the base
ovei\' a long distance or with a shorter basal branch at the base. North
American species . . \'.............. , , . 12.

Panicles not robust, very narrow, contracted, somewhat interrupted, the
branches very short and adpressed.

Caespitose elegant perennial, sometimes llowering in the first year and
apparently annual, few-noded, culms strictly erect, about 20—35 cm.
high including the panicle, terete, smooth; sheaths shorter tlian the
internodes, tight, striate and glabrous, ligules and aui-icles shortly
ciliolate, collar smooth; blades very narrow, convolute setaceous,
somewhat glaucous, often curved, glabrous beneath, scabrous on the
upper surface and on the margins, ending in a long setaceous point,
up to 10 cm. long, scarcely 3/4 mm. wide when expaiuled; panicles
ratlier small, up to 15 cm. long, scarcely 1/2 cm. broad, linear,
interrupted, the axis totally visible, the branches short, few-llowered,
scaberulous, binate or subsolitary, the longer ones about 3 cm. long
with 1 or 2 sessile spikelets at the base or both branches but 1-flowered,
rhachis smooth, the branches and pedicels scaberulous; spikelets
yellowish, erect, mostly very shortly, or sometimes huiger pedicelled and

the pedicels 3-4 mm. long; glumes linear-lanceolate,smooth, 6—8 mm.
or not rarely up to 10 mm. long, equal, acuminate, the lower one
3-nerved or 5-nerved, slightly scabrous on the keel, the upper one
1-nerved, scabrous only at the tip; lemma narrowly linear, tubulous,
quite smooth, with a densely hairy about V2 mm. long, subacute callus,

long awn, the lateral awns very thin, up to 2 mm. long, rarely obsolete
and nearly wanting. Australia: Queensland. . .

13.nbsp;Glumes without inverse position, subequal or the lower one distinctly shorter

Glumes with inverse position, lower prominently longer than the upper one,
glumes quite glabrous, scabrous only on the keel of the lower one.
Caespitose perennial forming small tufts with rather short intravaginal
innovations, 60 cm. to more than 1 meter high; culms terete, slightly
pubescent or scaberulous, 3—5-noded, erect; sheaths longer than the
internodes, terete, striate, tight, pubescent or scaberulous, ligule a
minute ciliolate rim, auricles pubescent, those of the innovations bearded
collar smooth; culm-blades up to 20 cm. long, Hat or becomino- in-
volute, ending in a setaceous point, about 1 nun. wide, scaberulous
or smooth beneath, hirtellous on the upper surface, the old leaves
curved and flexuous, margins not conspicuously thickened; peduncle of
the inflorescence very long, exserted; panicle very open and dilfuse or
more or less contracted, axis terete, striate, scabrous, or angulous and
very rough upwards, the axils minutely ciliate or glabrous, branches binate
or solitary, naked at the base over a long distance, long and spreading, not
rarely the lower ones deflexed and drooping, spikelets adpressed and
congested at the end of the branchlets; branches, branchlets and
pedicels scabrous; in less-developed contracted panicles the branches
are much shorter, erect or ascending, often only a few cm. long and
few-flowered, bearing sometimes but 1 flower; spikelets yellowish or
brown, lower glume S\'/a—14 mm. long, sometimes still longer and up
to 16 mm. long, 1-nerved or not rarely with shorter lateral nerves and
prominently 3-nerved, scabrous on the keel, the upper one 7—10 mm.
long, in robust specimens not rarely up to 14 mm. long, smooth on
the keel, 1-nerved, both shortly mucronate from a more or less
distinct bifid apex, glabrous and smooth or minutely scaberulous only;

lemma punctulate, the subacute, densely liairy callus about 1 mm.
long, the body up to 10 mm. long, mostly purplish, the distinctly
twisted scabrous column about as long as the body of the lemma; awn
geniculate, 5—15 mm. long, scabrous, lateral ones minute. A species
of more northern range. North America: Arizona to northern Mexico, . .
............... Aristida Orcuttiana Vasey

\'14. Auricles densely pubescent and bearded, with a villous line across the
collar; lateral awns of the column slightly developed and up to

(Observation: Aristida Karwinskiana Trin. et Rupr. is not so
easily recognized. The specimens of the type are fragmentary
and immature. The short lateral awns indicate A. Schiedeana
but the villous line across the collar is a character of A. laxa.
It may be that this A. Karwinskiana is a liybrid between the
two species.)

Auricles shortly pubescent only, even those of the innovations not con-
spicuously bearded, no villous line across tbe collar, whicli is smooth
or minutely puberulous only.

Densely caespitose perennial, 40—90 cm. or more than 1 meter high,
agreeing in habit and vegetative characters with Aristida Orcuttiana.
They have not rarely the same aspect and intermediary ibrms occur
between tbem. There are moreover forms with more or less bearded
auricles and a prominent villous line across the collar, such specimens
are probably hybrids between A. laxa and A. Schiedeana.
Panicles exserted, culms erect, glabrous or somewhat scaberulous •
sheaths glabrous or minutely pubescent; blades llat and involute upwards,
glabrous beneath, scaberulous on the upper surface, as much as 3 mm.
wide, tapering to a line point; panicle long, open or somewhat contracted
with few, long, binate, scabrous brandies, naked below, ascending or
spreading and drooping, sometimes as much as 10 cm. long, branched
from the middle with adpressed branchlets and pedicels, the spikelets
more or less crowded at the ends of the branches, pedicels anoulous
and scabrous, the lateral ones shorter than the glumes and up to 3 mm,
long; glumes nearly equal, 9-10 mm. long, both or at least the lower
one distinctly pubescent and 1-nerved or with a pair of lateral nerves
scabrous on the keel, the upper one smooth on the keel, both awned
from a more or less bitid apex, the awn often more than 1 mm. lono -
lemma about 8 mm. long, including the column up to 15 mm. long

smooth, callus rather obtuse, densely bearded, the column scabrous
and strongly twisted, central awn up to 12 mm. long, lateral ones
about 1 mm. long or minute. A species of more southern range.
Southern Mexico to Guatamala and Ecuador..........

15. Lower glume shorter than the upper; sheaths glabrous, pilose at the throat;
lemma including the very short column about 10 mm. long, callus
long-hairy.

Caespitose perennial, culms erect, slender, rather rigid, glabrous,
50—60 cm. high; sheaths tight, blades 5-10 cm. long and 1—2 mm!
wide. Hat at the base, becoming involute; panicles open, narrowly
pyramidal, 15-25 cm. long, the branches few, few-flowered, stiffly
ascending finally spreading or reflexed, the lower ones 5-6 cm. long,
the branchlets and pedicels stiffly ascending; glumes 1-nerved, unequal\',
the lower about 6 mm. long, abruptly narrowed into the short awn,
scabrous on the keel, the upper one 8 mm. long, smooth on the keel^
notched or slightly bifid at the apex, scarcely mucronate; lemma
tubulous, glabrous and smooth, minutely scaberulous only on the keel
and on the very short beak, more or less mottled, the callus densely
and long-bearded, subacute and nearly 1 mm. long or slightly shorter;
central awn about 8 mm. long, straight, scabrous, recurved by a
semicircular bend, the lateral ones scarcely 1 mm. long. North America:
Lower California................

Lower glume longer than the upper one; sheaths scaberulous, not hairy
at the throat; lemma including the straight, up to 6 mm. long column,
about 14 mm. long, callus not so densely hairy.
Perennial, culms including the panicle at least 40—50 cm. high, erect,
terete, striate, scaberulous; sheaths striate, tight, terete, distinctly scabrous
in lines especially between the nerves, ligule a short ciliolate rim, auricles
pubescent, collar smooth; blades 25—30 cm. long, flat at the very base,
involute upward.?, scaberulous or densely hirtellous on both surfaces
or becoming glabrous beneath, strongly nerved but the margins not
conspicuously thickened, 1—2 mm. wide when expanded; panicle
strictly erect, 10—20 cm. long, loose but rather narrow, axis very
scabrous, terete and striate below, angulous upwards, branches solitary
stiffly ascending at an angle of about 45 degrees, distant, with a very
short 1-2-flowered branchlet at the base, the lower ones about 3 cm.
long, bearing 4-6 spikelets, the branches gradually becoming shorter,
the uppermost ones bearing but 1—2 spikelets, axils minutely pubescent,

branches and pedicels scabrous, the pedicels of the lateral spikelets
very short, the other ones half as long or sometimes nearly as
longas the glumes;, spikelets pale or brownish, glumes 1-nerved,
glabrous or slightly scaberulous only on the keel of the lower
one near the apex, the first 12 mm. long, gradually narrowed into
the about 2 mm. long scabrous awn, the upper one 10 mm. long,
rather abruptly narrowed into the 1 mm. long awn, or subbifid; body
of the lemma 8 mm. long, punctulate, gradually narrowed into the
scabrous up to 6 mm. long, slightly compressed column, callus obtuse,
about 3/4 mm. long; central awn about 8 mm. long, scabrous, straight,
geniculate, horizontal or refiexed, the lateral ones erect, minute, less

Vorm en ontwikkelingsgraad van den callus bij de kroonkafjes
der grassen zijn afhankelijk van de plaats die er voor dat orgaan is op
de bloeias.

Bij de beoordeeling der variabiliteit der pbanerogamen in \'t algemeen
en meer bijzonder bij de glumilloren, dient meer rekening gehouden te
worden met de florale syndimorphie en behooren een groot aantal van
de beschreven en benoemde varieteiten uit de florawerken te verdwijnen.

De door Prof. N. I. Vavilov opgestelde „Law of homologous series
in variationquot;, is voor de systematiek en de monographische behandeling
der soort van verstrekkende beteekenis.

De theorie van Wegener over de verschuiving der continenten
wordt niet gesteund door en is niet in overeenstemming met de geogra-
phische verbreiding van het ruim 320 soorten tellende, ovej- alle wereld-
deelen verbreide, geslacht Aristida.

De onzekerheid bij de determinatie van de tot de Gastropoda,,
onderorde Stylommatophora beboerende soorten uit de familie der barn-
steenslakken (Succinea) en de groote diversiteit in dit geslacht, berust
op bastaardeering.

Niettegenstaande dat de anatomie der recente Mollusca voor de
indeeling van groot malacologisch belang is, dient toch voor de syste-
matische behandeling dezer klasse een overwegend aandeel gegeven te
worden aan de conchiologische bewerking der soorten.

De door Valckenier Suringar voorgestelde benoeming van bastaarden
■door den naam der oudersoort, op welke de bastaard het meest lijkt,
te verbinden met den uitgang „oidesquot; of „oidensquot;, verdient geen navolging
en zal in de toekomst tot moeilijkbeden voeren.

De beide door Linnaeus beschreven geslachten Hydrocotyle en
Centella zijn systematisch twee goed gekarakteriseerde genera. De als
stamplant door de Pharmacop. genoemde Hydrocotyle asiatica L. be-
hoort tot het geslacht Centella en moet genoemd worden: Centella
asiatica (L.) Urban.

De stamplant der Fructus Bruceae der Ph. N. ed. V., opgegeven
als de door Roxburgh beschreven Brucea sumatrana is reeds veel eerder
door Loureiro onder het geslacht Gonus beschreven en behoort als
Brucea amarissima (Lour.) Desvaux te worden opgenomen.

Bij de beschrijving van de Flores Cinae in de Pharm. N. ed. V.,
had een quantitatieve bepahng opgenomen moeten worden, w^aarin als
eisch een minimum gehalte aan santonine had dienen te worden gesteld.

Voor het microchemisch aantoonen van santonine in het verkregen
sublimaat, biedt het gebruik van verdund zoutzuur geen voordeel aan

C. van Zijp; Microch. Budr. betreffondo santonine enz. Pliarm. Weekb. 64, 278.
F. Amelink; Sdioraa voor inicrocli. identif. van alcaloiden pag. 115.

Verschillende wijzigingen hi de namen der stamplanten van in de
Ned. Pharmac. opgenomen simplicia, behooren te worden onderworpen
aan het oordeel van de systematici.

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