The third glume is narrow, long, awn 3-fid 31. Aristida.

Sub. Tribe 2. =Euagrosteae=.--The spikelets are very small, in open or contracted panicles.

The third glume is thin and membranous, awnless. 32. Sporobolus.

=Chlorideae= is also a small tribe with about ten genera, most of them being very common in Southern India. The spikelets are unilaterally biseriate on the rachis which is not jointed at the base. There are one or more flowers in the spikelet, all or only the lowest being bis.e.xual.

The rachilla is jointed just above the empty glumes and it is produced or not beyond the flowering glumes. The inflorescence consists of spikes, or spiciform racemes, solitary or digitate, and in some it is paniculate.

Rachilla produced beyond the flowering glume.

Spikes usually solitary.

Spikelets 1- to 2-flowered, pedicelled and in deciduous cl.u.s.ters, awned. 33. Gracilea.

Spikelets 1- to 2-flowered, not cl.u.s.tered awned. 34. Enteropogon.

Spikes or spiciform racemes digitate or whorled.

Spikelets 1-flowered and with three glumes, awnless. 35. Cynodon.

Rachilla not produced beyond the flowering glumes.

Spikelets 2- or more-flowered, glumes five or more, awned, upper flowers imperfect. 36. Chloris.

Spikelets 3- to 6-flowered, densely crowded, awnless. 37. Eleusine.

Spikes or spiciform spikes racemed, spikelets 2- to 3-flowered, 4- to 5-glumed, awned. 38. Dinebra.

Spikes panicled, filiform, spikelets very minute one-or more-flowered, glumes awnless. 39. Leptochloa.

31. Aristida, _L._

These are tufted, annual or perennial gra.s.ses. Spikelets are panicled, 1-flowered, laterally compressed, with the rachilla jointed above the empty glumes, 3-glumed. The first and the second glumes are narrow, keeled, 1-nerved, awned or not and persistent. The third glume is very narrow, cylindric, coriaceous, convolute, ac.u.minate, 3-nerved, tip produced into a long 3-part.i.te, naked or hairy awn twisted below the branches, with a minute palea which is convolute round the ovary.

Lodicules are two, linear or oblong-linear and hyaline. Stamens are three. Styles are distinct. Grain is long, narrow and cylindrical.

KEY TO THE SPECIES.

Awn tripart.i.te from the base and not articulate with the top of the glume, persistent and glabrous.

Annual.

Glumes I and II not awned.

Awn without any column and branched from the base. 1. A. Adscenscionis.

Awn with a short column and with shorter branches. 4. A. mutabilis.

Perennial.

Panicle cylindric, glumes I and II awned; callus with white silky hairs. 2. A. setacea.

Panicle effuse, glumes I and II awned or not; callus naked. 3. A. Hystrix.

Awn with a long column, tripart.i.te at the top.

Annual; panicle lax, narrow; glumes I and II awned. 5. A. funiculata.

[Ill.u.s.tration: Fig. 171.--Aristida Adscenscionis.]

=Aristida Adscenscionis, _L._=

This gra.s.s is usually an annual becoming a perennial under favourable conditions. Stems are slender, sometimes even filiform, erect, or ascending, simple or branched, varying in length from 9 inches to 3 feet.

The _leaf-sheath_ is glabrous, thinly striate. The _ligule_ is a row of fine short hairs. _Nodes_ are glabrous.

The _leaf-blade_ is narrow, linear, tapering to a fine point, convolute in bud, scabrid above and smooth below, with a minutely serrate, very narrow, hyaline margin, 1 to 10 inches long and 1/12 inch broad.

The _inflorescence_ is a lax, narrow, subsecund panicle, varying in length from 3 to 12 inches, and with a slender glabrous peduncle; the main rachis is filiform and glabrous; branches are either solitary or binate, unequal; branched either from the middle or the base; _pedicels_ are short and capillary.

[Ill.u.s.tration: Fig. 172.--Aristida Adscenscionis.

1. A spikelet; 2. first and second glumes; 3. palea; 4. lodicules, stamens and ovary; 5. third glume with awns; 6. grain.]

The _spikelets_ are narrow, erect, green, occasionally also purplish, 1/4 to 1/3 inch long exclusive of the awn. There are three _glumes_. The _first glume_ is linear-lanceolate, acute, membranous, 1-nerved with a scaberulous keel, 1/16 to 3/16 inch long. The _second glume_ is longer than the first, linear-lanceolate, acute, occasionally 2-toothed and apiculate, 1-veined about 1/4 inch long and with a smooth keel. The _third glume_ is as long as the second or slightly longer, laterally compressed, 3-nerved, smooth but scaberulous along the keel, awned; there are three scabrid _awns_, varying in length from 1/2 to 3/4 inch, continuous with the glume without a column, not jointed, and the middle awn is longer than the lateral ones; the callus is long, pointed and villous. There is a minute _palea. Lodicules_ are two, similar to the palea in size, linear oblong. _Anthers_ are yellow dotted with purple.

The _ovary_ is oblong linear with two white feathery _stigmas_.

Grain is long and linear.

This when young is eaten by cattle, but they do not like it when in flower.

_Distribution._--Occurs all over the Presidency in the plains and the low hills.

=Aristida setacea, _Retz._=

This is a tall coa.r.s.e perennial gra.s.s with hard, smooth and polished, stout, erect simple or branched stems, 3 to 4 feet. Roots are stout and wiry.

The _leaf-sheath_ is glabrous, cylindrical. The _ligule_ is a row of short hairs. The _nodes_ are glabrous.

The _leaf-blade_ is linear, coriaceous, convolute, glabrous, strongly nerved, 6 to 12 inches long.

The _inflorescence_ is a contracted _panicle_ varying from 6 to 18 inches with short, erect or subsecund branches.

[Ill.u.s.tration: Fig. 173.--Aristida setacea.

1. The spikelet; 2 and 3. the first and the second glume; 4. the lower portion of the third glume, anther, ovary and the lodicules; 5. palea of the third glume.]