- Sub. Tribe 1. Stipeæ.—The spikelets are narrow and long,
panicles and the flowering glumes are rigid or hard, and awned.
- The third glume is narrow, long, awn 3-fid. 31. Aristida.
- Sub. Tribe 2. Euagrosteæ.—The spikelets are very small, in
open or contracted panicles.
- The third glume is thin and membranous, awnless. 32. Sporobolus.
Chlorideæ 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 bisexual. 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 clusters, awned. 33. Gracilea.
- Spikelets 1- to 2-flowered, not clustered 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.
- Spikes usually solitary.
31. Aristida, L.
These are tufted, annual or perennial grasses. 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, acuminate, 3-nerved, tip produced into a long 3-partite, 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 tripartite 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.
- Glumes I and II not awned.
- 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.
- Annual.
- Awn with a long column, tripartite at the top.
- Annual; panicle lax, narrow; glumes I and II awned. 5. A. funiculata.