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. 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. 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, tripartite at the top. Annual; panicle lax, narrow; glumes I and II awned. 5. A. funiculata. [Illustration: Fig. 171.--Aristida Adscenscionis.] =Aristida Adscenscionis, _L._= This grass 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.