7. Cenchrus, Linn.

Annual or perennial grasses, usually tall. Leaves flat, flaccid. Spikelets narrow, with a single terminal hermaphrodite flower with or without a male flower below it, enclosed 1–4 together in an ovoid or globose involucre of numerous bristles or spines, the inner of which are broad and flattened, connate at the base and hardened in fruit; the involucres sessile in a terminal spike or raceme, and deciduous with the spikelets. Glumes 4; the outer much the smallest, sometimes minute, empty; 2nd equalling the 3rd or a little shorter, empty; 3rd usually containing a palea and sometimes 3 stamens; 4th or flowering glume rather shorter than the 3rd and more rigid. Stamens 3. Styles often connate at the base. Grain enclosed in the flowering glume and palea, free from them.

Species about 12, in the warm regions of both hemispheres and in temperate North America.