Cenchrus

Annual or perennial. Leaf blade expanded, folded, or involute; ligule a fringed membrane to a fringe of hairs. Inflorescence a cylindrical spike-like panicle; each spikelet or cluster ofspikelets enclosed by a deciduous involucre composed of 1 or more whorls of bristles, bristles joined at base, forming a disc below spikelet or some distance above, bristles sometimes +/- flattened and/or hardened to form rigid spines enclosing spikelets, thus forming burrs. Spikelet lanceolate to ovate, dorsiventrally compressed, acute to acuminate; glumes unequal, awnless; lower glume up to half as long as spikelet, hyaline or membranous, 1-5-nerved; upper glume a little shorter than spikelet, 1-7-nerved. Florets 2; lower floret male or sterile with lemma as long as spikelet, membranous, acuminate, 3-7-nerved, awnless, palea similar to lemma, hyaline; upper floret bisexual, lemma as long as spikelet, similar to firmer than glumes, membranous to chartaceous, not indurated, 5-7-nerved, entire, smooth, flat, with thin margins covering much of palea; palea similar to lemma, hyaline. Lodicules 0 or abortive. Stamens 3. Ovary ovoid; styles plumose above. Caryopsis ellipsoid to ovoid, dorsiventrally compressed. x= 9, 12 (aneuploids, polyploidy).