Cenchrus Linn., Sp. Pl. 2:1049. 1753. Gen. Pl., ed. 5, 470. 1754; Boiss., Fl. Or. 5:447. 1884; Hook. f., Fl. Brit. Brit. Ind. 7:89. 1896; Blatter & McCann, Bombay Grasses 185. 1935; Tackholm & Drar, Fl. Egypt 1:474. 1941; Sultan & Stewart, Grasses W. Pak. 1:57. 1958; Bor, Grasses Burma Ceyl. Ind. Pak. 287. 1960; DeLisle in Iowa St. J. Sci. 37: 259. 1963; Bor in Towns., Guest & Al-Rawi, Fl. Iraq 9:474. 1968; Bor in Rech. f., Fl. Iran. 70:504. 1970; Tzvelev, Poaceae URSS 684. 1976; Clayton in Tutin et al., Fl. Eur. 5: 264. 1980.
Annuals or perennials. Leaf-blades flat or involute; ligule a line of hairs. Inflorescence a cylindrical spike-like panicle with an angular rhachis, each spikelet or cluster of spikelets enclosed by a deciduous involucre; involucre composed of 1 or more whorls of bristles, these ± flattened and often spiny, connate at the base for some distance along their length. Spikelets .lanceolate to ovate, dorsally compressed, acute to acuminate; lower glume up to half as long as the spikelet, sometimes suppressed; upper glume a little shorter than the spikelet; lower floret male or barren, its lemma as long as the spikelet, membranous; upper lemma as long as the spikelet, firmly membranous to coriaceous, the margins covering up to two-thirds of the palea. Caryopsis & elliptic to ovoid, dorsally compressed.
A genus of 22 species in tropical and warm temperate regions, mainly in Africa and America; 5 species occur in Pakistan.
Cenchrus is distinguished from Pennisetum by the transformation of the involucral bristles into a spiny cup. The tendency is barely recognisable in Cenchrus ciliaris, whose membership of the genus is justified by its intergradation with Cenchrus pennisetiformis.