Cenchrus L.
Type species: C. echinatus L.
Annuals or perennials. Leaf-sheath compressed. Ligule reduced to ciliate rim. Leaf-blade flat or involute. Culm terete, solid. Inflorescence a solitary spike-like panicle of prickly glomerules, composed of coalescing spines; spikelets sessile, solitary, or in clusters of 2-5 surrounded by, and deciduous with the sessile or minutely peduncled involucre of ± connate, often rigid, antrorsely or retrorsely scabrid spines or bristles. Spikelets 2-flowered; lower floret ♂, or Ø and reduced to a lemma, upper floret ⚥. Glumes usually dissimilar, rarely subequal, hyaline or thinly membranous; lower often 0, or if present, 1-5-nerved, upper ≤ spikelet, 1-5-(7)-nerved. Lower floret: lemma usually similar in texture to upper glume and ≈ spikelet, 3-7-nerved; palea ≈ lemma, 2-keeled. Upper floret: lemma = spikelet, firmly membranous, chartaceous or coriaceous, 5-7-nerved; palea = lemma; lodicules 0; stamens 3; ovary apex glabrous, styles terminal, free, or connate below; caryopsis dorsiventrally compressed, glabrous, embryo c. ⅔ length of caryopsis, hilum basal, punctiform.
c. 25-30 spp., of tropical and warm temperate dry regions of America, Africa, India, south-western Asia, Polynesia, and Australia. Indigenous sp. 1.
Some spp. of Cenchrus are common weeds and may become serious pests on account of the scabrid spines of their involucres.
