Cenchrus 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.

[From: Edgar and Connor (2000) Flora of New Zealand. Volume 5 (second printing).]