Description from Flora of China
Nazia Adanson, nom. rej.
Annuals or perennials. Leaf blades narrow, flat; ligule a line of hairs, sometimes from a membranous base. Inflorescence linear, cylindrical, spikelike, dense, axis bearing numerous very short racemes; racemes subsessile or shortly pedunculate, falling entire as spiny burrs; spikelets 2–5, contiguous or on a short rachis, sometimes the upper reduced. Spikelets elliptic to lanceolate, floret 1; lower glume a tiny scale or suppressed; upper glume as long as spikelet, rounded, prominently 5–7-veined, veins forming ribs armed with conspicuous, stout, hooked spines, thin between ribs, apex acute to acuminate; lemma ovate, almost as long as glume, flattened, membranous, 3-veined, pubescent around midvein, apex entire; palea slightly shorter than lemma. Caryopsis ellipsoid to oblong, slightly dorsally compressed.
Both species occurring in China have been confused with the Mediterranean, African, and SW Asian Tragus racemosus (Linnaeus) Allioni, which differs in having 7 veins (vs. 5) in the upper glume.
Seven species: tropical and warm-temperate regions of the Old World; introduced in America; two species in China.
(Authors: Chen Shouliang (陈守良); Sylvia M. Phillips)