Description from Flora of China
Andropogon annulatus Forsskål, Fl. Aegypt.-Arab. 173. 1775; Bothriochloa tuberculata W. Z. Fang; Dichanthium annulatum var. bullisetosum B. S. Sun & S. Wang.
Perennial. Culms tufted, erect or sometimes straggling, 30–100 cm tall, nodes bearded with spreading hairs. Leaf sheaths terete, shorter than internodes; leaf blades flat, 8–30 × 0.2–0.4 cm, glabrous or adaxial surface stiffly pilose, margins smooth or scaberulous, apex acuminate; ligule 1–2 mm, lacerate. Inflorescence terminal; peduncle glabrous; racemes 2–8, subdigitate, suberect, 4–5 cm, with 0–6 pairs of homogamous spikelets. Sessile spikelet 3–5 mm; lower glume elliptic-oblong or oblong, firmly papery, 5–9-veined, subglabrous or pubescent to villous on lower back, upper flanks often with long spreading hairs, keels shortly ciliate, not or barely winged, apex obtuse; upper glume ciliate along keel and margins, apex acute or obtuse; awn 1.6–2.4 cm. Caryopsis obovate. Pedicelled spikelet many-veined, pubescent to villous with spreading tubercle-based hairs. Fl. and fr. Jun–Nov. 2n = 20, 40.
Mountain slopes, disturbed ground; 100–2200 m. Guangdong, Guangxi, Guizhou, Hainan, Hubei, Sichuan, Taiwan, Yunnan [India, Indonesia, Malaysia, Myanmar, Nepal, Pakistan, Philippines; Africa, Pacific Islands; introduced in America and Australia].