西南莩草 xi nan fu cao

Perennial from a knotty rootstock. Culms rigid, erect or geniculate, 60–170 cm tall, 2–4 mm in diam., glabrous. Leaf sheaths glabrous, margins densely ciliate with silky hairs; leaf blades broadly linear or linear-lanceolate, 10–40 × 0.4–2 cm, glabrous, base subrounded or cuneate, apex acuminate; ligule ca. 3 mm. Panicle open, linear to narrowly pyramidal, 10–40 cm, erect or slightly nodding, branches spaced, ascending, lowest 0.5–2 cm, spikelets subtended by a single bristle; axis scabrous to hispid; bristles 3–4 times spikelet length, stout, stiff green or purple. Spikelets elliptic or ovate, 2.8–3.2 mm, strongly veined; lower glume broadly ovate, 1/3–1/2 as long as spikelet, acute; upper glume 2/3–3/4 as long as spikelet, (5–)7–9-veined; lower floret staminate, as long as upper floret; lower palea well developed; upper lemma finely punctate-rugose. Fl. and fr. Jul–Oct.

Mountain slopes, valleys, roadsides, streams; 300–2000 m. Anhui, Gansu, Guangdong, Guangxi, Guizhou, Henan, Hubei, Hunan, Shaanxi, Sichuan, Yunnan, Zhejiang [Bhutan, N India, Myanmar, Nepal].