少穗落芒草 shao sui luo mang cao

Oryzopsis hilariae (Pazij) Uniyal; O. humilis Bor; O. wen-delboi Bor; Piptatherum humile (Bor) S. Kumar & M. B. Raizada.

Perennial, densely tufted. Culms 20–50 cm tall, 2–3-noded. Leaf sheaths glabrous, usually shorter than internodes; leaf blades gray-green or gray purple, usually rolled, rarely flat, up to 10(–30) cm, 2–4 mm wide, abaxial surface smooth or scaberulous, adaxial surface puberulous; ligule lanceolate, 3–6 mm. Panicle open or contracted, 5–12(–30) cm; branches 2 per node, spreading at anthesis, erect at maturity, longest less than 1/2 panicle length. Spikelets purplish red or gray-green; glumes lanceolate-ovate, 5–8 mm, apex sharply acuminate; callus glabrous; lemma elliptic to narrowly ovate, 3.5–4 mm, back pubescent with 0.2–0.3 mm hairs, midline glabrescent at maturity, apex usually shortly beaked, pale, glabrous, shortly 2-lobed above awn insertion, lobes rounded, each with tuft of hairs; awn caducous, 2–4 mm, often slightly bent at insertion. Anthers 1.5–2.5 mm, glabrous at apex or almost so. Fl. and fr. Jun–Sep.

River banks, plateaus; 3100–4500 m. Xizang (Lhozhag, Qusum) [E Afghanistan, NW India, Kashmir, Pakistan, Tajikistan (Pamirs)].

This species is close to Piptatherum gracile, but has an abruptly narrowed lemma apex, and the short apical hair tufts are distinctive. It is the only species of Piptatherum in China (except for the distinctive P. kuoi) with glabrous anthers (1 or 2 short hairs may be present, but never a dense tuft). In neighboring countries it occurs in the upper forest belt and in alpine thickets.

The name Piptatherum humile refers to small specimens with linear panicles.