二穗短柄草 er sui duan bing cao

Bromus distachyos Linnaeus, Cent. Pl. 2: 8. 1756; Agro-pyron distachyon (Linnaeus) Chevallier; Festuca distachya (Linnaeus) Roth; Trachynia distachya (Linnaeus) Link; Zerna distachya (Linnaeus) Panzer ex B. D. Jackson.

Annual. Culms tufted, usually ascending, infrequently erect, up to 15(–40) cm tall. Leaf sheaths loosely to densely pilose; leaf blades lanceolate, flat, rather stiff, glaucous, 1–12 cm, 3–4 mm wide, loosely pilose, margins scabrous-pectinate, apex acuminate; ligule ca. 1 mm. Raceme 2–4 cm, spikelets 1–3 crowded at apex of peduncle. Spikelets 2–3 cm, laterally compressed, florets 10–16; glumes pilose or glabrous, apex acute, lower glume lanceolate, 5–6 mm, 5-veined, upper glume lanceolate-oblong, 7–8 mm, 7-veined; lemmas 7.5–10 mm, glabrous, thinly setose or pubescent; awn 7–15 mm. Anthers 0.5–1 mm.

Dry stony places. Xizang (Mainling) [Afghanistan, Pakistan, Tajikistan, Turkmenistan; N Africa, SW Asia, S Europe; introduced elsewhere].