偃麦草 yan mai cao

Plants with long rhizomes. Culms not tufted, green, glaucous, or purplish green, 40–80 cm tall, 3–5-noded, smooth. Leaf sheath smooth, glabrous but pilose at base; ligule ca. 0.5 mm; leaf blade flat, 10–20 × 0.5–1 cm, abaxial surface smooth, adaxial surface scabrous or pilose. Spike erect, 10–18 × 0.8–1.5 cm; rachis smooth but margin hispidulous; internodes 10–15 (–30) mm. Spikelets 10–18 × 6–10 mm, with 5–7(–10) florets, glabrous. Glumes subequal, 4–15 mm, 5–7-veined, smooth, glabrous, margin membranous, apex with point 1–2 mm or awn 4–8 mm. Lemma oblong-lanceolate, 6–12 mm, apex acuminate or with awn to 2 mm or 4–8 mm. Palea slightly shorter than lemma, ciliolate along keels. Anthers yellow, ca. 5 mm. Fl. and fr. Jun–Sep.

Valleys, grasslands, pastures, meadows, field margins, waste places; 500–1900 m. Gansu, Hebei, Heilongjiang, Nei Mongol, Qinghai, Shandong, Sichuan, Xinjiang, Xizang, Yunnan [India, Japan, Korea, Mongolia, Russia; C and SW Asia, Europe; introduced in North America].

This species is one of the world's most valuable range grasses.