Description from Flora of China
Perennial. Leaf sheaths closed to middle; leaf blades linear, flat or folded. Inflorescence a lobed, 1-sided panicle, open or contracted; spikelets subsessile, densely clustered in compact fascicles on the panicle branches. Spikelets strongly laterally compressed, florets 2–5, disarticulating above glumes and between florets; glumes lanceolate, subequal, shorter than lemmas, strongly keeled, 1–3-veined; lemmas lanceolate to oblong in side view, papery or thinly leathery, strongly keeled, 5-veined, scabrid or ciliate along keel, apex cuspidate to briefly awned; palea slightly shorter than lemma, narrow, ciliolate along keels. Caryopsis oblong or slightly triangular; hilum round; endosperm soft.
One widespread, variable species is recognized here. There are many different races and ecotypes throughout its range, the more widespread being generally tetraploid with local diploid races particularly in the Mediterranean region. These forms are seldom clear-cut, and intermediates are common.
One species: N Africa, temperate Asia, Europe; widely introduced elsewhere as a pasture grass.
(Authors: Lu Shenglian (卢生莲); Sylvia M. Phillips)