Description from Flora of China
Annual or perennial. Leaf blades linear, flat; ligule membranous. Inflorescence a spikelike panicle, densely cylindrical, spikelets numerous, closely packed; pedicels very short, apices cuplike. Spikelets protogynous, strongly laterally compressed, floret 1, falling entire from pedicel; rachilla extension absent; glumes equal, ± equaling and enclosing floret, broadly lanceolate to oblong, membranous to thinly leathery, prominently 3-veined, strongly keeled, keel usually ciliate, infrequently winged, lower margins almost free or connate for up to half their length, apex obtuse, acute or shortly awned; lemma broadly lanceolate to ovate, usually thinly membranous, keeled, obscurely 5-veined, smooth, glabrous, lower margins often connate, awned from lower back, apex truncate to acute; awn straight when short or geniculate when longer, column smooth, usually twisted at maturity, bristle scabrid; palea absent or very small. Lodicules absent; ovary glabrous. Caryopsis obliquely obovate in side view; endosperm sometimes liquid.
Between 40 and 50 species:temperate and cold regions of the N hemisphere, South America; eight species in China.
(Authors: Lu Shenglian (卢生莲); Sylvia M. Phillips)