Description from Flora of China
Annuals. Leaf blades narrowly linear to linear-lanceolate. Inflorescence a slender cylindrical raceme, spikelets sessile in 2 alternating rows sunk in hollows of the rachis; rachis fragile, fracturing horizontally beneath each spikelet at maturity. Spikelets with 1 floret; glumes leathery, placed side by side in front of spikelet and appressed to rachis, closing rachis cavity and covering floret, asymmetrical, appearing like halves of a single split glume, strongly 3–7-veined, outer margin inflexed, apex acute; lemma hyaline, 3-veined, its side toward the rachis, awnless; palea slightly shorter than lemma. Ovary with lobed apical appendage; styles nearly absent. Caryopsis narrowly oblong; hilum round to narrowly oblong. Endosperm liquid.
Six species: C and SW Asia, Mediterranean region, northward along Atlantic coast of Europe to the Baltic Sea; introduced to most other temperate regions; one species (introduced) in China.
(Authors: Wu Zhenlan (吴珍兰); Sylvia M. Phillips)