Annual or perennial herbs, usually with slender culms. Leaf-blades usually narrow, flat; ligule membranous. Inflorescence an open or contracted, sometimes spike-like, panicle. Spikelets all alike, hermaphrodite, 1-flowered; rhachilla disarticulating above, or rarely below, the glumes, sometimes produced beyond the floret as a slender bristle; glumes usually persistent, mostly as long as or longer than the lemma; lemma hyaline to membranous, 3–5-nerved, commonly with a geniculate dorsal awn, less often awnless, straight-awned, or awned from the 2-lobed tip; palea usually delicate, often small or wanting, 2-nerved; lodicules 2, rarely 0; stamens 1–3; stigmas 2. Grain with small embryo and linear hilum; starch grains compound. Leaf anatomy: chlorenchyma diffuse; bundle-sheaths double; silica-bodies oblong; 2-celled hairs absent; stomatal subsidiary cells parallel-sided or low dome-shaped. Embryo poöïd. Chromosomes large, basic number 7.