Annuals or perennials, mostly robust. Leaf-blades linear, never aromatic; ligule membranous or reduced to a ciliate rim. Inflorescence composed of paired or digitate (rarely solitary) racemes, terminal on the culm or axillary, in the latter case often numerous and crowded into a spatheate false panicle; racemes fragile and bearing paired spikelets, very rarely deflexed at maturity. lacking basal sterile (homogamous) spikelet pairs or these scarcely differentiated from the rest; internodes and pedicels filiform to obovoid, ciliate to plumose (rarely glabrous). Sessile spikelet 2-flowered, falling entire; callus obtuse, inserted into the concave tip of the internode; lower glume membranous to coriaceous, flat, concave or deeply grooved on the back, 2-keeled, the keels lateral or dorsal, with or without intercarinal nerves; upper glume awned or not; lower floret reduced to a hyaline lemma; upper floret bisexual, the lemma hyaline, often stipitiform, bilobed, passing between the teeth into a conspicuous awn with glabrous or puberulous column; palea small or absent; caryopsis narrowly lanceolate to oblong, subterete or planoconvex. Pedicelled spikelet male or barren (occasionally suppressed), never concave on the hack, usually awnless.