Annuals. Leaf-blades usually flat, sometimes rolled. Inflorescence a spike. Spikelets solitary at the nodes of the fragile or rarely tough rhachis, all bisexual or the upper sterile and the lower vestigial; florets 4-8, the upper male or vestigial; glumes equal, coriaceous, truncate or often with 1 or more teeth or awns, usually rounded on the back; lemma thin below, coriaceous and strongly nerved towards the toothed or awned tip; palea 2-keeled.