Perennials with membranous ligule. Inflorescence a terminal group of numerous racemes borne on a short common axis; rhachis internodes columnar to inflated.   Sessile spikelet: callus truncate, flat or with a central peg; lower glume smooth or muricate, keel winged or not; lower floret male or barren; upper lemma entire and awnless.  Pedicellate spikelet usually resembling the sessile spikelet but smaller, occasionally vestigial.