Perennials or annuals, rhizomatous, stoloniferous or tufted. Ligule membranous, entire or lacerate, usually glabrous. Leaf-blade flat, scabrid. Culm erect, or decumbent and straggling, terete or compressed. Panicle open or contracted, enclosed by leaf-sheaths or exserted, terminal or axillary. Spikelets 1-flowered, ☿, strongly laterally compressed; lower lemmas suppressed, rachilla modified to a short callus-like segment at base of deciduous floret; disarticulation above rudimentary glumes. Lemma chartaceous to coriaceous, keeled, 5-nerved with the outer lateral nerves ± at margins, usually awnless, keel and margins stiffly toothed. Palea similar in texture to lemma, much narrower, margins tightly enclosed by lemma margins. Stamens 6, or 3, 2, or 1.