Usually robust, tall annuals or perennials. Leaf-sheath open. Ligule membranous, ciliate. Leaf-blade usually flat, often large. Culm simple. Panicle large, open, erect or ± nodding, or densely contracted in cultivated grain-bearing spp., with strong rachis and rather slender verticillate or scattered branches, each bearing several racemes with paired dissimilar spikelets, the terminal group of spikelets a triplet; each pair consisting of one sessile and one pedicelled spikelet, the sessile spikelet falling with the contiguous rachis segment and accompanying pedicelled spikelet, or at least with its pedicel, or persistent. Spikelets 2-flowered, lower floret in all spikelets Ø and reduced to an empty lemma, upper floret ☿ in sessile spikelet, ♂, Ø or 0 in pedicelled spikelets. Pedicelled spikelets: narrower than sessile spikelets; glumes lanceolate, herbaceous; lemma awnless; palea 0; sometimes reduced to both glumes or 1 glume. Sessile spikelets: glumes equal, coriaceous and shining at maturity, muticous; lower 5-11-nerved, flattened or rounded, margins involute, upper naviculate, 3-11-nerved, keeled above, margins narrow, hyaline, usually ciliate; lemmas and palea hyaline, enclosed by glumes; lemma of lower floret 2-nerved or nerveless; lemma of upper floret 1-3-nerved, apex ± lobed, awned or mucronate from sinus, rarely muticous; palea often minute or 0; lodicules 2, ciliate or glabrous; stamens 3; ovary apex glabrous, styles ± terminal, free, stigmas laterally exserted; caryopsis free in anthoecium, embryo c. ½ length of caryopsis, hilum punctiform or shortly elliptic, < ½ length of caryopsis.