Annuals or perennials; culms hollow. Ligule short, truncate, ciliolate; blades flat or rolled, acute or obtuse, not narrowed at base or with short pseudo-petiole, margins revolute when dry, and often discoloring to a rusty-red or scarlet. In-florescence a spike-like raceme, usually few-jointed, terminating flowering-twigs consisting of a raceme, peduncle, subtending leaf, and next-lower internode. Spike-in alternate pairs, dimorphic, 1 pedicelled, 1 sessile, dorsiventrally arranged. Sessile spikelets oblong, usually dorsally compressed, falling with the adjacent pedicel and rachis-joint; lower glume as long as spikelet, usually coriaceous, margins incurved to inflexed, shortly 2-toothed at the apex, 5-7-nerved or nerves obscure muticous or with short subula, not keeled or with 2-keels, and these sometimes excurrent into very short awns; upper glume about as long as lower glume, boat-shaped-keeled, membranous, 1-nerved, muticous; lower lemma shorter, thinly membranous, nerveless or 2-nerved; lower palea absent; upper lemma deeply divided into acute narrow lobes, thinly membranous, with a geniculate awn from the sinus: upper palea wanting; lodicules 2, cuneate, with emarginate apex; stamens 3; styles 2, free. Caryopsis linear-oblong to spindle-shaped. Pedicelled spikelets well- or poorly developed.
About 50 species distributed in the tropical regions of the world.
Two taxa with one variety are found in Taiwan.