Annuals, or rarely biennials, or perennials, herbaceous, long-stoloniferous, sometimes mat-forming or tufted. Ligule membranous, glabrous or very rarely minutely ciliate. Inflorescence of spike-like racemes bearing secund, ± sessile, adaxial spikelets ± embedded in the flattened, hollowed or winged rachis and mostly solitary at nodes, falling entire at maturity. Spikelets 2-flowered, dorsally compressed; lower floret Ø, upper floret ☿. Lower glume 0, upper = spikelet, membranous, 4-5-nerved. Lower floret: lemma ≤ glume, membranous. Upper floret: lemma shorter, chartaceous to crustaceous, ± mucronate, glabrous, 4-nerved; palea ≤ lemma. Lodicules 2, fleshy, glabrous. Stamens 3. Ovary apex glabrous; styles subterminal, free. Caryopsis dorsiventrally compressed, glabrous; embryo large, at least ⅓ length of caryopsis; hilum punctiform or shortly elliptic, < ½ length of caryopsis.