Annuals or perennials; culms filled with pith, glabrous; strongly tufted or partly creeping and/or
floating; ligule a fringe of hairs or absent. Inflorescence a panicle composed of spike-like racemes, racemosely
arranged or slightly branched; racemes arranged on all sides of main axis, uppermost short,
mostly secund and dense, main axis ending in a few spikelets. Spikelets flat on side of lower glume,
other side strongly convex, broadly elliptic, abruptly acuminate, awned or muticous, hairy, sessile or
shortly pedicelate, sometimes in pairs, sometimes to 4(-10) together, falling as a whole, 2-flowered;
pedicels 0.5-1 mm long, widened at apex; rachilla not produced; glumes and lower lemma herbaceous;
lower herbaceous, indurate at maturity; lower glume 1/5-3/5 as long as spikelet, ovate-oblong, acute orshortly awned, distinctly veined; upper glume as long as spikelet, ovate-oblong, acute, 5-veined, muticous
or with short straight awn; lower palea slightly shorter, with 2 cilate veins; stamens present or
absent; upper lemma strongly convex, smooth and glossy, embracing upper palea with narrowly
incurved opaque margins, acuminate or with short awn; upper palea as long as and of same texture; stamens
3; ovary glabrous, styles 2, free, stigmas plumose, purple, laterally exserted. Caryopsis free,
wholly enclosed between upper palea and upper lemma, elliptic, plano-convex, hilum punctiform, basal.
About 30 species distributed in the warmer regions of the world. Three species in Taiwan.