Annuals or perennials, culms erect or creeping at base; ligule a short fringe of hairs. Leaf blade linear
with broad base and acute apex, flat or rolled. Inflorescence racemose-paniculate, composed of
racemes, arranged on all sides of main axis; lower racemes often pedunculate; rachis of racemes keeled
on abaxial side. Spikelets pedicelate, alternately arranged along keel, upper part of raceme solitary, middle
part often paired, alternately arranged along keel, lower part of larger racemes often in short biseriate
racemes, pedicels of a pair unequal, fused at base; spikelets articulate with widened apex of pedicel,
oblong, dorsally compressed, 2-flowered, base of spikelet swollen, konb-like or cupuliform, usually
reddish, bearing lower glume; lower glume small and veinless or absent; upper glume as long as spikelet,
acute or mucronate or shortly awned, 5-veined; lower lemma as long as upper glume or slightly
shorter, acute or mucronate, 5-venied; lower palea present or absent; stamens 3 or absent; upper lemma
always shorter than spikelet, adaxial, with rounded apex, mucronate or with short awn, chartaceous with
narrowly incurved, opaque margins; upper palea chartaceous, flat, tuberculate, broad, inflexed, smooth;
lodicules 2, small, truncate; stamens 3, anthers linear; styles 2, free, stigmas plumose, laterally exserted.
Caryopsis free between indurate upper lemma and upper palea, elliptic, dorsally compressed, embryo 1/
2 as long as fruit, hilum oblong.
About 30 species distributed in the tropical and subtropical regions of the world. Two species in
Taiwan.
