Setaria

Annual or perennial, caespitose or decumbent, sometimes rhizomatous or stoloniferous. Leaf blade expanded or folded, rarely rolled, sometimes pleated longitudinally, occasionally saggitate; ligule a fringed membrane or fringe of hairs. Inflorescence a panicle, open or usually spike-like, then dense and cylindrical with branches reduced to stumps; spikelets solitary or clustered, shortly pedicelled or subsessile, each spikelet or cluster subtended by 1 to many bristles, these persist on axis after spikelet falls, bristles either shorter or longer than spikelet, scabrid, often coloured; spikelets when clustered usually not all fully developed. Spikelet elliptic to oblong to ovate, compressed dorsiventrally, falling with glumes (not disarticulating in cultivated forms); glumes unequal, membranous, awnless; lower glume up to half as long as spikelet, ovate from clasping base, 3-6-nerved; upper glume a third up to as long as spikelet, 3-9-nerved. Florets 2; lower floret male or sterile; lemma as long as spikelet, 5-7-nerved, rounded, flat, or longitudinally grooved dorsally, awnless; palea well developed or minute to 0; upper floret bisexual; lemma firmer than glumes, usually indurated, often finely or coarsely transversely rugose, more rarely smooth and glossy, glabrous, entire, margins inrolled and clasping only edges of palea, awnless; palea similar to lemma, relatively long. Lodicules 2, broadly cuneate. Stamens 3. Ovary ellipsoid, glabrous; styles distinct, plumose above. Caryopsis oblong or ellipsoid. x= 9, 10 (high polyploidy).