Setaria P.Beauv.
Type species: S. viridis (L.) P.Beauv.
Usually tufted annuals or perennials, of medium height. Leaf-sheath open, or closed near base, often keeled. Ligule a ciliate rim. Leaf-blade flat to folded, rolled in bud. Culm erect, or ascending from geniculate base. Inflorescence usually an erect, dense, cylindric, spike-like panicle, or more branched and open, each spikelet subtended by one to several persistent scabrid bristles (Ø branchlets) almost to entirely suppressed in plants with plicate leaves (S. palmifolia). Spikelets 2-flowered, usually falling entire at maturity; lower floret ♂ or Ø, upper floret ⚥. Glumes membranous, unequal, glabrous, lower generally the shorter, upper ≤ spikelet. Lower floret: lemma of same texture as glumes, = spikelet, dorsally flattened to slightly depressed; palea sometimes 0. Upper floret: lemma ≤ spikelet, crustaceous, often rugose, naviculate; palea ≈ lemma and similar in texture; lodicules 2, broadly cuneate, rather fleshy; stamens 3; styles free; caryopsis tightly enclosed by hardened anthoecium, embryo c. ½ length of caryopsis, hilum basal, punctiform or orbicular.
Key
c. 140 spp., of tropical and warm temperate regions, often weedy. Naturalised spp. 7; transient sp. 1.
