Panicum L.
Type species: P. miliaceum L.
Perennials, or annuals, of various habit. Leaf-sheath open, or closed below. Ligule usually a membranous ciliate rim. Leaf-blade usually flat, rolled in bud. Culm simple or branched. Inflorescence a panicle of variable form, often spreading and much-branched, with fine branches tipped by single pedicelled spikelets falling entire at maturity. Spikelets lanceolate to oblong, elliptic or orbicular, usually ± dorsally compressed, 2-flowered, florets awnless; lower floret Ø, or ♂ and then with distinct palea; upper floret ⚥. Glumes ± herbaceous to membranous, usually very unequal; lower usually shorter, 1-7-nerved, upper usually = spikelet, 3-9-nerved. Lower floret: lemma similar to upper glume in size and texture, (3)-5-9-(11)-nerved; palea subhyaline, ≤ lemma, or 0. Upper floret: lemma subcoriaceous, usually glabrous, obtuse to subacute, rarely minutely apiculate, only faintly nerved, margins inrolled over palea; palea < lemma and similar in texture, lower margins incurved over flower; lodicules 2, broadly cuneate; stamens 3; ovary apex glabrous, styles subterminal, free; caryopsis tightly enclosed by anthoecium, dorsally compressed, biconvex to almost planoconvex; embryo large, at least ⅓ length of caryopsis; hilum punctiform or shortly elliptic, < ½ length of caryopsis.
Key
Possibly over 500 spp. of tropical, subtropical and warm temperate regions. Naturalised spp. 7; transient sp. 1.