Echinochloa

Annual or perennial, sometimes rhizomatous, tufted to decumbent or floating. Leaf blade usually expanded; ligule a fringe of hairs or 0. Inflorescence of few to many spike-like racemes crowded or scattered on central axis, racemes usually 1-sided and dense, sometimes spike-like, rachis triquetrous; spikelets paired or clustered on short branchlets forming (2-)4 or more rows, subsessile or shortly pedicelled, adaxial. Spikelet 1.5-7.0 mm long, dorsiventrally compressed, gibbous on one side and flat on other (plano-convex), +/- hispidulous or hispid, rarely minutely softly hairy, cuspidate to awned, falling with glumes; glumes unequal, membranous; lower glume usually much smaller than upper, ovate, with a clasping base, usually distinctly 0-3-nerved, acute to acuminate, often mucronate; upper glume as long as spikelet, ovate, 5-7-nerved, nerves usually hispid, mucronate (cuspidate) or shortly awned. Florets 2; lower floret male or sterile; lemma similar to upper glume, 5-nerved, awnless or awned; awn as long as or up to 3 x as long as lemma, palea hyaline or 0; upper floret bisexual; lemma firmer than glumes, coriaceous, smooth and shiny, glabrous, convex, entire, margins inrolled and clasping only edges of palea, awnless; palea similar to lemma, indurated with infolded margins, acute tip briefly reflexed and +/- protuberant between lemma margins. Lodicules 2, cuneate, fleshy. Stamens 3. Ovary glabrous; styles distinct, plumose above. Caryopsis broadly ellipsoid, dorsally flattened. x= 9 (high polyploidy).