RLEM 610 grass taxonomy axonopus

DIGITARIA Fabr. Crabgrass, Cottontop Plants caespitose or rhizomatous or stoloniferous, annual or perennial. Culms erect or ascending or decumbent (branching above base), glabrous or pubescent or hairy; internodes hollow or solid, terete. Leaves not differentiated into two kinds (basal rosette absent), basal and cauline, not distinctly distichous; sheaths terete; ligules membranous or a ciliate membrane; blades flat (thin) or folded. Panicles open or contracted or of numerous spicate primary branches or spicate primary unilateral branches; primary branches alternate or paired or subdigitate or digitate, terminating in a spikelet; bristles not subtending spikelets. Spikelets solitary or in pairs or ternate, not embedded in branch, abaxial, planoconvex; disarticulation below spikelets; florets 2; lower sterile without stamen; upper fertile, one half or longer than lower floret; first glumes present or absent, not fused with callus, not encircling spikelet base, awnless; second glumes present (rounded on back), 0.3-1 times spikelet length, not sacate, 1- or 3- or 5-veined, one half to longer than floret length; lemmas of upper floret cartilaginous, smooth or striate or muricate, grey or brown or black or yellow, glabrous, margins flat, not differentiated at apex, awnless or mucronate; paleas of upper florets present. Stamens 3; anthers brown or golden. Base chromosome number x=9. A morphologically variable genus of about 250 species with many important weeds and many important forage species.