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UROCHLOA Beauv. Signalgrass
Plants caespitose or rhizomatous or stoloniferous, annual or perennial. Culms erect or ascending or decumbent,
glabrous or pubescent, internodes solid or hollow, terete. Leaves not differentiated into two kinds (basal
rosette absent), basal and cauline, not distinctly distichous; sheaths terete; ligules a line of hairs or
ciliate membrane; blades flat or involute. Panicles open or of spicate primary unilateral branches
; primary branches frequently alternate, spreading to ascending, terminating in a spikelet; bristles
absent below spikelets. Spikelets solitary or paired, not embedded in branch, adaxial or abaxial,
planoconvex or dorsiventrally compressed; disarticulation below spikelets; florets 2; lower florets sterile
and staminate or without stamens; upper florets fertile, more than three fourths lower floret
length; first glumes present (short), not fused with callus, encircling spikelet base, awnless; second
glumes present (rounded on back), nearly equal to spikelet length, not saccate, 5-11-veined; lemma of upper
florets indurate, rugose, yellowish, glabrous, margins involute, not differentiated at apex, awnless
or mucronate or awned; palea of upper florets present. Stamens 3; anthers yellow. Base chromosome
number x=7,9,10.
A morphologically variable genus of about 110 species.
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