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ECHINOCHLOA Beauv. Cockspur
Plants caespitose, annual or perennial. Culms ascending or geniculate, glabrous; internodes solid, terete.
Leaves not differentiated into two kinds (basal rosette absent), cauline, not distinctly distichous; sheaths
terete; ligules absent or a line of hairs; blades flat. Panicles open or contracted,
spicate primary unilateral branches (occasionally rebranching), alternate; primary branches spreading or
ascending or appressed, terminating in a spikelet; bristles absent below spikelets. Spikelets solitary
or paired, not embedded in branch, adaxial, dorsiventrally compressed or planoconvex; disarticulation
below spikelets; florets 2; lower sterile and staminate or without stamens; upper fertile more than eight
tenths lower floret length; first glumes present, not fused with callus, encircling spikelet base,
awnless or mucronate; second glumes present (rounded on back), nine tenths or more times spikelet length, not
saccate, 5- or 7- or 9-veined; lemma of upper florets indurate, smooth, yellow, glabrous or
scabrous, margins involute, differentiated at apex, awnless; palea of upper florets present. Stamens 3;
anthers yellow or reddish brown or tan or yellowish brown. Base chromosome number x=9.
A taxonomically difficult genus of about 40 species that occur in warm regions of the world. Gould et al.
(1972) revised the genus for the United States and later Michael and Vickery (1975, 1980) studied Austro-Asian
species.
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