PANICUM L. Panicum
Plants caespitose or rhizomatous or stoloniferous, annual or perennial. Culms erect or ascending or decumbent
or geniculate, glabrous; internodes solid or hollow, terete. Leaves not differentiated into two kinds
(without basal rosette), basal or cauline or basal and cauline, not distinctly distichous; sheaths usually
terete or occasionally with compressed keels; ligules a membrane or ciliate membrane; blades flat
or folded. Panicles open or contracted; 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 laterally compressed; disarticulation below spikelets;
florets 2; lower sterile staminate or without stamen, upper fertile, about shorter than lower lemma;
first glumes present, not fused with callus, encircling spikelet base, awnless; second glumes present
(rounded on back), 1 times spikelet length, not saccate; lemma of upper florets indurate or
cartilaginous, smooth to muricate, white to brown or yellow, glabrous, margin involute, not
differentiated at apex, awnless; palea of upper florets present. Stamens 3; anthers tan or amber or
blackish or dark brown. Base chromosome number x=9 or 10.
A variable genus of 370-500 species from tropical, subtropical or warm temperate regions. The species
occupy a variety of habitats e.g. shade, open, mesic, or xeric. Several species are weedy including (P.
dichotomiflorum, P. capillare, P. maximum). Several species are valuable for livestock forage and include
switchgrass (P. virgatum), vine mesquite (P. obtusum), and kleingrass (P. coloratum).