Family: Poaceae Images not available |
J.K Wipff Plants annual or perennial; habit various. Culms 3-800 cm, not woody, sometimes branching above the base; internodes solid or hollow. Ligulesmembranous and ciliate, or of hairs, rarely completely membranous; blades sometimes pseudopetiolate. Inflorescences spicate panicles with highly reduced branches termed fascicles; panicles 1-many per plant, terminal on the culms or on both the culms and the secondary branches, or terminal and axillary, or only axillary, usually completely exposed at maturity; rachises usually terete, with (1)5-many fascicles; fascicle axes 0.2-7.5(28) mm, with (1)3-130+ bristles and 1-12 spikelets. Bristles free or fused at the base, disarticulating with the spikelets at maturity; of 3 kinds, outer, inner, and primary, in some species with all 3 kinds present below each spikelet, in others 1 or more kinds missing from some or all of the spikelets; outer (lower) bristles antrorsely scabrous, terete; inner (upper) bristles antrorsely scabrous or long-ciliate, usually flatter and wider than the outer bristles; primary(terminal) bristles located immediately below the spikelets, solitary, antrorsely scabrous or long-ciliate, often longer than the other bristles associated with the spikelet; disarticulation usually at the base of the fascicles, sometimes also beneath the upper florets. Spikelets with 2 florets; lower glumesabsent or present, 0-5-veined; upper glumes longer, 0-11-veined; lower florets sterile or staminate; lower lemmas usually as long as the spikelets, membranous, 3-15-veined, margins usually glabrous; lower paleas present or absent; upper lemmas membranous to coriaceous, 5-12-veined; upper paleas shorter than the lemmas but similar in texture; lodicules 0 or 2, glabrous; anthers 3, if present. x = 5, 7, 8, 9 (usually 9). Name from the Latin penna, feather, and seta, bristle, an allusion to the plumose bristles of some species. SELECTED REFERENCES Brunken, J.N.1977. A systematic study of Pennisetum sect. Pennisetum (Gramineae). Amer. J. Bot. 64:161-176; Brunken, J.N. 1979. Morphometric variation and the classification of Pennisetum section Brevivalvula (Gramineae) in tropical Africa. Bot. J. Linn. Soc. 79:51-64; Chase, A. 1921. The North American species of Pennisetum. Contr. U.S. Natl. Herb. 224:209-234; Goebel, K.I.1882. Beitrage zur Entwickelungsgeschichte einiger Inflorescenzen. Jahrb. Wiss. Bot. 14:1-39; Hignight, K.W., E.C. Basha, and M.A. Hussey. 1991. Cytological and morphological diversity of native apomictic buffelgrass, Pennisetum ciliare (L.) Link. Bot. Gaz. 152:214-218; Schmelzer, G.H. 1997. Review of Pennisetum section Brevivalvula (Poaceae). Euphytica 97:1-20; Sohns, E.R. 1955. Cenchrus and Pennisetum: Fascicle morphology. J. Wash. Acad. Sci. 45:135-143; Wipff, J.K. 1995. A biosystematic study of selected facultative apomictic species of Pennisetum (Poaceae: Paniceae) and their hybrids. Ph.D. dissertation, Texas A&M University, College Station, Texas, U.S.A. 183 pp.; Wipff, J.K. 2001. Nomenclatural changes in Pennisetum(Poaceae: Paniceae). Sida:19:523-530. |