Description :

• Annual or perennial, tufted, stoloniferous, rhizomatous
• Leaf blade narrow-linear, expanded, folded or rolled; ligule a fringed membrane or a fringe of hairs
• Inflorescence a solitary, terminal, cylindrical to subglobose spike-like panicle, branches short or reduced to stumps, rarely axillary, then gathered into a leafy false panicle, or 2-4 spikelets enclosed in uppermost sheath ( P. clandestinum ); spikelets subtended by an involucre of filiform or slender, glabrous, scabrid or plumose, rarely solitary bristles, free to base, falling with spikelets at maturity (except in cultivated forms); spikelets solitary or in clusters of 2-5, outer often reduced, sessile or shortly pedicelled
• Spikelet narrowly lanceolate to oblong, dorsiventrally compressed to subterete; glumes unequal, awnless; lower glume up to half as long as spikelet, sometimes suppressed, thinly membranous, nerveless or 1-5-nerved; upper glume very small to as long as spikelet, 1-11-nerved
• Florets 2; lower floret male or sterile; lemma lanceolate or ovate-lanceolate, membranous, of variable length, acuminate, acute, 1-15-nerved, awnless or awned; palea well developed or reduced or 0; upper floret bisexual; lemma as long as or little shorter than spikelet, similar to firmer than glumes, membranous to thinly coriaceous, entire, 5-7-nerved, flat, thin margins covering ± half of palea, mucronate to awned; palea subequal and similar in texture to lemma, 2-nerved
• Lodicules small, 2 or 0
• Stamens 3; tips of anthers glabrous or minutely penicillate
• Ovary ellipsoid; style distinct or connate below
• Caryopsis oblong and dorsiventrally compressed to subglobose
• x = 9 (aneuploids, polyploidy)

Nomenclature:

• Pennisetum Rich.
  • Richard: 72 (1805)
  • Stapf: 430 (1899)
  • Stent: 273 (1924)
  • Chippindall: 439 (1955)
  • Launert: 146 (1970)
  • Burken: 161 (1977)
  • Clayton & Renvoize: 672 (1982)
  • Clayton & Renvoize: 303 (1986)
  • Clayton: 178 (1989)
  • Gibbs Russell et al.: 247 (1990)
  • Watson & Dallwitz: 703 (1994)
• Beckeropsis Fig. & De Not.
  • Figari & De Notaris: 49 (1853)

Distribution & Notes:

• Global : Species ± 80, cosmopolitan in tropical and warm regions
• Southern Africa : Species 14, widespread