Pennisetum

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).