Plants annual. Culms 50-300 cm, erect, branching; nodes glabrous.
Sheaths glabrous or pubescent, with or without ciliate margins; ligules
2-5 mm; blades 15-100 cm long, 7-70 mm wide, flat, glabrous or pubescent.
Panicles terminal, 4-200 cm long, 2-70 mm wide, fully exerted from the
sheaths, erect; rachises terete, densely pubescent. Fascicles 33-160
per cm; fascicle axes 1-28 mm, persistent, with 1-9 spikelets; outer
bristles 44-131, 0.5-6 mm; inner bristles 6-19, 4-6 mm, plumose; primary
bristles 5.5-6.3, ciliate, sometimes noticeably longer than the other bristles.
Spikelets 3-7 mm; pedicels 0.6-1.8 mm; lower glumes absent
or to 1.5 mm, veinless; upper glumes 0.5-3.5 mm, 3-5-veined; lower florets
staminate or sterile; lower lemmas 1.5-6 mm, glabrous, 3-7-veined, margins
ciliate; lower paleas vestigial or fully
developed, margins ciliate; anthers 2.2-2.5 mm, penicillate; upper florets
coriaceous, shiny; upper lemmas 4.3-7 mm, 5-7(9)-veined, margins ciliate;
upper paleas 3.4-3.9 mm, pubescent, at least near the base, margins ciliate;
anthers 2-2.2 mm, penicillate. Caryopses 2-5.5 mm long, 1.6-3.2
mm wide, protruding from the lemma and palea at maturity. 2n = 14.
Pennisetum glaucum, a native of Asia, is cultivated in the United States
for grain, forage, and birdseed. It is the most drought tolerant of the tropical
cereal crops. Under favorable conditions, 10,000-30,000+ fascicles may be produced.
In the Flora region, it is used for soil stabilization, partly because
it seldom persists for more than 1-2 years.
Annual 3-13 dm, usually erect, often in large tufts; sheaths glabrous; blades loosely twisted, to 30 cm, 4-10 mm wide, scabrous above and with long papillose hairs near the throat, glabrous beneath; infl stiffly erect, cylindric, (3-)5-10(-15) cm, yellowish, the axis hispid; bristles 4-12 below each spikelet, 3-8 mm, antrorsely scabrous; spikelets 3-3.5 mm; first glume 3-veined, a third as long as the spikelet, the second 5-veined, half as long as the spikelet; sterile lemma about equaling the fertile one, clasping a broad hyaline palea of equal length, sometimes staminate; fertile lemma transversely strongly rugulose; 2n=36, 72. Cult. soil and waste places; native of Europe, now a cosmopolitan weed, and abundant throughout our range. (S. lutescens; S. pumila)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.