Plants perennial; rhizomatous, rhizomes short, knotty. Culms 30-120
cm; nodes glabrous. Sheaths glabrous; ligules shorter than
1 mm, of hairs; blades to 25 cm long, 2-8 mm wide, flat, scabrous above.
Panicles 3-8(10) cm, of uniform width throughout their length, densely
spikelike; rachises scabro-hispid; bristles 4-12, 2-12 mm, antrorsely
barbed, yellow to purple. Spikelets 2-2.8 mm, elliptical and turgid. Lower
glumes about 1/3 as long as the spikelets, 3-veined; upper glumes 1/2-2/3
as long as the spikelets, 5-veined; lower florets often staminate; lower
lemmas occasionally indurate and faintly transversely rugose; lower paleas
equaling the lower lemmas; upper lemmas distinctly transversely rugose,
often purple-tipped. 2n = 36, 72.
Setaria parviflora is a common, native species of moist ground. It is most
frequent along the Atlantic and Gulf coasts, but it also grows from the Central
Valley of California east through the central United States and southward through
Mexico to Central America, as well as in the West Indies. The plant from Oregon
was found on a ballast dump; the species is not established in that state.
Setaria parviflora is the most morphologically diverse and widely distributed
of the indigenous perennial species of Setaria.
Plants annual or perennial; cespitose from a hard, knotty base. Culms
30-200 cm, erect, branching; nodes glabrous. Sheaths glabrous, margins
ciliate; ligules 1.5-2.7 mm; blades 15-55 cm long, 4-18 mm wide,
flat, glabrous or pubescent. Panicles terminal, 10-25 cm long, 15-30 mm
wide, fully exerted from the sheaths, erect to drooping, white, yellow, light
brown, or pink to deep purple; rachises terete, scabrous. Fascicles
33-45 per cm, disarticulating at maturity; fascicles axes 0.2-0.5 mm, with
1 spikelet; outer bristles 13-30, 1.3-5 mm, scabrous; inner bristles
6-14, 4.3-11.5 mm, long ciliate; primary bristles 14-25 mm, long-ciliate,
noticeably longer than the other bristles. Spikelets 3-4.5 mm, sessile;
lower glumes absent or to 2 mm, veinless; upper glumes 3-4.5 mm,
glabrous, 5-7-veined, 3-lobed; lower florets sterile or staminate; lower
lemmas 3-3.9 mm, 5-7-veined, apices lobed; lower paleas 2.9-3.7 mm;
anthers absent or 1.7-2 mm; upper florets disarticulating at maturity;
upper lemmas 1.7-3 mm, coriaceous, shiny, 5-veined, apices ciliate; anthers
1.3-2.1 mm. Caryopses about 1.7 mm, concealed by the lemma and palea at
maturity. 2n = 18, 36, 45, 48, 52, 53, 54, 56, 78.
Pennisetum polystachion is a polymorphic, weedy African species that has
become established in the tropics and subtropics, including Florida. The U.S.
Department of Agriculture considers it a noxious weed. Only Pennisetum polystachion
subsp. setosum (Sw.) Brunken has
been found in the Flora region. It differs from P. polystachion
(L.) Schult. subsp. polystachion
as indicated in the key below.
Perennial 3-12 dm from short, knotty rhizomes; sheaths glabrous; blades flat, to 25 cm, 2-8 mm wide, scabrous above and sometimes long-hairy at the throat; infl dense, cylindric, 3-10 cm, green or tawny, its axis scabrous-hispid; bristles 4-12 below each spikelet, 2-12 mm, antrorsely barbed; spikelets 2-2.8 mm; first glume 3-veined, a third as long as the spikelet, the second 5- veined, half to two-thirds as long as the spikelet; sterile lemma equaling the fertile one, clasping a broad palea of equal length, often staminate; fertile lemma transversely rugulose; 2n=36, 72. Moist ground, gardens, salt- marshes, and waste places; tropical N. Amer., n. to Calif., Tex., Kans., Io., Ill., W.Va., and Mass. (S. geniculata)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.