TREATMENT FROM THE JEPSON MANUAL	previous taxon | next taxon Jepson Interchange (more information)
	©Copyright 1993 by the Regents of the University of California Print edition is available from the University of California Press

	The second edition of The Jepson Manual (2012) is available from the University of California Press
	See also the Jepson eFlora, which parallels the Second Edition

POACEAE

GRASS FAMILY

James P. Smith, Jr., except as specified

Annual to bamboo-like; roots generally fibrous
Stem generally round, hollow; nodes swollen, solid
Leaves alternate, 2-ranked, generally linear; sheath generally open; ligule membranous or hairy, at blade base
Inflorescence various (of generally many spikelets)
Spikelet: glumes generally 2; florets (lemma, palea, flower) 1–many; lemma generally membranous, sometimes glume-like; palea generally ± transparent, ± enclosed by lemma
Flower generally bisexual, minute; stamens generally 3; stigmas generally 2, generally plumose
Fruit: achene-like grain
Genera in family: 650–900 genera; ± 10,000 species: worldwide; greatest economic importance of any family (wheat, rice, maize, millet, sorghum, sugar cane, forage crops, ornamental, weeds; thatching, weaving, building materials). [Hitchcock 1951 Manual grasses US, USDA Misc Publ 200; Clayton & Renvoise 1986 Kew Bull Add Series 13] See Glossary p. 26 for illustrations of general family characteristics. Generally wind-pollinated.

PENNISETUM

Robert Webster

Annual, perennial herb
Stems prostrate to erect and tufted; internode spongy inside, sometimes hollow
Leaves basal and cauline; sheath generally glabrous; ligule short-hairy or membranous, ciliate
Inflorescence generally panicle-like, dense, ± cylindric (raceme-like, spikelets few in P. clandestinum), spikelets many, short-stalked to sessile, clustered, generally 1–4 per cluster, subtended by 5–50 flexible bristles; spikelet cluster and bristles generally falling as 1 unit
Spikelet compressed; glumes 1–2, lower glume < upper or 0, upper ± = spikelet; florets 2, lower floret generally sterile, lemma like glumes, upper floret fertile, lemma firm, ± thick or hard, smooth or scabrous, generally dull, margin flat to inrolled, tip blunt
Species in genus: ± 80 species: warm temp, tropical Eurasia, Africa
Etymology: (Latin: feather bristle)
Some species cultivated for ornamental, food.

Introduced

P. villosum R. Br.

Perennial, cespitose
Stem erect, 1.6–7.5 dm
Leaf: sheath 4–10 cm, glabrous; ligule ± 1–1.5 mm; blade 5–40 cm, 2–4.5 mm wide, upper surface glabrous to hairy
Inflorescence 4–8 cm; 1° branches (including bristles) 3–5 cm, glabrous; bristles subtending cluster 30–50
Spikelet 9–11 mm, ± 1.5 mm wide, lanceolate, green to white; lower glume < 1 mm, veins not visible; upper glume ± 0.5 X spikelet length; lower floret sterile or staminate, lemma 7–9-veined, tip acuminate, palea ± = lemma or 0; upper floret ± = to slightly > lower floret
Ecology: Waste places, urban roadsides
Elevation: < 100 m.
Bioregional distribution: Southwestern California, Sonoran Desert, expected elsewhere
Distribution outside California: to Texas; native to Africa
Flowering time: Jun–Aug