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.

POA

BLUEGRASS

Robert J. Soreng

Annual, perennial herb, some ± dioecious
Stem 0.3–12 dm
Leaf: sheath open to closed (best observed on upper stem leaf); ligule thin, flexible; blade grooved above on both sides of midvein, flat, folded, or inrolled, generally smooth or scabrous on veins, generally prow-tipped
Inflorescence panicle-like; branches appressed to drooping
Spikelet generally compressed, breaking between florets; glumes 2, similar, generally < lowest lemma, awnless; florets generally 2–6; callus indistinct, often with obvious tuft of long cobwebby hairs; lemma generally keeled to base, of same texture as glumes, awnless, veins generally 5, ± converging near tip; palea well developed, keels generally scabrous; fertile anthers 0.2–4.5 mm; ovary glabrous
Species in genus: ± 500 species: temp and cool regions
Etymology: (Greek: ancient name)
Reference: [Soreng 1991 Syst Bot 16:507–528]
CA is center of diversity in North America. Spikelet features best observed on lowest florets of spikelet.

Introduced

P. trivialis L.

ROUGH BLUEGRASS

Perennial, short-lived, cespitose or with short stolons from a dense basal tuft, 3–10 dm
Leaf: sheath open generally 3/4, scabrous; ligule 3–7 mm, acute, scabrous; blade 1–5 mm wide, soft, generally flat, barely prow-tipped
Inflorescence 8–25 cm, open, lanceolate to ovate; branches ascending to spreading, densely scabrous, many-flowered from lower 1/2
Spikelet: lower glume 1-veined, ± sickle-shaped; callus sparsely long-cobwebby; lemma ± 2–3 mm, keel (rarely marginal veins) hairy near base
Flower: anthers 1.4–2 mm
Chromosomes: 2n=14
Ecology: Disturbed moist places
Elevation: 0–700 m.
Bioregional distribution: North Coast, Outer North Coast Ranges, probably elsewhere
Distribution outside California: to Alaska, e N.America; native to Europe
Fls spring and early summer.