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.

ELYMUS

Mary E. Barkworth

Perennial, sometimes from rhizomes
Stem generally bent at base or erect, generally tufted
Leaf: sheath appendaged, appendages sometimes small, fragile; ligule membranous, truncate to obtuse; blades flat, folded, or rolled
Inflorescence spike-like, open to dense; axis generally not breaking apart in fruit; spikelets ± 2-ranked or not, 1–4 per node, generally ascending
Spikelet: glumes lanceolate to awl-like, sometimes 0, awned from tip or not; florets 1–7; lemma generally > glumes, generally rounded, tip acute to awned, awn straight or curved outward; anthers 1–6 mm
Species in genus: 150 species: temp worldwide
Etymology: (Greek: ancient name for millet)
Reference: [Barkworth & Dewey 1985 Amer J Bot 72:767–776; Wilson 1963 Brittonia 15:303–323]
See Agropyron, Elytrigia, Leymus, Pseudoroegneria for species sometimes treated here. Some species hybridize; hybrids with Hordeum, Leymus, Pseudoroegneria also occur.

Native

E. trachycaulus (Link) Shinners

SLENDER WHEATGRASS

Stem 3–15 dm
Leaf: sheath glabrous to hairy, appendages < 1 mm; blade 2–8 mm wide, generally flat
Inflorescence 4–25 cm, not breaking apart with age; internodes 4–15 mm; spikelet 1 per node
Spikelet 10–20 mm; glumes 6–12 mm, acute to short-awned; lemma 6–13 mm, glabrous to hairy, awn 1–30 mm; anthers 1–2.5 mm
Chromosomes: 2n=28
Ecology: Dry to moist, open areas, forest, woodland
Elevation: < 3400 m.
Bioregional distribution: California (except Great Central Valley)
Distribution outside California: to Alaska, e US
Hybrids with Hordeum jubatum have been called E. macounii Vasey.

Native

subsp. subsecundus (Link) Gould

Spikelet: lemma awns 8–30 mm
Chromosomes: 2n=28
Ecology: Habitat of sp.
Elevation: 1000–3400 m.
Bioregional distribution: Sierra Nevada, Modoc Plateau
Distribution outside California: to Rocky Mtns
Synonyms: Agropyron s. (Link) Hitchc