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)
Reference: [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. elymoides (Raf.) Swezey

SQUIRRELTAIL

Stem 1–6.5 dm
Leaf: sheath glabrous to long-hairy, appendages < 1 mm; blade 1–6 mm wide, flat, folded, or rolled
Inflorescence 2.5–15 cm (except awns), breaking apart with age; internodes 3–10 mm; spikelets generally 2 per node
Spikelet 12–20 mm; glumes 35–85 mm, awn-like, base narrow, thick, generally spreading, sometimes with 1–2 short awns at base; lemma awn 30–90 mm, spreading; anthers ± 2 mm
Chromosomes: 2n=28
Ecology: Dry, open areas
Elevation: 600–4200 m.
Bioregional distribution: Klamath Ranges, Cascade Range, Sierra Nevada, San Francisco Bay Area, Transverse Ranges, Peninsular Ranges, Great Basin Floristic Province, Desert
Distribution outside California: to Washington, Great Plains, Texas, n Mexico
Synonyms: Sitanion hystrix (Nutt.) J.G. Sm
Hybrids with E. trachycaulus have been called E. macounii Vasey or (from c SNH, MP), E. saundersii Vasey [ Agropyron s. (Vasey) Hitchc.] Hybrids with E. glaucus have been called E. X hansenii Scribner [ Sitanion h. (Scribner) J.G. Sm.] Hybrids with Pseudoroegneria spicata have been called Agropyron saxicola (Scribner & J.G. Sm.) Piper. (see also E. multisetus ).

Native

subsp. elymoides

Inflorescence: spikelets generally 2 per node
Spikelet: some glumes divided, awns 2, 35–85 mm; lowest floret generally sterile, glume-like, fertile florets 1+; lemma awn 25–75 mm
Chromosomes: 2n=28
Ecology: Habitat of sp.
Elevation: 800–4000 m.
Bioregional distribution: San Francisco Bay Area, Transverse Ranges, San Jacinto Mountains, Great Basin Floristic Province, Desert
Distribution outside California: to Washington, Wyoming, Colorado
Flowering time: Jul–Aug
Synonyms: Sitanion hystrix (Nutt.) J.G. Sm. var. h
Horticultural information: SUN, DRN: 1, 2, 3, 7, 8, 9, 10, 11, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24.