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.

DESCHAMPSIA

HAIRGRASS

Dieter H. Wilken and Elizabeth Painter

Annual, perennial herb
Stems erect, solitary to densely clumped
Leaves basal to cauline; ligule narrow, decurrent to sheath, glabrous to minutely hairy; blades flat to inrolled
Inflorescence panicle- to spike-like, open to narrow
Spikelet: glumes and lemmas shiny; glumes equal to ± subequal, > lower floret; axis prolonged beyond upper floret, bristly (sometimes with vestigial floret at tip); florets 1–3, bisexual, breaking above glumes and between florets; callus soft-hairy; lemmas rounded, 2–4-toothed at truncate tip, faintly 3–7-veined, awned at or below middle, awn straight to bent; palea ± = lemma
Species in genus: 30–40 species: temp Am, Eurasia, New Zealand, Antarctica
Etymology: (J. L-Deslongchamps, France, born 1774)

Native

D. elongata (Hook.) Munro

SLENDER HAIRGRASS

Perennial
Stems densely clumped, 1–7 dm
Leaves generally basal, tufted, glabrous; ligule 2–8 mm, acute to acuminate, entire; blades 4–8 cm, ± 1 mm wide, flat to inrolled
Inflorescence narrow; branches spike-like, ascending
Spikelet: glumes and lemmas green to tan, tips sometimes purplish; glumes 3–5 mm, ± subequal, narrow-lanceolate, acute to acuminate, 3-veined; florets generally 2; callus hairs ± 1/2 lemma length; lemmas 2–3 mm, 2–4-toothed at tip, faintly 5-veined, awned near middle, awn 1–5 mm, generally straight
Chromosomes: 2n=26
Ecology: Wet sites, meadows, lakeshores, shaded slopes
Elevation: 100–3100 m.
Bioregional distribution: California Floristic Province, Great Basin Floristic Province
Distribution outside California: to Alaska, Wyoming, Baja California, S.America
Flowering time: May–Aug
Horticultural information: IRR or WET: 1, 2, 3, 4, 5, 6, 17 &part SHD: 7, 8, 9, 14, 15, 16, 18, 19, 20, 21, 22, 23, 24.