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.

PUCCINELLIA

ALKALI GRASS

Jerrold I Davis

Annual, perennial herb; stolons and rhizomes generally 0
Stems decumbent to erect
Leaves basal and cauline; sheath open ± to base; ligule thinly membranous, acute to truncate, sometimes toothed
Inflorescence panicle-like; lower branches reflexed to erect; spikelets stalked
Spikelet bisexual; glumes < lowest floret, lower glume generally 1-veined, upper 3-veined; florets 2–9; lemma generally firm, back generally rounded, sometimes weakly keeled near tip, margin entire to scabrous-serrate near tip at 10X , glabrous to weakly puberulent at base, generally faintly 5-veined; awn 0; palea ± = lemma
Species in genus: 50 species: temp to arctic, North America, Eurasia
Etymology: (B. Puccinelli, Italy, 1808–1850)
Reference: [Davis 1983 Syst Bot 8:341–353]
Generally on wet saline or alkaline soils; some species difficult to separate without hand lens.