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.

BOUTELOUA

GRAMA

J. Travis Columbus

Annual, perennial herb, generally cespitose
Stem solid, generally glabrous
Leaves generally basal; ligule generally < 1 mm, generally hairy; blade flat to inrolled, upper surface generally ± short-hairy, often ciliate near ligule, hairs long, bulbous-based
Inflorescence generally panicle-like; branches spike-like, 1 per node, persistent or deciduous in fruit; spikelets 2-rowed on 1 side of axis, overlapping
Spikelet sessile or short-stalked, ± cylindric to laterally compressed; glumes generally unequal, generally lanceolate, 1-veined, upper glume firmer than lower; axis (if inflorescence branch persistent) breaking between glumes and lower floret; florets generally 2–3, lower floret bisexual, > upper, upper florets generally vestigial, sterile; lemmas 3-veined, generally 3-awned, awns straight, scabrous; palea ± = lemma
Species in genus: ± 40 species: Am
Etymology: (Claudio (born 1774) and Esteban (born 1776) Boutelou, Spanish botanists, horticulturists)
Reference: [Gould 1979 Ann Missouri Bot Gard 66:348–416]
Many species important for forage.

Native

B. aristidoides (Kunth) Griseb. var. aristidoides

NEEDLE GRAMA

Annual
Stem decumbent to erect, 0.5–3.5 dm
Leaf: blade < 7 cm, < 2 mm wide
Inflorescence: branches 4–16, 8–25 mm, appressed to reflexed, deciduous in fruit; branch axis exceeding terminal spikelet node > 5 mm, base densely short-hairy; spikelets 1–4 per branch, generally appressed, falling with branch
Spikelet: upper glume 5–7 mm, glabrous or hairy, acute; florets (1)2; lower floret lemma ± = upper glume, glabrous or hairy, lobes 0, awns 0 or 2, < 1 mm; upper floret base hairy-tufted, lobes generally 0 between awn bases, awns 2–7 mm, generally unequal
Chromosomes: 2n=40
Ecology: Dry, open, sandy to rocky slopes, flats, washes, disturbed sites, scrub, woodland
Elevation: < 1800 m.
Bioregional distribution: e Peninsular Ranges, e&s Mojave Desert, Sonoran Desert
Distribution outside California: to Utah, Texas, s Mexico, S.America
Flowering time: Apr–Sep
Another var. in AZ, NM, n Mex
Horticultural information: STBL.