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.

MUHLENBERGIA

MUHLY

Paul M. Peterson

Annual, perennial herb, sometimes mat-like, often rhizomed
Stem decumbent to erect, ± clumped
Leaves basal and cauline; sheath open; ligule membranous, entire to irregularly toothed, sometimes with 1 large tooth on each side; blade flat to rolled
Inflorescence panicle-like, narrow to open; branches spreading to appressed
Spikelet: glumes subequal, generally 1-veined, short-pointed to awned, upper glume sometimes 3-veined; florets 1, sometimes 2, breaking above glumes; lemma short-pointed to awned, glabrous to hairy, 3-veined; palea < to = lemma
Fruit ± fusiform, reddish brown, generally falling with lemma and palea
Species in genus: ± 160 species: temp Am, s Asia
Etymology: (H.L.E. Muhlenberg, Pennsylvania botanist, 1753–1815)
Reference: [Reeder 1981 in Gould and Moran 1981 San Diego Soc Nat Hist Memoir 12:67–78]
Horticultural information: STBL.

Native

M. utilis (Torr.) Hitchc.

APAREJOGRASS

Perennial; rhizome scaly
Stem decumbent, often creeping, 0.5–3 dm
Leaf: ligule 0.3–0.8, truncate, decurrent to sheath; blade 1–3.5 cm, 0.6–1.2 mm wide, flat to ± rolled
Inflorescence 1–5 cm, 1–3 mm wide, narrow; branches short, appressed; axis generally visible between branches
Spikelet: glumes 0.5–1.5 mm, acute; lemma 1.5–2.5 mm, acute, glabrous; anther 1–1.2 mm, yellow to purple
Chromosomes: 2n=20
Ecology: Wet sites along streams, ponds
Elevation: 250–1000 m.
Bioregional distribution: Outer South Coast Ranges, South Coast, Western Transverse Ranges
Distribution outside California: to Texas, C.America