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. richardsonis (Trin.) Rydb.

MAT MUHLY

Perennial; rhizome scaly, matted
Stem decumbent to erect, 0.5–4 dm; lower nodes often swollen or knot-like
Leaf: ligule 1–2.5 mm, acute to truncate, decurrent to sheath; blade 1–5 cm, 1–2 mm wide, flat to ± rolled
Inflorescence 1–12 cm, 1–4 mm wide, cylindric, narrow; axis generally obscured by appressed branches
Spikelet: glumes 0.8–1.8 mm, acute to ± short-awned; lemma 2–3 mm, glabrous, ± scabrous at tip, ± short-awned, awn < 0.5 mm; anther 1.2–1.5, yellow to purple
Chromosomes: 2n=40
Ecology: Open sites, ± moist meadows, talus slopes, along streams
Elevation: 1220–3670 m.
Bioregional distribution: Klamath Ranges, High Cascade Range, High Sierra Nevada, Outer South Coast Ranges, Transverse Ranges, San Jacinto Mountains, Great Basin Floristic Province, Desert Mountains
Distribution outside California: to Canada, ne US, Mexico
Flowering time: Jun–Aug
Horticultural information: IRR, SUN: 1, 2, 3, 6, 11, 14, 15, 16, 18, 21; GRCVR.