Jepson Flora Project: Jepson Interchange    

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Jepson Interchange (more information)
©Copyright 1993 by the Regents of the University of California

  • Up-to-date information about California vascular plants is available from the Jepson eFlora.



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.


Mary E. Barkworth

Stem generally unbranched
Inflorescence panicle-like; branches generally widely spreading
Spikelet: glumes tapered from near base to tip, tip narrowly acute, generally reddish; axis breaking above glumes; floret 1, generally round in X -section; callus 0.5–4 mm, generally sharp; lemma papillate or minutely tubercled at tip, sometimes hairy, margins strongly overlapping at maturity, tip neck-like, ciliate, generally pale colored; palea < 1/3 lemma length, glabrous, veins 0; anthers ciliate, often of 2 lengths
Species in genus: ± 80 species: Am
Etymology: (Latin: nassa, a basket with a narrow neck)
Reference: [Barkworth 1990 Taxon 39:597–614]
Segregated from Stipa ; see also Achnatherum, Hesperostipa.


N. formicarum (Delile) Barkworth

Stem 4–8 dm
Leaf: blade 1–2.5 mm wide
Inflorescence 20–25 cm
Spikelet: glumes 10–11 mm, ± equal; floret 5.5–7 mm; lemma hairy on lower third of midvein and marginal veins, neck 1–1.3 mm, conspicuous, white, awn 30–40 mm, distal segment straight
Ecology: Open, disturbed areas, roadsides, fields
Elevation: < 200 m.
Bioregional distribution: s Outer North Coast Ranges (Sonoma Co.), s Sacramento Valley, n San Francisco Bay Area
Distribution outside California: native to S.America
Synonyms: Stipa f. Delile

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