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.


Dieter H. Wilken

Stems erect, solitary to tufted, generally glabrous
Leaves basal and cauline; ligule membranous, acute to toothed at tip; blade flat to rolled, generally ridged
Inflorescence panicle-like; branches spike-like, minutely scabrous
Spikelet: glumes subequal, > floret, membranous, lower 1-veined, upper 1–3-veined; floret 1, bisexual, breaking above glumes; lemma rounded on back, membranous, short bristly at base, minutely scabrous and awned near tip, obscurely 3–5-veined, awn straight, flexible; palea ± = lemma
Species in genus: ± 3 species: temp Eur, Asia. Cult for revegetation
Etymology: (Greek: not maimed, alluding to occasional presence of vestigial florets)


A. interrupta (L.) P. Beauv.

Stems generally < 3, 1–6 dm, sometimes tufted
Leaf: ligule 1–4 mm; blade 1–3 mm wide, minutely scabrous above
Inflorescence 5–15 cm; branches ascending; glumes 1.5–3 mm; lemma 1.5–2 mm, minutely scabrous at tip, awn 5–8 mm
Chromosomes: 2n=14, 28
Ecology: Disturbed sites
Elevation: 1220–1700 m.
Bioregional distribution: Modoc Plateau (w of Alturas, Modoc Co.), Desert Mountains (Furnace Creek, e Inyo Co.)
Distribution outside California: reported elsewhere in w US; native to Europe, Asia

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