TREATMENT FROM THE JEPSON MANUAL (1993) previous taxon | next taxon
Jepson Interchange (more information)
©Copyright 1993 by the Regents of the University of California
For up-to-date information about California vascular plants, visit the Jepson eFlora.

    THIS PAGE IS NO LONGER UPDATED
    AND IS MAINTAINED FOR ARCHIVAL PURPOSES ONLY
  • Up-to-date information about California vascular plants is available from the Jepson eFlora.

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.

AVENA

OATS

Dieter H. Wilken

Annual
Stems erect, 1–6, ± glabrous
Leaves basal and cauline; ligules 2–5 mm, membranous, rounded at tip; blade flat
Inflorescence panicle-like, open
Spikelets generally stalked, ± pendent; glumes subequal, generally > florets, membranous, 5–7-veined, generally glabrous; axis prolonged behind upper floret, vestigial floret at tip; florets 2–3, upper floret > lower, bisexual, breaking above glumes and between florets or not breaking; lemmas hard, glabrous to hairy below awn, awned at or slightly below middle, tip 2-forked, 5–7-veined, awn stiff, bent to straight, slightly to strongly coiled below bend; palea ± < lemma
Species in genus: ± 10–15 species: temp Eur, Asia. Cult for grain, hay
Etymology: (Latin: oats)

Introduced

A. sterilis L.


Stem 5–12 dm
Leaf: blade 4–8 mm wide, minutely scabrous
Spikelet: glumes 25–45 mm, 7–11-veined; lemmas 18–30 mm, stiff-hairy below awn, forks at tip ± 2 mm, awn 35–90 mm, bent, twisted and short-hairy below bend
Ecology: Disturbed sites
Elevation: 30–120 m.
Bioregional distribution: San Francisco Bay Area
Distribution outside California: native to s Europe
Hybridizes with A. fatua.

previous taxon | next taxon
bioregional map for AVENA%20sterilis being generated
 


Retrieve Jepson Interchange Index to Plant Names entry for Avena sterilis
Retrieve dichotomous key for Avena
Return to treatment index page
Glossary
University & Jepson Herbaria Home Page | Copyright © by the Regents of the University of California