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    THIS PAGE IS NO LONGER UPDATED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.

ARRHENATHERUM

Dieter H. Wilken

Perennial
Stems erect
Leaves basal and cauline; ligule membranous, obtuse, minutely soft hairy; blade flat, soft hairy
Inflorescence panicle-like, narrow
Spikelet: glumes unequal, keeled, acute, lower 1-veined, upper 3-veined; florets 2, lower > upper, lower generally staminate, upper bisexual, breaking above glumes, falling as 1 unit; callus hairy; lemmas keeled, 5–7-veined, lemma of lower floret awned below middle, awn bent, stiff, upper lemma awnless or awned at tip, awn straight; palea < lemma
Species in genus: 6 species: temp Eur, Asia
Etymology: (Greek: masculine awn, referring to awned staminate floret)

Introduced

A. elatius (L.) J. Presl & C. Presl


Stem ascending to erect, 7–15 dm, sometimes bulbous at base
Leaf: ligule 1–3 mm, obtuse, minutely ciliate; blade 3–8 mm wide, flat, glabrous to minutely scabrous
Inflorescence 9–25 cm
Spikelet subsessile to stalked; lower glume 4–7 mm, upper 7–10 mm, glume margins translucent, keel soft-hairy; lemmas 6–9 mm, awn of lower lemma 10–17 mm, awn of upper < 4 mm (sometimes 0); palea translucent
Chromosomes: 2n=14,28, 42
Ecology: Disturbed and open sites
Elevation: 30–1800 m.
Bioregional distribution: Northwestern California, Cascade Range, n&c Sierra Nevada Foothills, c High Sierra Nevada, Central Coast, San Francisco Bay Area
Distribution outside California: to British Columbia, w US; native to temperate Europe
Cult for stabilizing bare soil. Plants with stems swollen at base have been called subsp. bulbosum (Willd.) Schuebler & Martens.

previous taxon | next taxon
bioregional map for ARRHENATHERUM%20elatius being generated
 


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