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Key to families | Table of families and genera

Specimen numbers are hyperlinked to records in the Consortium of California Herbaria data view where possible. Taxa are hyperlinked to entries in the Jepson Interchange via the "[Online Interchange]" link.

 

AVENA OATS

Bernard R. Baum, James P. Smith, Jr. & Dieter H. Wilken


Annual. Stem: erect, 1–6, ± glabrous. Leaf: basal and cauline; ligule 2–5 mm, membranous, rounded at tip; blade flat. Inflorescence: panicle-like, open. Spikelet: 15–50 mm, laterally compressed, generally stalked, ± pendent; glumes unequal or ± equal, generally > florets, membranous, 3–11-veined, generally glabrous; axis occasionally prolonged behind upper floret, vestigial floret at tip; florets (1)2–6(8), 2+ bisexual, reduced florets distal to proximal ones, breaking above glumes and between florets or not; lemma hard, glabrous to hairy below awn, awned at or slightly below middle, 5–9-veined, tip 2-forked, forks ± tooth-like, awn stiff, generally bent, slightly to often strongly coiled below bend; palea ± < lemma; anthers 3. Fruit: cylindric, longitudinally grooved, pubescent.
29 species: temperate Europe, northern Africa, central Asia. (Latin: oats) [Baum 2007 FNANM 24:734–739] Cult for grain, hay. California records of Avena strigosa Schreb. are based on misidentifications of Avena barbata. California records of Avena occidentalis Durieu, are based on a misidentification of Avena fatua.
Unabridged references: [Baum 1977 Biosystematics Res Inst Monogr 14]

Key to Avena

1. Callus glabrous; florets remaining attached at maturity; lemma glabrous or nearly so, awn of lower floret generally 0(15) mm ..... A. sativa

1' Callus bearded; florets falling singly or as a unit at maturity; lemma densely strigose or soft hairy, especially below, awned

2. Lemma bristle-tipped, teeth 2–6 mm ..... A. barbata

2' Lemma tip ragged or 2-forked, teeth <= 1.5 mm

3. Florets falling separately from glumes; awn of lowest floret 25–40 mm; leaf margin glabrous ..... A. fatua

3' Florets falling from glumes as a unit; awn of lowest floret 35–90 mm; leaf margin sparsely hairy ..... A. sterilis

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Citation for an individual treatment: [Author of taxon treatment] [year]. [Taxon name] in Jepson Flora Project (eds.) Jepson eFlora, [URL for treatment]. Accessed on [month, day, year].
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