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Avena
OATS

Higher Taxonomy
Family: Poaceae (Gramineae)View DescriptionDichotomous Key

Common Name: GRASS FAMILY
Habit: Annual to woody perennial herb; roots generally fibrous. Stem: generally round, hollow; nodes swollen, solid. Leaf: alternate, 2-ranked, generally linear, parallel-veined; 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; perianth vestigial; stamens generally 3; stigmas generally 2, generally plumose. Fruit: grain, sometimes achene- or utricle-like.
Genera In Family: 650--900 genera; +- 10550 species: worldwide; greatest economic importance of any family (wheat, rice, maize, millet, sorghum, sugar cane, forage crops, ornamental, weeds; thatching, weaving, building materials). Note: Generally wind-pollinated. Achnatherum, Ampelodesmos, Hesperostipa, Nassella, Piptatherum, Piptochaetium, Ptilagrostis moved to Stipa; Elytrigia, Leymus, Pascopyrum, Pseudoroegneria, Taeniatherum to Elymus; Hierochloe to Anthoxanthum; Lolium, Vulpia to Festuca; Lycurus to Muhlenbergia; Monanthochloe to Distichlis; Pleuraphis to Hilaria; Rhynchelytrum to Melinis. The following taxa (in genera not included here), recorded in California from historical collections or reported in literature, are extirpated, lacking vouchers, or not considered naturalized: Acrachne racemosa (Roth) Ohwi, Allolepis texana (Vasey) Soderstr. & H.F. Decker, Amphibromus nervosus (Hook. f.) Baill., Axonopus affinis Chase, Axonopus fissifolius (Raddi) Kuhlm., Coix lacryma-jobi L., Cutandia memphitica (Spreng.) K. Richt., Dinebra retroflexa (Vahl) Panz., Eremochloa ciliaris (L.) Merr., Eustachys distichophylla (Lag.) Nees, Gaudinia fragilis (L.) P. Beauv., Miscanthus sinensis Andersson, Neyraudia arundinacea (L.) Henrard, Phyllostachys aurea Rivière & C. Rivière, Phyllostachys bambusoides Siebold & Zuccarini, Rottboellia cochinchinensis (Lour.) Clayton, Schedonnardus paniculatus (Nutt.) Branner & Coville, Schizachyrium cirratum (Hack.) Wooton & Standl., Schizachyrium scoparium (Michx.) Nash, Themeda quadrivalvis (L.) Kuntze, Thysanolaena latifolia (Hornem.) Honda, Tribolium obliterum (Hemsl.) Renvoize, Zea mays L., Zizania palustris L. var. interior (Fassett) Dore, Zoysia japonica Steud. Paspalum pubiflorum E. Fourn., Paspalum quadrifarium Lam., are now reported for southern California (J Bot Res Inst Texas 4:761--770). See Glossary p. 30 for illustrations of general family characteristics.
eFlora Treatment Author: James P. Smith, Jr., except as noted
Scientific Editor: James P. Smith, Jr., J. Travis Columbus, Dieter H. Wilken.

Avena
Habit: 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.
Species In Genus: 29 species: temperate Europe, northern Africa, central Asia. Etymology: (Latin: oats) Note: 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.
eFlora Treatment Author: Bernard R. Baum, James P. Smith, Jr. & Dieter H. Wilken
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Citation for this treatment: Bernard R. Baum, James P. Smith, Jr. & Dieter H. Wilken 2016. Avena, in Jepson Flora Project (eds.) Jepson eFlora, http://ucjeps.berkeley.edu/cgi-bin/get_IJM.pl?tid=10991, accessed on December 07, 2016.

Citation for the whole project: Jepson Flora Project (eds.) 2016. Jepson eFlora, http://ucjeps.berkeley.edu/IJM.html, accessed on December 07, 2016.


Avena fatua
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© 2006 Steve Matson
Avena barbata
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© 2016 Keir Morse
Avena barbata
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© 2016 Keir Morse
Avena barbata
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© 2004 Carol W. Witham
Avena sativa
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© 2016 Keir Morse
Avena fatua
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© 2006 Steve Matson

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