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Vascular Plants of California
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Avena fatua
WILD OAT


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.
Genus: AvenaView DescriptionDichotomous Key


Common Name: OATS
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.
Etymology: (Latin: oats) Note: Cultivated 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
Reference: Baum 2007 FNANM 24:734--739
Unabridged Reference: Baum 1977 Biosystematics Res Inst Monogr 14
Avena fatua L.
NATURALIZED
Stem: 3--16 dm, erect at maturity. Leaf: blade 10--45 cm, 4--15 mm wide, margins glabrous. Spikelet: 18--32 mm; breaking apart above glumes and between florets; glumes 18--32 mm, 9--11-veined; callus bearded; florets 2--3, lemma 14--20 mm, generally glabrous on back to soft-hairy in lower 1/3, tip 2-forked, forks < 1 mm, awn of lowest floret 25--40 mm, bent, twisted below bend. Chromosomes: 2n=42.
Ecology: Disturbed sites; Elevation: < 2400 m. Bioregional Distribution: CA-FP, MP, DMoj; Distribution Outside California: to Alaska, eastern Canada, most of United States; native to Eurasia. Flowering Time: Apr--Jun Note: Hybridizes with Avena sativa.
Jepson eFlora Author: Bernard R. Baum, James P. Smith, Jr. & Dieter H. Wilken
Reference: Baum 2007 FNANM 24:734--739
Index of California Plant Names (ICPN; linked via the Jepson Online Interchange)
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Botanical illustration including Avena fatua

botanical illustration including Avena fatua

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Citation for this treatment: Bernard R. Baum, James P. Smith, Jr. & Dieter H. Wilken 2012, Avena fatua, in Jepson Flora Project (eds.) Jepson eFlora, https://ucjeps.berkeley.edu/eflora/eflora_display.php?tid=15321, accessed on April 16, 2024.

Citation for the whole project: Jepson Flora Project (eds.) 2024, Jepson eFlora, https://ucjeps.berkeley.edu/eflora/, accessed on April 16, 2024.

Avena fatua
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©2008 Keir Morse
Avena fatua
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©2008 Thomas Stoughton
Avena fatua
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©2006 Steve Matson
Avena fatua
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©2006 Steve Matson
Avena fatua
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©2006 Steve Matson

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Geographic subdivisions for Avena fatua:
CA-FP, MP, DMoj
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map of distribution 1
(Note: any qualifiers in the taxon distribution description, such as 'northern', 'southern', 'adjacent' etc., are not reflected in the map above, and in some cases indication of a taxon in a subdivision is based on a single collection or author-verified occurence).





 

Data provided by the participants of the  Consortium of California Herbaria.
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Blue markers indicate specimens that map to one of the expected Jepson geographic subdivisions (see left map). Purple markers indicate specimens collected from a garden, greenhouse, or other non-wild location.
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CCH collections by month

Duplicates counted once; synonyms included.
Species do not include records of infraspecific taxa, if there are more than 1 infraspecific taxon in CA.
Blue line denotes eFlora flowering time (fruiting time in some monocot genera).