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barbed oat, slender oat, slender wild oat, slim oat

common wild oats, flaxgrass, folle avoine, oatgrass, wheat oats, wild oat

Habit Plants annual. Plants annual.
Culms

60-80 (150) cm, initially prostrate, usually becoming erect.

8-160 cm, prostrate to erect when young, becoming erect at maturity.

Sheaths

of the basal leaves pilose, upper sheaths usually glabrous;

ligules 1-6 mm, obtuse;

blades 6-30 cm long, 2-20 mm wide, glabrous or pilose.

of the basal leaves with scattered hairs, upper sheaths glabrous;

ligules 4-6 mm, acute;

blades 10-45 cm long, 3-15 mm wide, scabridulous.

Panicles

15-35.5 (50) cm long, 6-12 cm wide, erect or nodding.

7-40 cm long, 5-20 cm wide, nodding.

Spikelets

21-30 mm, with 2-3 florets;

disarticulation beneath each floret;

disarticulation scars elliptic to triangular.

18-32 mm, with 2(3) florets;

disarticulation beneath each floret;

disarticulation scars of all florets round to ovate or triangular.

Glumes

subequal, 15-30 mm, 7-9-veined;

calluses bearded, hairs 2-3 mm;

lemmas 15-26 mm, densely strigose below midlength, apices acute, biaristate, 2 veins extending 2-4 mm beyond the apices, awns 30-45 mm, arising about midlength, geniculate;

lodicules narrowly triangular, without lobes on the wings;

anthers 2.5-4 mm.

subequal, 18-32 mm, 9-11-veined;

calluses bearded, hairs to 1/4 the length of the lemmas;

lemmas 14-22 mm, usually densely strigose below midlength, sometimes sparsely strigose or glabrous, veins not extending beyond the apices, apices usually bifid, teeth 0.3-1.5 mm, awns 23-42 mm, arising in the middle 1/3 of the lemmas;

lodicules without lobes on the wings;

anthers about 3 mm.

2n

= 28.

= 42.

Avena barbata

Avena fatua

Distribution
from FNA
AZ; CA; MA; MT; NM; NV; OR; WA; HI
[WildflowerSearch map]
[BONAP county map]
from FNA
AK; AL; AZ; CA; CO; CT; DE; FL; IA; ID; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; MT; ND; NE; NH; NJ; NM; NV; NY; OH; OK; OR; PA; SD; TN; TX; UT; VA; VT; WA; WI; WV; WY; HI; AB; BC; LB; MB; NB; NS; NT; ON; PE; QC; SK
[WildflowerSearch map]
[BONAP county map]
Discussion

Avena barbata is native to the Mediterranean region and central Asia. It has become naturalized in western North America, particularly California, displacing native grasses. It was collected once in Vancouver, British Columbia, but should be considered a waif there.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Avena fatua is native to Europe and central Asia. It is known as a weed in most temperate regions of the world; it is considered a noxious weed in some parts of Canada and the United States.

Avena fatua is sometimes confused with A. occidentalis, but differs in having shorter, wider spikelets, fewer florets, and a distal floret which does not have a heart-shaped disarticulation scar. Hybrids between A. fatua and A. sativa are common in plantings of cultivated oats. The hybrids resemble A. sativa, but differ in having the fatua-type lodicule; some also have a weak awn on the first lemma. They are easily confused with fatuoid forms of A. sativa.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 24, p. 735. FNA vol. 24, p. 735.
Parent taxa Poaceae > subfam. Pooideae > tribe Poeae > Avena Poaceae > subfam. Pooideae > tribe Poeae > Avena
Sibling taxa
A. fatua, A. hybrida, A. occidentalis, A. sativa, A. sterilis
A. barbata, A. hybrida, A. occidentalis, A. sativa, A. sterilis
Synonyms A. fatua var. glahrescens, A. fatua var. glabrata
Name authority Pott ex Link L.
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