Burke: Avena fatua vs. Avena sativa

	Avena fatua	Avena sativa
	wild oat	oat
Habit	Annuals, the culms to 1 m. tall, hollow.	Glabrous annuals, the culms to 2 m. tall in some varieties, hollow.
Leaves	Sheaths open; ligules 3-6 mm. long, obtuse to acute, puberulent; blades 3-10 mm. broad, scabrous, often with a few long hairs.	Sheaths open; ligules 2-4 mm. long, puberulent, obtuse; blades 3-10 mm. broad, smooth or scabrous.
Flowers	Inflorescence a large, open panicle, the spikelets pendulous; spikelets usually 3-flowered, the rachilla readily disarticulating between the florets, strongly bearded; glumes membranous, the first 7-nerved, the second 9-nerved; lemmas densely bearded on the callus, the upper portion greenish, but the tip membranous and acutely bilobed for 1 mm.; first 2 florets with twisted, strongly-bent awns up to 4 cm. long; lodicules 2 mm. long.	Inflorescence a large, open panicle, the spikelets pendulous; spikelets usually 2-flowered, the rachilla firm, not readily disarticulating; glumes 20-25 mm. long, subequal, exceeding the florets; lemmas hardened, thickened, greenish, smooth to above midlength and prominently veined above, glabrous, entire at the tip, the callus usually naked; awn lacking on the second floret, attached about the middle of the first floret, nearly straight, up to 15 mm. long; lodicules linear, 1.8 mm. long.
Fruits	Utricle	Utricle

	Avena fatua	Avena sativa
Flowering time	May-September	June-August
Habitat	Fields, roadsides, wastelots, and other disturbed areas.	Fields, roadsides, wastelots, and other disturbed areas.
Distribution	Occurring on both sides of the Cascades crest in Washington; Alaska to California, east across North America to the Atlantic Coast. [WildflowerSearch map] [BONAP county map]	Occurring chiefly west of the Cascades crest in Washington; Alaska to California, east across North America to the Atlantic Coast. [WildflowerSearch map] [BONAP county map]
Origin	Introduced from Eurasia	Introduced from the Mediterranean region
Conservation status	Not of concern	Not of concern
Sibling taxa	A. barbata, A. sativa	A. barbata, A. fatua
Web links	Local floras: BC, CA, OR, WA Local Web sites: CalFlora, CalPhotos, Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search	Local floras: BC, CA, OR, WA Local Web sites: CalFlora, CalPhotos, Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Avena sativa

wild oat

oat

Habit

Annuals, the culms to 1 m. tall, hollow.

Glabrous annuals, the culms to 2 m. tall in some varieties, hollow.

Leaves

Sheaths open;

ligules 3-6 mm. long, obtuse to acute, puberulent;

blades 3-10 mm. broad, scabrous, often with a few long hairs.

Sheaths open;

ligules 2-4 mm. long, puberulent, obtuse;

blades 3-10 mm. broad, smooth or scabrous.

Flowers

Inflorescence a large, open panicle, the spikelets pendulous;

spikelets usually 3-flowered, the rachilla readily disarticulating between the florets, strongly bearded;

glumes membranous, the first 7-nerved, the second 9-nerved;

lemmas densely bearded on the callus, the upper portion greenish, but the tip membranous and acutely bilobed for 1 mm.; first 2 florets with twisted, strongly-bent awns up to 4 cm. long;

lodicules 2 mm. long.

Inflorescence a large, open panicle, the spikelets pendulous;

spikelets usually 2-flowered, the rachilla firm, not readily disarticulating;

glumes 20-25 mm. long, subequal, exceeding the florets;

lemmas hardened, thickened, greenish, smooth to above midlength and prominently veined above, glabrous, entire at the tip, the callus usually naked; awn lacking on the second floret, attached about the middle of the first floret, nearly straight, up to 15 mm. long;

lodicules linear, 1.8 mm. long.

Fruits

Utricle