Page authors: Don Knoke, David Giblin
Sinapis alba
white mustard

Distribution: Occurring east of the Cascades crest in eastern Washington; Yukon Territory to California, east across most of North America to the Atlantic Coast.

Habitat: Fields, roadsides, wastelots, and other disturbed areas.

Flowers: May-June

Origin: Introduced from the Mediterranean region

Growth Duration: Annual

Conservation Status: Not of concern


Annual, nearly glabrous, or with stiff, pungent hairs, the stems freely-branched, 2-10 dm. tall.


Leaves alternate, pinnate to pinnatifid into 3-7 wavy-toothed segments, 8-20 cm. long and 5-15 cm. broad, reduced above and becoming wavy-lobed.


Inflorescence of open, bractless racemes; pedicles 5-10 mm. long, spreading; sepals 4, 4-5 mm. long, slightly gibbous-based; petals 4, yellow, clawed, 10-15 mm. long; stamens 6.


Siliques spreading, curved, 3-4 cm. long and 3.5-4.5 mm. broad, 3-nerved, coarsely stiff-hairy, with a strongly flattened beak, somewhat shorter to twice as long as the valves; seeds in 1 series.

Accepted Name:
Sinapis alba L.
Publication: Sp. Pl. 2: 668. 1753.

Synonyms & Misapplications:
Brassica hirta Moench [HC]
Additional Resources:

PNW Herbaria: Specimen records of Sinapis alba in the Consortium of Pacific Northwest Herbaria database.

WA Flora Checklist: Sinapis alba checklist entry.

E-Flora BC: Sinapis alba atlas page.

CalPhotos: Sinapis alba photos.

USDA Plants: Sinapis alba information.

6 photographs:
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