Distribution: Reported from Whitman County in Washington; widely distributed throughout North America.
Habitat: Waste ground near fields.
Flowers: May-June
Origin: Introduced from the Mediterranean region
Growth Duration: Annual
Conservation Status: Not of concern
Pollination: Bees, flies, butterflies
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.
PNW Herbaria: Specimen records of Sinapis alba in the Consortium of Pacific Northwest Herbaria database
WA Flora Checklist: Sinapis alba checklist entry
OregonFlora: Sinapis alba information
E-Flora BC: Sinapis alba atlas page
CalPhotos: Sinapis alba photos