Page author: David Giblin
Descurainia pinnata
western tansymustard

Distribution: Occurring chiefly east of the Cascades crest in Washington; British Columbia to California, east across North America to the Atlantic Coast.

Habitat: Weedy native of fairly dry, open ground.

Flowers: April-July

Origin: Native

Growth Duration: Annual

Conservation Status: Not of concern

Pollination: Bees, flies


Greenish to grayish annual, finely and sometimes glandular above, the usually freely-branched stem 1-7 dm. tall.


Leaves alternate, mainly cauline, broadly lanceolate to oblanceolate, the lower petiolate, 3-10 cm. long, bipinnate-pinnatifid to pinnate-pinnatifid, somewhat toothed, the segments linear or a little broader; upper leaves reduced, usually pinnatifid into linear segments.


Inflorescence of bractless racemes; pedicles 3-18 mm. long, spreading and often bent to ascending; sepals 4, 1-2 mm. long, spreading; petals 4, pale to bright yellow, 1.5-3.5 mm. long; stamens 6; style inconspicuous.


Siliques 4-20 mm. long and about 1.5 mm. broad, narrowly elliptic in outline, rounded at the tip; seeds in 2 series at mid-length.

Accepted Name:
Descurainia pinnata (Walter) Britton
Publication: Mem. Torrey Bot. Club. 5: 173. 1894.

Synonyms & Misapplications:
(none provided)
Additional Resources:

PNW Herbaria: Specimen records of Descurainia pinnata in the Consortium of Pacific Northwest Herbaria database.

WA Flora Checklist: Descurainia pinnata checklist entry.

OregonFlora: Descurainia pinnata information.

E-Flora BC: Descurainia pinnata atlas page.

CalPhotos: Descurainia pinnata photos.

USDA Plants: Descurainia pinnata information.

31 photographs:
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