Distribution: Distributed throughout Washington but more common east of the Cascades; occurring throughout North America.
Habitat: Shrub-steppe, grasslands, and waste ground, especially following rangeland fires.
Flowers: May-September
Origin: Introduced from Eurasia
Conservation Status: Not of concern
Annual herb, the erect, freely-branching stems 3-15 dm. tall, glabrous above and with a few stiff hairs below.
Leaves alternate, broadly lanceolate or oblong to oblanceolate, up to 1.5 dm. long, petiolate, the lower ones pinnatifid, the segments often pointing backward, becoming pinnatifid with linear segments above.
Inflorescence of bractless racemes; pedicles stout, spreading, 4-10 mm. long; sepals 4, somewhat spreading, 4 mm. long; petals 4, pale yellowish, clawed, 6-8 mm. long; stamens 6; style lacking, stigma 2-lobed.
Siliques linear, terete, 5-10 cm. long, slightly broader than the pedicles, spreading and rigid; valves with a prominent mid-nerve and 2 evident lateral nerves; seeds in 1 series.
Publication: Sp. Pl. 2: 659. 1753. 1753.
PNW Herbaria: Specimen records of Sisymbrium altissimum in the Consortium of Pacific Northwest Herbaria database.
WA Flora Checklist: Sisymbrium altissimum checklist entry.
E-Flora BC: Sisymbrium altissimum atlas page.
CalPhotos: Sisymbrium altissimum photos.
USDA Plants: Sisymbrium altissimum information.
