Distribution: East of the Cascades in Washington; British Columbia to California, east to Idaho and Nevada.
Habitat: Rock cliffs and dry, rocky areas.
Conservation Status: Not of concern
Glabrous and glaucous biennial, the stem often hollow, usually freely-branched, 3-25 dm. tall.
Leaves rather fleshy, the basal ovate to deltoid-lanceolate, 1-4.5 dm. long, long-petiolate, sharply and deeply lobed; cauline leaves alternate, numerous, reduced upward, pinnatifid to nearly entire.
Inflorescence of bractless, elongate racemes; pedicles stout, 2-5 mm. long, spreading; sepals 4, erect, 3.5-7 mm. long, greenish-white to purplish, sometimes saccate at the base; petal 4, white, 6-20 mm. long, linear to narrowly spatulate; stamens 6, the filaments flattened, distinct, shorter than the sepals; style 1-3 mm. long.
Siliques spreading, straight to strongly curved, 4-14 cm. long and about 1 mm. thick, on a stipe 1-4 mm. long; seeds in 1 series.