Distribution: Occurring east of the Cascades crest in northeastern Washington; Alaska to Washington, east across Canada and the northern U.S. to New England.
Habitat: Rocky and sandy soil, prairies to open forest.
Conservation Status: Review Group 1 in Washington (WANHP)
Short-lived perennials or biennials, caudex present or not; stems simple from each caudex branch, 20-120 cm tall, glabrous or pubescent near base with simple trichomes, sessile or nearly so, usually 2-3-rayed, 0.1-0.3 mm, glabrous distally.
Basal leaves oblanceolate, 1.5-10 mm broad, margins entire or toothed, ciliate near base, simple trichomes to 1 mm, sparsely to densely pubescent above and beneath, 2-4-rayed trichomes sessile or nearly so and 0.2-0.6 mm; cauline leaves 13-52, commonly hiding stem near base, lobe-like appendages at base 1-5 mm, surfaces becoming glabrous towards ends of stems.
Inflorescence 16-88-flowered, typically unbranched racemes; fruiting pedicels spreading-ascending to descending, commonly curving downward gently, uncommonly not curved, 5-22 mm, glabrous, not secund; flowers spreading apart; sepals 4, glabrous or pubescent; petals 4, white to uncommonly pale purple, 5.5-8 mm long and 1-2 mm broad, glabrous; pollen spheroid.
Siliques 3.5-9 cm long and 1-1.8 mm broad, spreading-ascending to pendent, not appressed to rachis, slightly curved or not, with parallel edges; valves glabrous; seeds in 1 series or nearly 2 series, 1-1.8 mm long and 0.8-1.2 mm broad, with a continuous wing to 0.25 mm broad.