Distribution: Occurring east of the Cascades crest in Washington chiefly in the Columbia River Basin. central Washington to northeastern Nevada, east to southwestern Idaho.
Habitat: Scablands and sagebrush steppe in rather deep soil.
Conservation Status: Not of concern
Glabrous, nearly scapose perennial from a globose-thickened taproot, the scapes up to 2 dm. tall.
Leaves all basal, pinnately dissected into numerous, crowded, rounded ultimate segments not over 5 cm. long. Taproot globose-thickened up to 3.5 cm, surmounted by an elongate, cylindrical, slender upper portion.
Inflorescence a compound umbel, the rays unequal, 2.5-7 cm. long; scapes 1-several, ascending; involucre wanting; involucel bractlets narrow and inconspicuous, 1-3 mm. long; pedicels becoming elongate, 4-15 mm. long in fruit; calyx teeth obsolete; petals white, with usually dark purple, but occasionally yellow, stamens.
Fruit glabrous, broadly elliptic, 6-10 mm. long, the thin wings about half as wide as the body.