Distribution: Near the Snake River Canyon, western Idaho, eastern Oregon and extreme southeast Washington.
Habitat: Open, often rocky slopes.
Flowers: April - July
Conservation Status: Sensitive in Washington (WANHP)
Glabrous, acaulescent, parsley-scented perennial from a stout taproot and branching, woody base, 1.5-4 dm. tall.
Leaves bright green, ternate-pinnately dissected into moderately numerous, small, flat ultimate segments 1-6 mm. long and up to 2.5 mm. wide, the segments tending to lie in the same plane.
Inflorescence of compound umbels, the rays unequal, 2-8 cm. long at maturity; involucre wanting; involucel of several well-developed, narrow bractlets; calyx teeth none; flowers yellow; pedicels 3-15 mm. long.
Fruit elliptic, 5.5-10 mm. long, glabrous, the lateral wings one-half as wide to as wide as the body.