Distribution: Occurring east of the Cascades crest in central Washington, where endemic to Benton, Grant, Kittitas, and Yakima counties. Scattered locations in Yakima County, Washington, and adjacent counties.
Habitat: Rocky slopes and talus fields at middle elevations .
Flowers: March-April
Origin: Native
Growth Duration: Perennial
Conservation Status: Sensitive in Washington (WANHP)
Pollination: Bees, flies, butterflies, beetles, wasps
Scapose, glabrous and glaucous perennial from a tuberous-thickened root, the scape erect, 1-3 dm. tall.
Leaves all basal, ternate-pinnately dissected into numerous, small, crowded, blunt ultimate segments 2-8 mm. long; bladeless basal sheathes very large and conspicuous, but the remnants from previous year not prominent.
Inflorescence a compound umbel, the rays 5-13, up to 8 cm. long at maturity; involucre none; involucel of a few narrow, inconspicuous bractlets; flowers mustard yellow, becoming reddish with age. Hitchcock et. al. incorrectly refers to the flower color as purple.
Fruit elliptic-oval, reddish along the wings, 9-11 mm. long, the lateral wings thickened and less than 1 mm. wide.
PNW Herbaria: Specimen records of Lomatium tuberosum in the Consortium of Pacific Northwest Herbaria database
WA Flora Checklist: Lomatium tuberosum checklist entry
OregonFlora: Lomatium tuberosum information
E-Flora BC: Lomatium tuberosum atlas page
CalPhotos: Lomatium tuberosum photos