Distribution: Occurring chiefly east of the Cascades crest in Washington; southern British Columbia to northeast Oregon, east to southeastern Alberta, western Montana, and Wyoming.
Habitat: Open, often rocky slopes and flats, from the foothills to middle elevations in the mountains.
Flowers: May-July
Origin: Native
Growth Duration: Biennial, Perennial
Conservation Status: Not of concern
Pollination: Bees, flies, butterflies, beetles, wasps
Usually branched, glabrous perennial from a taproot, 1-8 dm. tall.
Leaves basal and cauline or all cauline, ternately or ternate-pinnately 2-several times divided into narrow, unequal ultimate segments, the longer segments 1-8 cm. long and up to 5 mm. wide, the smallest ones only 1-2 mm. long. Taproot short and tuberous-thickened or long and slender, occasionally with 2 or more enlarged sections.
Inflorescence a compound umbel, the rays 3-10 cm. long; involucre and involucel wanting; calyx teeth obsolete, flowers yellow; pedicels 4-13 mm. long.
Fruit glabrous, narrowly oblong, 5.5-12 mm. long and 1.5-3.3 mm. wide; the wings evident but narrow, 0.3-0.5 mm. wide.
PNW Herbaria: Specimen records of Lomatium ambiguum in the Consortium of Pacific Northwest Herbaria database
WA Flora Checklist: Lomatium ambiguum checklist entry
OregonFlora: Lomatium ambiguum information
E-Flora BC: Lomatium ambiguum atlas page
CalPhotos: Lomatium ambiguum photos