Page authors: Don Knoke, David Giblin
Lomatium cous
cous, cous-root desert-parsley
WTU specimens
Other herbaria

Distribution: Southeast Washington and northeast Oregon,east through Idaho to Montana and Wyoming

Habitat: Dry, open, often rocky places often with sagebrush; common at low elevations, occasionally found much higher

Flowers: April - July

Origin: Native

Conservation Status: Not of concern


Glabrous or short-hairy, glaucous perennial from a taproot, usually acaulescent, 1-3.5 dm. tall at maturity.


Leaves pinnately dissected, the ultimate segments varying from short, crowded and broad to longer and narrower, up to 15 mm. long and 3 mm. wide; leaves usually all basal, but there may be one or more cauline leaves. The taproot is usually short and tuberous-thickened, but occasionally more slender and elongate.


Inflorescence a compound umbel, the rays 5-20, unequal, 1.5-10 cm. long at maturity; involucre none; involucel bractlets well-developed, broadly oblanceolate to obovate, 2-5 mm. long, entire or few-toothed, often purplish; calyx teeth obsolete, flowers yellow; pedicels short, 1-3 mm. long.


Fruit oblong to broadly elliptic, 5-12 mm. long and 3-5 mm. wide, often roughened; lateral wings about equaling the body; dorsal wings sometimes present.

Accepted Name:
Lomatium cous (S. Watson) J.M. Coult. & Rose

Synonyms & Misapplications:
Lomatium circumdatum (S. Watson) J.M. Coult. & Rose
Lomatium montanum J.M. Coult. & Rose
Additional Resources:

PNW Herbaria: Specimen records of Lomatium cous in the Consortium of Pacific Northwest Herbaria database.

WA Flora Checklist: Lomatium cous checklist entry.

E-Flora BC: Lomatium cous atlas page.

CalPhotos: Lomatium cous photos.

USDA Plants: Lomatium cous information.

38 photographs:
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