Page authors: Don Knoke, David Giblin
Petasites frigidus
alpine butterbur, sweet coltsfoot

Distribution: Occurring in forested and mountainous areas throughout Washington; Alaska to California, east across the northern half of North America to the Atlantic Coast; circumboreal.

Habitat: Meadows, swamps, and other wet places, from low elevations to the alpine.

Flowers: March-August

Origin: Native

Growth Duration: Perennial

Conservation Status: Not of concern

Pollination: Bees, flies, beetles, wasps


Perennial from a creeping rhizome, 1-5 dm. tall, sub-dioecious, the flowers appearing before or with the leaves.


Leaves all basal, large, long-petioled, palmately veined, up to 4 dm. wide and long, glabrous above and loosely white-woolly below, lobed or coarsely toothed or both; the stem with several parallel-veined bracts, 2.5-6 cm. long, reduced upward.


Heads several to many in a somewhat congested inflorescence; involucre 5-9 mm. high, the bracts equal and in a single series; flowers in the female heads pistillate and fertile, whitish and rayless, the corolla filiform; flowers in the males heads sterile, whitish, with short rays.

Accepted Name:
Petasites frigidus (L.) Fr.
Publication: Summa Veg. Scand. 182. 1845.

Synonyms & Misapplications:
(none provided)
Additional Resources:

PNW Herbaria: Specimen records of Petasites frigidus in the Consortium of Pacific Northwest Herbaria database.

WA Flora Checklist: Petasites frigidus checklist entry.

OregonFlora: Petasites frigidus information.

E-Flora BC: Petasites frigidus atlas page.

CalPhotos: Petasites frigidus photos.

USDA Plants: Petasites frigidus information.

109 photographs:
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