Page authors: Don Knoke, David Giblin
Petasites frigidus
alpine butterbur, sweet coltsfoot
WTU specimens
Other herbaria

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

Conservation Status: Not of concern

Description:
General:

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

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.

Flowers:

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)
Infraspecies:
var. frigidus – alpine butterbur, arctic butterbur, sweet coltsfoot    Occurring in the Olympic and Cascades Mountains in Washington; Alaska to northern Oregon, east to Saskatchewan.
var. palmatus – western coltsfoot    Occurring chiefly west of the Cascades crest in Washington, also in the Blue Mountains of southeast Washington; British Columbia to northeast Oregon, east across Canada to the Atlantic Coast.
var. sagittatus – arrowhead sweet coltsfoot, arrowleaf coltsfoot    Occurring east of the Cascades crest along the northern border in Washington; Alaska to northeastern Washington, east to the northern Great Plains, Great Lakes region, and northeastern North America.
Additional Resources:

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

WA Flora Checklist: Petasites frigidus checklist entry.

E-Flora BC: Petasites frigidus atlas page.

CalPhotos: Petasites frigidus photos.

USDA Plants: Petasites frigidus information.

82 photographs:
Group by