Page authors: Don Knoke, David Giblin
Senecio serra
tall butterweed, butterweed groundsel

Distribution: Occurring chiefly east of the Cascades crest in Washington; Washington to California, east to Montana, Wyoming, and Colorado.

Habitat: Meadows and open, moist hillsides, foothills to mid-elevations in the mountains.

Flowers: June-August

Origin: Native

Growth Duration: Perennial

Conservation Status: Not of concern

Pollination: Bumblebees, bees, butterflies, flies, beetles


Stout, glabrous, fibrous-rooted perennial 5-20 dm. tall, stems clustered.


Numerous, not tufted toward the base, not much reduced upward, the lower leaves oblanceolate, short-petiolate, early deciduous, the others lanceolate, tapering to a short petiole, 5-15 cm. long and 1-4 cm. wide, sharply toothed.


Heads numerous on short peduncles, almost cylindric, the disk 3-7 mm. wide; involucre 6-8 mm. high, its bracts about 8 or about 13, often black-tipped; rays few, about 5 or 8, 5-8 mm. long, yellow.

Identification Notes:

Look for a tall, upright plant with large, sharply toothed leaves the length of the stem.

Accepted Name:
Senecio serra Hook.
Publication: Fl. Bor.-Amer. 1: 333. 1834.

Synonyms & Misapplications:
(none provided)
Additional Resources:

PNW Herbaria: Specimen records of Senecio serra in the Consortium of Pacific Northwest Herbaria database.

WA Flora Checklist: Senecio serra checklist entry.

OregonFlora: Senecio serra information.

E-Flora BC: Senecio serra atlas page.

CalPhotos: Senecio serra photos.

USDA Plants: Senecio serra information.

45 photographs:
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