Page authors: Don Knoke, David Giblin
Senecio triangularis
arrowleaf groundsel, arrowleaf ragwort

Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east to the Rocky Mountains.

Habitat: Moist places and streambanks from the lowlands to the subalpine.

Flowers: June-September

Origin: Native

Growth Duration: Perennial

Conservation Status: Not of concern

Pollination: Bumblebees, bees, butterflies, flies, beetles


Several-stemmed, glabrous, fibrous-rooted perennial 3-15 dm. tall.


Numerous, not tufted at the base nor strongly reduced upward, the lower triangular to triangular-cordate, long-petiolate, the upper with shorter petioles and narrower blades; leaf blades 4-20 cm. long and 2-10 cm. wide, usually strongly toothed.


Heads several in a short, flat-topped inflorescence; involucre 7-10 mm high, the principle bracts usually 13 but occasionally about 8. rays mostly 8, sometimes fewer, 7-13 mm. long, yellow.

Identification Notes:

The large, numerous, toothed, triangular leaves on a tall, lush plant growing in a wet area in the mountains will usually identify this species.

Accepted Name:
Senecio triangularis Hook.
Publication: Fl. Bor.-Amer. 1: 332, plate 115. 1834.

Synonyms & Misapplications:
Senecio triangularis Hook. var. angustifolius G.N. Jones [HC]
Additional Resources:

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

WA Flora Checklist: Senecio triangularis checklist entry

OregonFlora: Senecio triangularis information

E-Flora BC: Senecio triangularis atlas page

CalPhotos: Senecio triangularis photos

73 photographs:
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