Page authors: Don Knoke, David Giblin
Senecio triangularis
arrowleaf groundsel, arrowleaf ragwort
WTU specimens
Other herbaria

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

Habitat: Moist places and streambanks, moderate to high elevations in the mountains, and low elvations west of the Cascades.

Flowers: June-September

Origin: Native

Conservation Status: Not of concern


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. 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.

E-Flora BC: Senecio triangularis atlas page.

CalPhotos: Senecio triangularis photos.

USDA Plants: Senecio triangularis information.

53 photographs:
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