Page authors: Don Knoke, David Giblin
Senecio integerrimus
one-stemmed butterweed, western groundsel

Distribution: Occurring chiefly east of the Cascades crest in Washington, where widely distributed; British Columbia to California, east to the Great Plains and Great Lakes region.

Habitat: Meadows and seasonally moist open areas from low elevations to the subalpine.

Flowers: May-August

Origin: Native

Growth Duration: Perennial

Conservation Status: Not of concern

Pollination: Bumblebees, bees, butterflies, flies, beetles


Stout, fibrous-rooted perennial from a very short crown; stems solitary, 2-7 dm. tall; plants covered with white, loose hairs when young, but these missing in older plants except in the leaf axils.


Usually entire, elliptic to broadly lanceolate, the basal ones petiolate, the blade and petiole 6-25 cm. long and 1-6 cm wide; cauline leaves progressively reduced upward, becoming sessile toward the top of the stem.


Heads several to numerous in a rather congested inflorescence; involucre 5-10 mm. long; rays 6-15 mm. long, usually yellow, occasionally cream.

Identification Notes:

A Senecio growing on dry ground, with a fairly tall, single, upright stem and large, entire leaves is probably this species, especially if the leaves are lightly covered with white, tangled hairs.

Accepted Name:
Senecio integerrimus Nutt.
Publication: Gen. N. Amer. Pl. 2: 165. 1818.

Synonyms & Misapplications:
(none provided)
Additional Resources:

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

WA Flora Checklist: Senecio integerrimus checklist entry

OregonFlora: Senecio integerrimus information

E-Flora BC: Senecio integerrimus atlas page

CalPhotos: Senecio integerrimus photos

149 photographs:
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