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

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-July

Origin: Native

Conservation Status: Not of concern

Description:
General:

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.

Leaves:

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.

Flowers:

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)
Infraspecies:
var. exaltatus – one-stemmed butterweed, lambs-tongue groundsel, tall western groundsel    Occurring east of the Cascades crest in Washington; British Columbia to California, east to the Rocky Mountains.
var. ochroleucus – white western groundsel    Occurring chiefly east of the Cascades crest and in the Columbia River Gorge in Washington; British Columbia to California, east to Montana.
Additional Resources:

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

WA Flora Checklist: Senecio integerrimus checklist entry.

E-Flora BC: Senecio integerrimus atlas page.

CalPhotos: Senecio integerrimus photos.

USDA Plants: Senecio integerrimus information.

108 photographs:
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