Page authors: Don Knoke, David Giblin
Symphyotrichum spathulatum
western aster, western mountain aster

Distribution: Occurring chiefly east of the Cascades crest in Washington; British Columbia to California, east to the Rocky Mountains.

Habitat: Meadows and forest openings, from middle elevations to the subalpine.

Flowers: July-September

Origin: Native

Conservation Status: Not of concern


Fibrous-rooted perennial from a creeping rhizome, the stems 2-10 dm. tall.


Leaves glabrous and entire, the lower ones oblanceolate and petiolate, the others narrower and sessile, 3-15 cm. long and 3-10 mm. wide.


Heads 1-many in a flat-topped inflorescence; involucre 5-7 mm. high, its bracts usually pointed, narrow, linear or linear-oblong, green to the base and minutely purple-tipped; disk flowers numerous, yellow; rays 20-50, blue or violet, 6-15 mm. long; pappus of numerous capillary bristles.


Achenes hairy.

Accepted Name:
Symphyotrichum spathulatum (Lindl.) G.L. Nesom
Publication: Phytologia. 77: 291. 1995.

Synonyms & Misapplications:
Aster occidentalis (Nutt.) Torr. & A. Gray [HC]
Aster occidentalis (Nutt.) Torr. & A. Gray var. intermedius A. Gray [HC]
Aster occidentalis (Nutt.) Torr. & A. Gray var. occidentalis [HC]
Aster spathulatus Lindl. var. spathulatus
Aster vallicola Greene
Symphyotrichum spathulatum (Lindl.) G.L. Nesom var. intermedium (A. Gray) G.L. Nesom [FNA20]
Symphyotrichum spathulatum (Lindl.) G.L. Nesom var. spathulatum [FNA20]
Symphyotrichum spathulatum (Lindl.) G.L. Nesom var. yosemitanum (A. Gray) G.L. Nesom [FNA20]
Additional Resources:

PNW Herbaria: Specimen records of Symphyotrichum spathulatum in the Consortium of Pacific Northwest Herbaria database.

WA Flora Checklist: Symphyotrichum spathulatum checklist entry.

E-Flora BC: Symphyotrichum spathulatum atlas page.

CalPhotos: Symphyotrichum spathulatum photos.

USDA Plants: Symphyotrichum spathulatum information.

33 photographs:
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