Page author: David Giblin
Polemonium occidentale
western polemonium

Distribution: Occurring chiefly east of the Cascades crest in Washington; British Columbia south to California, east to Montana and Colorado.

Habitat: Very wet places at mid-elevations in the mountains.

Flowers: June-August

Origin: Native

Growth Duration: Perennial

Conservation Status: Not of concern


Perennial with a solitary stem from the end of a short, horizontal rhizome, the stem 4-10 dm. tall.


Basal and lower cauline leaves well developed and rather long-petiolate, with 11-27 lanceolate and acute leaflets 1-4 cm. long and 2-13 mm. wide, somewhat reduced upward.


Flowers crowded in an elongate inflorescence; calyx herbaceous, 5-8 mm. long, the 5 lobes about equaling the tube; corolla blue, 1-1.6 cm. long and wide, the 5 lobes longer than the tube; style 3-parted, exserted and surpassing the stamens; ovary superior.


Capsule 3-celled.

Accepted Name:
Polemonium occidentale Greene

Synonyms & Misapplications:
Polemonium caeruleum L. ssp. amygdalium (Wherry) Munz
Polemonium caeruleum L. ssp. occidentale (Greene) J.F. Davidson
Polemonium caeruleum L. var. pterospermum Benth.
Polemonium helleri Brand
Polemonium intermedium (Brand) Rydb.
Polemonium occidentale Greene ssp. amygdalium Wherry
Polemonium occidentale Greene ssp. occidentale [JPM2]
Polemonium occidentale Greene ssp. typicum Wherry
Additional Resources:

PNW Herbaria: Specimen records of Polemonium occidentale in the Consortium of Pacific Northwest Herbaria database.

WA Flora Checklist: Polemonium occidentale checklist entry.

OregonFlora: Polemonium occidentale information.

E-Flora BC: Polemonium occidentale atlas page.

CalPhotos: Polemonium occidentale photos.

USDA Plants: Polemonium occidentale information.

34 photographs:
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