Page authors: Don Knoke, David Giblin
Agastache occidentalis
western giant-hyssop

Distribution: East slopes of the Cascades, Chelan to Yakima Counties, Washington; south to Oregon.

Habitat: Dry, open, often rocky slopes at low to moderate elevations.

Flowers: June-August

Origin: Native

Growth Duration: Perennial

Conservation Status: Not of concern


Perennial herbs from fibrous roots and branching, woody base, the numerous, square stems simple or branched, 4-8 dm. tall, glabrous or finely puberulent.


Leaves opposite, petioles 1-5 cm. long, the blades ovate to deltoid, with rounded teeth, up to 6 cm. long and 4 cm. wide, glabrous or finely scabrous on the upper surface, and with very short, fine, tangled-woolly hairs on the lower surface.


Inflorescence spike-like, 3-15 cm. long; calyx prominently veined, the 5 equal teeth 3-5 mm. long, narrowly triangular, acuminate, usually tinged with lavender-purple; corolla whitish to lavender, 10-14 mm. long, two-lipped, with short lobes; stamens 4, exerted, the upper pair longer than the lower; style slender, 2-parted; ovary superior, 2-celled.


Fruit of 4 nutlets.

Accepted Name:
Agastache occidentalis (Piper) A. Heller
Publication: Muhlenbergia; a journal of botany 1(1): 4. 1900.

Synonyms & Misapplications:
(none provided)
Additional Resources:

PNW Herbaria: Specimen records of Agastache occidentalis in the Consortium of Pacific Northwest Herbaria database.

WA Flora Checklist: Agastache occidentalis checklist entry.

OregonFlora: Agastache occidentalis information.

E-Flora BC: Agastache occidentalis atlas page.

CalPhotos: Agastache occidentalis photos.

USDA Plants: Agastache occidentalis information.

31 photographs:
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