Page authors: Don Knoke, David Giblin
Platanthera chorisiana
choriso bog orchid

Distribution: Occurring west of the Cascades crest, where known only from Snohomish County in Washington; Aleutian Islands to Vancouver Island, British Columbia, and in Snohomish County, Washington.

Habitat: Moist areas, especially at the edges of streams and bogs.

Flowers: July-August

Origin: Native

Conservation Status: Threatened in Washington (WANHP)


Scapose perennials from spindle-shaped, fleshy roots, the scape 5-15 cm. tall.


Leaves 2 or 3, basal, sheathing, ovate to elliptic-lanceolate, 2.5-6 cm. long and about 1/3 as broad, occasionally with 1 or 2 lanceolate bracts up to 2 cm. long on the scape.


Inflorescence a crowded spike, the 5-18 greenish flowers sessile, the lower ones exceeded by lanceolate, greenish bracts up to 12 mm. long; sepals about 2 mm. long, oblong, 1-nerved, the upper one slightly hooded; petals strongly 3-nerved, slightly shorter and broader than the sepals; lip 1.5-2 mm. long and broad, concave, erect; spur saccate, about 1 mm. long, slightly curved; stamens and style fused to form a stout column about 1 mm. long.

Accepted Name:
Platanthera chorisiana (Cham.) Rchb. f.
Publication: Icon. Fl. Germ. Helv. 13–14: 128. 1851.

Synonyms & Misapplications:
Habenaria chorisiana Cham. [HC]
Limnorchis chorisiana (Cham.) J.P. Anderson
Pseudodiphryllum chorisianum (Cham.) Nevski
Additional Resources:

PNW Herbaria: Specimen records of Platanthera chorisiana in the Consortium of Pacific Northwest Herbaria database.

WA Flora Checklist: Platanthera chorisiana checklist entry.

E-Flora BC: Platanthera chorisiana atlas page.

CalPhotos: Platanthera chorisiana photos.

USDA Plants: Platanthera chorisiana information.

6 photographs:
Group by