Page authors: Don Knoke, David Giblin
Platanthera unalascensis
Alaska rein-orchid

Distribution: Widely distributed on both sides of the Cascades crest in Washington; Alaska to California, east to the Rocky Mountains and Nebraska, also from the Great Lakes to the Atlantic Coast.

Habitat: Dry, open woods and gravelly streambanks, low to mid-elevations in the mountains.

Flowers: June-August

Origin: Native

Conservation Status: Not of concern


Scapose perennials with 1-2 fleshy tubers, glabrous, 2-6 dm. tall.


Leaves 2-4 on the lower third of the stem, often all basal, narrowly lanceolate to broadly oblanceolate, 8-15 cm. long and 10-30 mm. broad, acute to rounded, gradually narrowed to the sheathing base.


Inflorescence a loosely- to densely-flowered, spike-like raceme; floral bracts inconspicuous, seldom over 8 mm. long; flowers sub-sessile, very numerous, spirally arranged; sepals 1-nerved, thin, pale green, the upper one ovate, about 3 mm. long, the lower pair longer but narrower, spreading; petals thicker than the sepals, greenish to nearly white, about equal to the upper sepal, oblong-lanceolate, oblique; lip fleshy, narrowly lanceolate to triangular-ovate, 2.5-4.5 mm. long, fused with the lateral sepals; spur narrowly cylindric, straight, 3-5 mm. long; stamens and style fused to form a very short column.


Capsule erect, scarcely 1 cm. long

Accepted Name:
Platanthera unalascensis (Spreng.) Kurtz
Publication: Bot. Jahrb. Syst. 19(4): 408. 1894.

Synonyms & Misapplications:
Habenaria schischmareffiana Cham.
Habenaria unalascensis (Spreng.) S. Watson [HC]
Habenaria unalaschensis (Spreng.) S. Watson, orthographic variant
Piperia unalascensis (Spreng.) Rydb. [FNA26]
Platanthera foetida Geyer ex Hook.
Platanthera unalaschcensis (Spreng.) Kurtz, orthographic variant
Spiranthes unalascensis Spreng.
Additional Resources:

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

WA Flora Checklist: Platanthera unalascensis checklist entry.

E-Flora BC: Platanthera unalascensis atlas page.

CalPhotos: Platanthera unalascensis photos.

USDA Plants: Platanthera unalascensis information.

39 photographs:
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