Platanthera chorisiana (Cham.) Rchb.f.

Chamisso's Orchid, Choris Bog Orchid

Facts About

Accepted Synonyms: Habenaria chorisiana, Limnorchis chorisiana, Peristylus chorisianus, Platanthera ditmariana, Platanthera matsudae, Pseudodiphryllum chorisianum

Platanthera chorisiana, commonly known as Chamisso's Orchid, ranges from Washington state, north and west along the Pacific coast, through the Aleutians, to Kamchatka and Japan. The slightly bent stem grows up to 20 cm and has 1 or 2 sharply pointed bracts. The spike has fragrant, very small greenish flowers. The dorsal sepals, petals and labellum form a small ball-shaped flower that barely opens. A tiny blunt spur projects from behind the flower. This orchid prefers wet tundra, meadows, bogs, fens, and mossy stream banks.

Platanthera chorisiana is considered globally vulnerable.


Pollinator information for this orchid has not been reported in North America but in other parts of it range this orchid is pollinated by Oedemeronia lucidicollis. While the beetle is collecting nectar and pollen, pollinia attach to the antennae and around the mouth. Other small insects could also be pollinators.

Ecosystem Type

Alpine or subalpine zones, bogs, fens, meadows, stream bank, tundra


Leaf arrangement:
Number of leaves on stem:
  • two
  • three
  • four
Form of the labellum:
the labellum is not pouch-like
Labellum outline:
the labellum is simple
Main color of labellum:
green to brown
Nectar spur:
Inflorescence type:
the inflorescence is a spike
Labellum characteristics:
the labellum is simple
Labellum length:
1.5–2.5 mm
Sepal length:
1.5–2 mm
Plant height:
6–20 cm
Show All Characteristics

Native to North America


North American Conservation Status & Distribution

Conservation Status

Select a location to view conservation status:

Conservation and Wetland Status
Global Rank Vulnerable
US Status N/A
Canadian Status Secure

North America Distribution

Adapted from USDA data