Platanthera ephemerantha R.M.Bateman

White Flower Rein Orchid

Facts About

Accepted Synonym: Piperia candida

Platanthera ephemerantha, commonly known as White Flower Rein Orchid, is confined to western North America, from southeast Alaska to northern California. It grows in coniferous and mixed forests or chaparral usually within 150 km of the coast. This orchid grows up to 60 cm, generally with less than 6 stem bracts and basal leaves that often wilt during flowering. The spike has up to 100 small, faintly fragrant white flowers. Although the petals are straight, the lateral sepals are bent downward and twisted. The labellum is curved backward with a short, tapered nectar spur. The white, ephemeral flowers distinguish this orchid from Platanthera unalascensis which has pale green flowers.

Platanthera ephemerantha is considered vulnerable and is threatened by development and lumbering in North America.


Pollinator information for this orchid has not been reported.

Ecosystem Type



Leaf arrangement:
Form of the labellum:
the labellum is not pouch-like
Labellum outline:
the labellum is simple
Main color of labellum:
Nectar spur:
Inflorescence type:
the inflorescence is a spike
Labellum characteristics:
the labellum is simple
Labellum length:
2–3 mm
Sepal length:
1.8–3.5 mm
Plant height:
10–60 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 May Be At Risk

North America Distribution

Adapted from USDA data