Cypripedium passerinum Richardson

Sparrow's Egg Lady's Slipper

Facts About

Accepted synonyms: Cypripedium passerinum var. minganense

Cypripedium passerinum, commonly known as the Sparrow's Egg Lady's Slipper, is found throughout the interior of Alaska, across Canada to Hudson Bay, and south to northern Montana. C. passerinum is pubescent, and produces one or two small flowers on a leafy stem. The small white flower has straight petals and a green dorsal sepal covering the egg-shaped labellum. Purple spots appear on the labellum's base, orifice, and interior wall. The green flower bract is prominent and upright. This orchid grows in moist coniferous forests, mixed woodlands, sphagnum bogs, thickets, stream banks, and lake margins.

Cypripedium passerinum is considered globally secure.


Unlike other Lady's Slippers, This species is self-fertilizing and does not require a pollinator for reproduction. The stigma and anthers develop in such a way that they are in contact with each other.

Ecosystem Type

Bogs, floodplains, forests, shrublands or thickets, tundra, woodlands


Leaf arrangement:
Number of leaves on stem:
  • three
  • four
  • five
Form of the labellum:
the labellum is pouch-like
Labellum outline:
the labellum is simple
Main color of labellum:
Nectar spur:
Inflorescence type:
the inflorescence has one flower or a pair of flowers
Labellum characteristics:
  • the labellum is saccate
  • the labellum is simple
Labellum length:
12–20 mm
Sepal length:
15–20 mm
Plant height:
12–50 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 Secure
US Status N/A
Canadian Status Secure

North America Distribution

Adapted from USDA data