Cypripedium parviflorum Salisb.

Yellow Lady's Slipper

Facts About

Accepted Synonyms: Cypripedium calceolus var. pubescens, Cypripedium pubescens

Cypripedium parviflorum, commonly known as Yellow Lady's Slipper, is found across virtually all of the United States and Canada, from Alaska to Georgia. It is a widely variable species, with four varieties and multiple hybrids, making identification and delimitation difficult. It produces a large flower with a pale to dark yellow (and very rarely white) pouch-like labellum, which sometimes has reddish spots on the interior. Green or yellowish sepals and petals twist outwards in spirals. It produces up to five stem leaves; both the stem and leaves are covered in thin hairs. It grows in dry to mesic forests, woodlands, fens, prairies, and meadows. It produces a natural hybrid with C. candidum, C. × andrewsii, and may hybridize with C. montanum to produce C. × columbianum.

Cypripedium parviflorum is considered globally secure and is common or widespread throughout much of its range.


This orchid has many documented pollinators including species found in Agapostemon, Andrena, Apis, Ceratina, Eristalis, Osmia and Lasioglossum. Differences in fragrance and flower size between the varieties of this orchid may account for variation in insect pollinators. For example Cypripedium parviflorum var. pubescens is pollinated by Ceratina calcarata. Cypripedium parviflorum var. makasin is likely pollinated by Lasioglossum rohweri, although the anther exit hole can also accommodate the small bee, Ceratina calcarata.

Notes on Subspecies and Varieties

There are four varieties of Cypripedium parviflorum:
Cypripedium parviflorum var. parviflorum is limited in distribution to the central mid-Atlantic and produces relatively small flowers.
Cypripedium parviflorum var. makasin is found in northeastern and central U.S. and Canada and has strongly scented flowers.
Cypripedium parviflorum var. pubescens, has an extended, more southerly range than C. var. makasin and larger flowers than C. var parviflorum.
Cypripedium parviflorum var. exiliens is restricted to northern Alaska where it is considered rare and imperiled and extends into northwest Canada.

Ecosystem Type

Bogs, fens, forests, meadows, swamps, woodlands


Leaf arrangement:
Number of leaves on stem:
  • two
  • three
  • four
  • five
Form of the labellum:
the labellum is pouch-like
Labellum outline:
the labellum is simple
Main color of labellum:
  • white
  • yellow
Nectar spur:
Inflorescence type:
the inflorescence has one flower or a pair of flowers
Labellum characteristics:
the labellum is saccate
Labellum length:
15–54 mm
Sepal length:
11–80 mm
Plant height:
12–80 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