Distribution: Occurring east of the Cascades crest in Washington; Alaska to California, east to the Rocky Mountains; throughout most of Canada and the central, southeastern, and northeastern regions of the U.S.
Habitat: Fens, wetlands, shorelines, and damp woodlands, often where calcareous.
Flowers: May-June
Origin: Native
Growth Duration: Perennial
Conservation Status: Sensitive in Washington (WANHP)
Sparsely pubescent, perennial herbs, the stems 1.5-4 dm. tall, glandular, leafy throughout.
Leaves alternate, broadly elliptic to elliptic-lanceolate, 6-17 cm. long and up to 7 cm. wide, sessile and slightly sheathing.
Flower solitary, terminal, subtended and usually exceeded by an erect, leaf-like bract; sepals and petals greenish-yellow to purplish-brown, wavy-margined, the upper sepal the largest, 2.5-4 cm. long, the lower pair completely fused; 2 small petals narrower and longer than the sepals; the third petal (lip) pouch-like, 2-3 cm. long, yellow, often purplish-dotted around the orifice; fertile stamens 2, the third sterile stamen petal-like, up to 10 mm. long, triangular, lobed at the base.
Capsule.
Publication: Trans. Linn. Soc. London, Bot. 1: 77, plate 2, fig. 2. 1791.
- var. makasin – mocassin yellow lady's-slipper Occurring east of the Cascades crest in Washington; Alaska to California, east to the Rocky Mountains, but not the southern Rocky Mountains; throughout most of Canada and the central, southeastern, and northeastern regions of the U.S.
- var. pubescens – hairy yellow lady's-slipper Occurring east of the Cascades crest in Washington; Alaska to Oregon, east to the Rocky Mountains; throughout most of Canada and the central, southeastern, and northeastern regions of the U.S.
PNW Herbaria: Specimen records of Cypripedium parviflorum in the Consortium of Pacific Northwest Herbaria database
WA Flora Checklist: Cypripedium parviflorum checklist entry
OregonFlora: Cypripedium parviflorum information
E-Flora BC: Cypripedium parviflorum atlas page
CalPhotos: Cypripedium parviflorum photos
