Photos courtesy of Ethan Muller

Large Yellow Lady Slipper (Cypripedium parviflorum)

Appearance & ID Tips
Perennial with pubescent stems and leaves; stem 20-80 cm. Leaves alternate, clasping/sheathing stem, oval to lance-ovate, 6-20 cm long, half as wide. Flowers 1-2, each subtended by an erect foliaceous bract; lip inflated, bright yellow, often purple-veined; lateral petals red-purple, long-lanceolate, usually twisted.

Flowers late May to June

Wetland indicator: Facultative Wetland Species

Bogs, swamps, moist to wet woods. Slightly acid to neutral pH, sometimes on limestone. Plants in the north can be found in open areas.

Conservation Status
Declining and listed as Exploitably Vulnerable in NY.       

This is one of the most widely distributed lady’s slippers but by no means common; can be quite abundant where growing conditions are favorable. Reputed to be easier to grow in a garden setting than many other orchids, although it is best (and most ethical) to use greenhouse grown plants since transplanting can disrupt mycorrhizal associations; orchids transplanted from the wild often perish.