yellow lady's-slipper

noun
  1. a showy orchid, Cypripedium calceolus, of eastern North America, having purple-tinged yellow flowers with an inflated lip petal.

Origin of yellow lady's-slipper

An Americanism dating back to 1730–40
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018