Lady's Slipper (Cypripedium), a genus of plants of the natural order Orchidæ, of which one species, C. Calceolus, is a native of Britain, being found in a few places in the north of England, and is reckoned one of the most beautiful of the British orchids. The genus is remarkable for the large inflated lip of the corolla. Several very beautiful species are natives of the colder parts of North America. C. spectabilis is a North American species; C. barbatum, a native of Java. Both are in cultivation, the former in hardy collections, the latter in hot-houses.