The classification of the yellow lady's-slipper orchids has not been settled. Formerly, they were considered to be the same species as Eurasian yellow lady's-slippers -- Cypripedium calceolus. The modern trend is to separate the American plants from the Eurasian, but the number of American species is under debate. Some botanists recognize two species in northeastern U.S. -- Cypripedium parviflorum and Cypripedium pubescens, but these species are defined differently by different authorities. Following the Flora of North America, it is best classified as Cypripedium parviflorum it is classified as a species of special concern in Alabama.