The subfamily Cypripedioideae is monophyletic and consists of five genera: Cypripedium, Mexipedium, Paphiopedilum, Phragmipedium and Selenipedium. Members of this subfamily are often called Lady Slippers (aka Lady's Slipper, Lady's-slipper, Ladyslipper). This subfamily has been considered by some (Rasmussen, 1985) to be a family Cypripediaceae, separate from the Orchidaceae.