Lady's Slipper Orchids
Lady's slipper orchids (Cypripedioideae) (also known as lady slipper orchids or slipper orchids) are orchids in the subfamily Cypripedioideae, which includes the genera Cypripedium, Mexipedium, Paphiopedilum, Phragmipedium and Selenipedium. They are characterised by the slipper-shaped pouches (modified labellums) of the flowers – the pouch traps insects so they are forced to climb up past the staminode, behind which they collect or deposit pollinia, thus fertilizing the flower. Unlike other orchids, Cypripedioideae have two fertile anthers — they are "diandrous".
This subfamily has been considered by some to be a family Cypripediaceae, separate from the Orchidaceae.
The subfamily Cypripedioideae is monophyletic and consists of five genera.
The Cypripedium genus is found across much of North America, as well as in parts of Europe and Asia. The state flower of Minnesota is the Showy Lady's Slipper (Cypripedium reginae). The Lady's Slipper is also the official provincial flower of the Canadian province of Prince Edward Island.
Paphiopedilums are found in the tropical forests of southeast Asia reaching as far north as southern China. Paphiopedilum is quite easy to cultivate and therefore is popular among orchid enthusiasts. In fact, overcollecting of this genus has been so extensive that many species are now sub-viable in their natural habitats.
Phragmipedium, found across northern South and Central America, is also easy to cultivate as it requires lower temperatures than Paphiopedilum, eliminating the need for a greenhouse in many areas.
The lady's slipper is also known in the United States of America as the moccasin flower, from its resemblance to a moccasin.