Cypripedioideae

Cypripedioideae is a subfamily of orchids commonly known as '''lady's slipper orchids, lady slipper orchids or slipper orchids'. Cypripedioideae includes the genera Cypripedium, Mexipedium, Paphiopedilum, Phragmipedium and Selenipedium''. They are characterised by the slipper-shaped pouches (modified labella) 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. There are approximately 165 species in the subfamily.

Selenipedium is a genus of the orchid family (Orchidaceae) (Subfamily Cypripedioideae). The genus has been given its own tribe, Selenipedieae, and subtribe, Selenipediinae. It is abbreviated Sel in trade journals.

Mexipedium is a monotypic genus of the orchid family Orchidaceae, subfamily Cypripedioideae, consisting of only one species, Mexipedium xerophyticum. It is also the sole genus of tribe Mexipedieae and subtribe Mexipediinae.