Cypripedioideae includes the genera Cypripedium, Mexipedium, Paphiopedilum, Phragmipedium and Selenipedium.

[1] 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.

The leaves are arranged spirally or in two rows, the shoot is slender or compressed.

[citation needed] The species in this subfamily form trap flowers in which insect access to the saclike lip from the front is quite easy.

[3] Around the year 2000, molecular phylogenetics and DNA sampling have come to play an increasingly important role in classification.

[4] This has led to the conclusion that recognition of a distinct family Cypripediaceae would be inappropriate.