Original: 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 fertilising the flower .
Simplified: They are special because of the slipper-shaped orchid pouches of the flowers . The pouch traps insects so that they must climb up past the staminode , where they get or give pollen , fertilizing the flower .