Horror, Sleaze and Trash.

The Complex Structure of Bucket Orchids
Orchids of the genus Coryanthes have evolved along with orchid bees, and depend on each other for reproduction.
Male bees are attracted to an pheromone laced wax produced under the orchid’s helmet. The wax is stored by the male and are used in courtship. However, the helmet is slippery and bees sometimes fall into the fluid filled bucket below.
Once in the bucket, their wings are wet, which prevent them from flying. The walls of the bucket are smooth and lined with downward pointing hairs, preventing the insect from escaping through climbing. A small opening towards the front of the flower is the only way out.
As the bee climbs through the narrow opening, they must press their bodies against sticky pollen packets. These are essentially glued to the bee’s body as it tries to escape. In order for fertilisation to happen, the pollen from one plant must be transferred to the stigma of another plant.
After the bee flies off and visits another flower, it goes through a similar ordeal. This time, as it exits the bucket, the pollen packet on its back brushes past the stigma of the new flower, thus achieving pollination.
dwittkower, dogtooth77, Alex Popovkin on Flickr