Darlingtonia - catching method
Darlingtonia primarily allures the prey by scent from the nectaries placed over large parts of the pitcher both outside and inside but with the majority located on the recurved pitcher edge and on the lid formed as a fish tail. The whitish spots on the dome-shaped upper part of the pitcher and the red meat-color on the fish tail and the network of the vascular bundles are attractive to certain fly species. If the plant gets full sunshine the red color often becomes more dominant than shown on the pictures. The two photos on the left are from plants in a greenhouse.
Seen through the mouth the light spots called fenestrations are glass clear because the cells are very thin-walled and only contain water in the large central vacuole which occupy the whole cell. A potential prey perceives the light incidence through the fenestrations as a sign of free passage, and it therefore takes off from the fish tail or the pitcher edge and flies through the mouth, where it hits the inner wall of the dome and falls to the bottom of the pitcher only to drown in the pitcher fluid.
The pictures also illustrate the twisting of the pitcher.
—– H. S. Heide-Jørgensen, February 2022.