Cephalotus follicularis - Pitfall trap
Cephalotus allures the prey primarily by fragrant nectaries. There are small nectaries all over the pitcher. They are most abundant on the teeth of the peristome and on the lower side of the lid. Furthermore, colors and hairs also function as a lure. The bright translucent drawings on the lid is a kind of fenestration with a similar function as in Darlingtonia. The wings are interpreted as outgrowths from the leaf lamina. The frontal (middle) wing is forked so it forms a Y in cross section. It is not proven if the wings function as a guide track (ant track) for small insects as it is the case in Sarracenia. Young pitchers are green but the more sun they receive, the redder they become with time. Hairs and dark red colors seem particularly appealing on several species of flies but there are no investigations showing if it is beneficial for Cephalotus. Most crawling animals are caught such as ants. It is unclear, how much the photosynthesis in the pitchers contributes to the growth of the plant.
The lid has a certain umbrella effect against flooding of the pitcher with rain but it does not prevent some rain from entering the pitcher. The pitchers in nature are said to always contain fluid, so it is supposed that the main fluid volume is produced by the pitcher itself. If the juice tension (water potential) decreases in the pitcher following water stress, the lid will fall towards the peristome and thereby evaporation from the pitcher fluid is reduced.
H. S. Heide-Jørgensen, april 2014, translated May 2021.