Cephalotus follicularis -The pitcher collar
The inside of the Cephalotus pitcher is like the other pitfall traps divided into zones to prevent prey from crawling out of the trap. From the pitcher edge and the underside of the peristome teeth to about midway down the pitcher all epidermal cells have grown into pointed hairs (trichom). About a fourth from the pitcher mouth the trap is equipped with a downward directed circular collar (or roof beard), where the trichome tips, independently of the curving of the collar, are pointing downwards. The trichomes increase in length towards the middle of the collar. The hair zone is replaced downwards by a plane and smooth gliding zone, which according to literature is supplied with numerous small glands of unknown function. Then follows the two dark gland patches with digestive glands and a smooth bottom zone without glands (see here).
At left and above trichomes are seen from the inside of the collar. At right somewhat shorter trichomes appear from the area above the collar and closer to the peristome. The trichomes are living cells but it is unknown if they have a function besides the fact that they together with the teeth, collar, and gliding zone help direct the prey into the trap and prevent it from escaping.
At left trichomes are shown from the hollowing under the collar, and at right hairs from the outside of the collar are shown. A strongly folded cuticle patterns the surface of the trichomes.
The photo at left is from the same area as the photo just above but the trichomes are seen from the tips. It is clear that the basal part of the trichomes are interconnected by a thin cuticle covered cell wall. At right, short trichomes are shown from the area just above the transition to the smooth gliding zone. Some bacteria are present in the pits between the hairs, which makes it probable that this part has been covered by pitcher fluid.
The pictures below is from the transmission electron microscope. Cell nucleus, cuticle folds and cell wall bridges are seen. It is a mystery what the purpose is of these folds and bridges.