Nepenthes Eymae - Carnivory

Carnivory

Aerial pitchers of N. eymae, with the interior surface clearly visible

Nepenthes eymae produces an extremely thick, mucilaginous pitcher fluid that coats the entire inner surface of the traps in a thin film. This is seen in cultivated plants as well and is most prominent in upper pitchers, which must contend with the action of the wind. These pitchers appear to function at least in part as flypaper traps, with the sticky inner walls trapping small flying insects above the surface of the fluid. The prey then gradually slide down into the base of the pitcher where they are digested. This trapping method was noted by Peter D'Amato in 1993, who observed that, in cultivated plants, lower pitchers were more successful at catching ants than were upper pitchers.

A 2011 study that used cultivated material of N. eymae recorded a mean digestive fluid relaxation time of 0.096 seconds (± 0.000) for this species. As for the majority of studied highland Nepenthes (but not lowlanders), this value differed significantly (P < 0.001) from that of distilled water, leading the authors to categorise N. eymae as a viscoelastic species.

Similarly viscous pitcher fluid is found in the group of closely allied Sumatran species that includes N. aristolochioides, N. dubia, N. flava, N. inermis, N. jacquelineae, N. jamban, N. talangensis, and N. tenuis. These species all share infundibular pitchers.