Nepenthes Adnata - Related Species

Related Species

Nepenthes adnata has no obvious close relatives within the genus. Rusjdi Tamin and Mitsuru Hotta considered the species to be closely related to N. tentaculata, N. gracillima, and N. gracilis. Both Jan Schlauer and Joachim Nerz as well as Matthew Jebb and Martin Cheek agreed that N. adnata and N. tentaculata are related, while J. H. Adam, C. C. Wilcock and M. D. Swaine considered the two taxa conspecific. However, Charles Clarke does not support this interpretation, stating that the similarities between the two species are probably coincidental and that the closest relatives of N. adnata "are more likely to be other Sumatran species such as N. gymnamphora, N. longifolia or N. albomarginata". Clarke points out that the multicellular hairs sometimes exhibited by N.adnata, which several authors have used to suggest a relationship with N. tentaculata, occur in rosette pitchers of many other species, especially N. rafflesiana.

The pitchers of N. adnata are similar to those of N. tobaica, although the stem and lamina are quite different. They also bear a superficial resemblance to those of a form of N. gymnamphora from Mount Sorik Merapi. Seedlings of N. adnata and N. longifolia are virtually indistinguishable, although mature plants have few morphological features in common. N. adnata also shares with N. albomarginata a similar indumentum and ecology.

In 2001, Clarke performed a cladistic analysis of the Nepenthes species of Sumatra and Peninsular Malaysia using 70 morphological characteristics of each taxon. The following is a portion of the resultant cladogram, showing "Clade 6", which is only weakly supported at 50%. The sister pair of N. angasanensis and N. mikei has 79% support.