The postal authority of Madagascar released a set of floral stamps on August 6, 1973. Two stamps (denominations 25f and 40f) have image of pitcher plant (same species). The pitcher plant species depicted on the stamps should be
Nepenthes madagascariensis. However, the species inscription on the stamps is
Nepenthes pervillei. So, it is a misidentification of the pitcher plant species.
Nepenthes pervillei is endemic to Seychelles Island while
N. madagascariensis is endemic to Madagascar Island. These two species are easily distinguished by the shape of pitcher. Actually,
N. madagascariensis is the first
Nepenthes species to be discovered (in 1685). It is distributed along the eastern coast of Madagascar.

the pitcher plant species on the stamps is Nepenthes madagascariensis not Nepenthes pervillei