Taxonomy
In his description of N. campanulata, Kurata suggested that it may be closely related to N. inermis, a Sumatran endemic. However, other taxonomists disagree with this hypothesis. These two species are similar in general stature as well as pitcher morphology. However, they are not only separated by great geographical distance, but also occur in completely different habitats; N. campanulata is a lowland species endemic to limestone substrates, whereas N. inermis usually grows as an epiphyte at elevations of 1500 to 2600 m.
Read more about this topic: Nepenthes Campanulata