[4][5] Forest fires destroyed the only known population of N. campanulata in 1983 and it was uncertain whether the species had survived elsewhere or was in fact extinct.

'Doc' Kostermans, the head of the Botanical Division of the Forestry Research Institute at Bogor, on the same expedition in which he collected the type material of N. mapuluensis.

Kostermans wrote the following account of his discovery:[3] I was working for the Forestry Department at that time in Sangkulirang and when I had finished I wanted to find out about a flowering rock, Ilas Bungaan,[note b] upriver.

When we were there we discovered that the yellow colour was that of the leaves of a Nepenthes completely covering the steep face of the 50 m high rock.

The Nepenthes was not in flower or fruit, but we found caves in the rock and in the caves a couple of boat-like coffins with sculptured dog-head ends which contained decapitated skeletons.Nepenthes campanulata was described by Shigeo Kurata in 1973 based on a single specimen, Kostermans 13764, deposited at the herbarium of the Singapore Botanic Gardens.

[8][9] According to Kurata, the collector stated that the species was endemic to this single location "presumably owing to its habitat which is noted as sand and limestone walls at an altitude of 300 m".

Nepenthes campanulata produces short, cylindrical, climbing stems 20 to 50 cm tall[2] and up to 4 mm thick.

However, the species was rediscovered in 1997 by Ch'ien Lee on the limestone cliffs of Gunung Mulu National Park in Sarawak, more than 400 km from the type locality.

[1][13][14][15][16] In July 2013, a taxon closely resembling N. campanulata was observed and photographed growing on the limestone cliffs of the Saint Paul formation, Palawan, the Philippines.

[6] 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.[6][17]