[1] The species was described by Geoff Mansell, owner of Exotica Plants, and Filipino botanist Wally Suarez.

It has so far been recorded with certainty from only two mountains (Mount Hafas & undisclosed location,[1] where it grows in submontane mossy forest at an altitude of up to 1800 m above sea level.

[1] In September 2011 participants on a trip to a remote mountain on south-eastern Mindanao, Stewart McPherson sighted epiphytically growing black Nepenthes truncata-like plants and photos were taken from a distance; it was stated by some of the participants on this same trip that this was evidence of the then newly described N. robcantleyi in habitat.

However, due to the distance and foggy surroundings, no real distinguishing features could be observed in the photo except for superficial similarities to both N. truncata.

At least two commercial horticulturists (such as Geoff Mansell of Exotica Plants) have suggested that nebularum does differ from N. robcantleyi in cultivation and therefore warrants separate species status.