[3][7] The site was reached by a small stream and lay around 2 miles (3.2 km) from the Kedayan settlement of Meringit, located at the head of the Meropok branch of the Lawas River in Sarawak, Borneo.

[1] Macfarlane noted its similarity to N. rafflesiana but distinguished it on the basis of "the nerves of the leaves, the long and slender tendril, the slim and elongated pitchers, the heart-shaped lid with diffused glands, the deep off-leading surface" (translated from the original Latin).

[7] Twenty years later, B. H. Danser sunk N. hemsleyana in synonymy with N. rafflesiana in his "The Nepenthaceae of the Netherlands Indies",[9] having apparently not examined the type material of the former.

[2] In 2013, Mathias Scharmann and T. Ulmar Grafe pointed out that this taxon had already been formally described more than 100 years earlier, as N. hemsleyana, and that this is therefore the correct name under the botanical rules of priority.

It frequently bears multicellular, filiform appendages on the upper surface of the lid, similar to those of the N. tentaculata group of species; these have never been documented in N. rafflesiana.

[7] The species may still be extant near its type locality in Lawas District, Sarawak, but much of the area's original forest has been destroyed since Burbidge's time and replaced by oil palm plantations.

The former cross differs from sympatric N. × hookeriana (N. ampullaria × N. rafflesiana) in possessing a waxy zone, a narrower peristome, and hairs on the upper surface of the lid.

[2][15][16][17][18] This relationship appears to be mutualistic, with the plant providing shelter for the bats and in return receiving additional nitrogen input in the form of faeces.

This structure shows far stronger echo-reflection than a comparable area in the most closely related pitcher plant species, Nepenthes rafflesiana.