Nepenthes talangensis /nɪˈpɛnθiːz ˌtɑːlɑːŋˈɛnsɪs/ is a tropical pitcher plant endemic to Sumatra, where it grows in upper montane forest at elevations of 1800–2500 m above sea level.

[8] Two early colour photographs of N. talangensis were published by Mike Hopkins, Ricky Maulder, and Bruce Salmon, in a 1990 issue of the Carnivorous Plant Newsletter,[5] where the species was again confused with, and identified as, N. bongso.

[2] Nerz's field studies, coupled with observations of N. bongso made by Mr. and Mrs. DeWitte on Mount Singgalang in 1993, showed that the two taxa almost certainly represented distinct species.

[2] This research culminated in the formal description of N. talangensis by Nerz and Wistuba in the December 1994 issue of the Carnivorous Plant Newsletter.

[2] Matthew Jebb and Martin Cheek synonymised N. talangensis with N. bongso in their 1997 monograph, "A skeletal revision of Nepenthes (Nepenthaceae)".

[8] The next detailed treatment of N. talangensis appeared in Stewart McPherson's 2009 monograph, Pitcher Plants of the Old World, which retained it as a separate species.

[8][9] The discovery of a new population of apparently tetraploid N. talangensis was reported by Kazuhisa Mio in the July 2006 issue of the Journal of Insectivorous Plant Society.

[12] Nepenthes talangensis was used in a 2009 study on the effect of prey capture on photosynthetic efficiency, published in the journal Annals of Botany.

[9] The pitcher mouth is round and positioned horizontally in the front two-thirds, rising at the rear to form a short neck.

The peristome is generally yellow or orange in freshly opened traps, later becoming dark red to purple as the pitcher matures.

The upper surface of the lid is often yellow with orange to purple blotches, whereas the underside may be completely red, although this is not always the case.

It may grow in shady conditions under dense tree cover or among open, stunted shrubs where it is exposed to strong or even direct sunlight.

[1] This agrees with an informal assessment made by Charles Clarke in 2001, who also classified the species as Endangered based on the IUCN criteria.

[9] A substantial number of plants persist on Mount Talang despite its recent volcanic activity, which has included large eruptions.

Due to its status as an active volcano, Mount Talang receives few visitors and is not a major target for development.

[9] Nepenthes talangensis produces extremely thick, mucilaginous pitcher liquid, which coats the entire inner surfaces of the traps in a thin film.

[9] Similarly viscous pitcher fluid is also found in seven other closely allied Sumatran species: N. aristolochioides, N. dubia, N. flava, N. inermis, N. jacquelineae, N. jamban, and N. tenuis.

[9] Despite being confused with N. bongso throughout much of its botanical history, N. talangensis is clearly distinct from this species and can easily be distinguished on the basis of its greatly incurved peristome and smaller laminae with hair-fringed margins.

[8] The funnel-shaped upper pitchers of N. talangensis may also be reminiscent of species such as N. eymae, N. flava, N. inermis, N. pitopangii, and N. tenuis.

However, N. talangensis differs from all of these in its combination of a wide lid without appendages and a greatly incurved peristome bearing conspicuous ribs and teeth.

[9] Nepenthes aristolochioides is thought to be the closest relative of N. talangensis[8] and these two species share a very similar lamina structure.

[8][9] Nepenthes inermis is known to hybridise with N. talangensis on the upper slopes of Mount Talang, where the two species grow sympatrically.

In a 1973 article on the Nepenthes of Borneo, Singapore, and Sumatra,[4] Shigeo Kurata incorrectly identified specimens of this hybrid as belonging to N. dubia.

[8] In 1997, Matthew Jebb and Martin Cheek published their monograph "A skeletal revision of Nepenthes (Nepenthaceae)", in which they referred to N. dubia plant material from Mount Talang (Kurata s.n.

Clarke found that the type specimen of N. pyriformis, Kurata & Mikil 4230 NDC, matches the appearance of N. inermis × N. talangensis "in most respects".