Nepenthes macrophylla /nɪˈpɛnθiːz ˌmækroʊˈfɪlə/, the large-leaved pitcher-plant,[4] is a tropical pitcher plant known only from a very restrictive elevation on Mount Trusmadi in Sabah, Malaysian Borneo.

Nepenthes macrophylla was once thought to be a subspecies of N. edwardsiana, but differs from that species in several aspects of pitcher and leaf morphology.

[5] Nepenthes macrophylla was known to grow on Mount Trusmadi for a long time prior to its description, although it was not initially considered a distinct species.

Though this information is not confirmed yet, its existence is expected because this mountain falls within the vertical distribution of this species.Later, N. macrophylla was treated as a form of N. edwardsiana, another closely related species.

[4] Botanists Matthew Jebb and Martin Cheek had intended to elevate N. macrophylla to species status since at least 1994[10] and did so upon the publication of their 1997 monograph "A skeletal revision of Nepenthes (Nepenthaceae)" in the botanical journal Blumea.

It is canaliculate (grooved lengthwise) and typically bears wings that form a partially amplexicaul sheath around the stem.

[11] Older sources list a number of different values for the altitudinal distribution of N. macrophylla, with some giving a narrow range of 2200–2400 m[5] and others a much wider span of 2000–2600 m.[1][2] It is now known that this species occurs between 2200 m and the summit at 2642 m.[11][12] The typical habitat of N. macrophylla is mossy montane forest along ridge tops, where the vegetation is dominated by Leptospermum and Rhododendron.

[13] Like most highland Nepenthes species, N. macrophylla experiences marked temperature fluctuations between day and night, from a noon maximum of around 30 °C to a nighttime minimum of 5 °C.

[7] Relative humidity is always high and in the late evening the summit of Mount Trusmadi is often shrouded in mist and clouds.

[1] This differs slightly from an informal assessment made by botanist Charles Clarke in 1997, who classified the species as Endangered based on the IUCN criteria.

[14] A 2010 study showed that the shape and size of the pitcher orifice of N. macrophylla exactly match the dimensions of a typical Tupaia montana.

[14][16][17][18][19] In all three of these species (N. ephippiata has not been investigated), the colour of the lower lid surface corresponds to T. montana visual sensitivity maxima in the green and blue wavebands, making it stand out against adjacent parts of the pitcher.

Although highly developed, the peristome ribs and teeth of N. macrophylla are considerably shorter and more widely spaced than those of either N. edwardsiana or N. villosa.

[8] The pitcher mouth of N. macrophylla is distinctive in that it rises gradually towards the lid, while at the same time not forming a pronounced neck.

[4] Whereas N. edwardsiana and N. villosa are restricted to generally ultramafic soils in the Kinabalu area, N. macrophylla is only found near the summit of Mount Trusmadi, which is mostly composed of sandstone.

[5][8] Botanists Matthew Jebb and Martin Cheek suggest that N. macrophylla is related to N. mira, a species endemic to Palawan in the Philippines.

[5] Nepenthes × trusmadiensis is restricted to the summit ridge of Mount Trusmadi and has been recorded from elevations of 2500 to 2600 m above sea level.