New Species of Orangutan-Colored Pitcher Plant Discovered in Mountains of Borneo

In the ultramafic mountains of central Sabah, Borneo, grow “giant pitcher” plants. They are characterized by their large, bell-shaped lower and upper pitchers and upright, narrow lids. The plant uses its pitchers to capture rainfall and insects.

A team of botanists from Sabah Forestry Department’s Forest Research Centre in Malaysia — along with two colleagues from Australia — has identified a new species of these distinctive plants that is the color of orangutans who live in the area, reported Phys.org.

“One of the largest species of Nepenthes described in recent years, N. pongoides is endemic to the relatively low-elevation ultramafic Meliau Range of central Sabah. Only 39 mature individuals have been observed across two subpopulations, therefore the species is here assessed as CR (Critically Endangered) under the IUCN Red List criteria owing to its extremely small population size, limited area of occurrence and very high threat of unsustainable poaching for the horticultural trade,” the research team wrote in their paper on the discovery.

In “Sabah’s hidden giant: Nepenthes pongoides (Nepenthaceae), a micro-endemic tropical pitcher plant from northern Borneo,” the team describes how they became familiar with the plant and what their expedition to the site revealed.

The researchers examined reports of an unknown Sabah mountains pitcher plant that was photographed in 2004, but had never been investigated, Phys.org reported. News of scientists having taken additional photographs in 2018 prompted members of the team to travel to the site to take a look.

On the third day after they arrived in the region, the research team found what they were searching for: a mound of igneous bounders. The area seemed suitable for a rainwater capturing plant, since there was no running water in the vicinity.

“An expedition was made to the type locality to make field observations of the taxon, record habitat, population and ecological data such as infauna, prey spectra and numbers of individuals, and to collect representative vouchers, minimising negative impacts on the small population by taking material in the form of terminal cuttings to allow for the in situ regeneration of sampled individuals from axillary nodes,” the researchers wrote in their paper.

Pitchers and habit of Nepenthes pongoides. (a) Rosette pitcher of immature plant showing highly developed peristome column. (b) Pendent pitcher of a scrambling plant. Note ventral attachment of tendril and scattered large nectar glands of same. (c) Large terrestrial pitcher. (d) Mature rosette emergent from humus-filled fissure between ultramafic boulders; a cutting from this rosette was sampled as voucher 161456. (e) An individual demonstrating occasionally observed scrambling habit. Photographs (a), (e) by A. Damit; (b), (c), (d) by A.S. Robinson. Australian Journal of Botany (2024). DOI: 10.1071 / BT24050

The team noted that the leaves of the plant were unique and that there was long red hair covering the pitcher that was almost the same color as that of the orangutans who live in the area, leading them to name the novel species Nepenthes pongoides, or “resembling orangutan.”

After subsequent research, the team discovered that the plant was the largest pitcher that had ever been identified.

“Nepenthes pongoides is described and illustrated as new to science. The species is characterised by its large size, peltate tendril exsertion, absence of upper pitchers and extremely well-developed, persistent indumentum of long, coarse, dark reddish trichomes, the extent of which is unsurpassed in any other known Bornean Nepenthes species,” the researchers wrote.

The team made two expeditions to the same region, during which they learned not only of the plant’s uniqueness, but also of its vulnerability, noting that poachers had already heard about the findings and had been harvesting the giant pitchers.

In addition to poaching, the rare plants are also susceptible to natural threats.

“As is the case for many microendemic species, the taxon is extremely vulnerable to stochastic events such as fire which, on sufficient scale, could represent extinction level events,” the researchers warned.

A member of the Nepenthes genus — which consists of over 160 species — the newest species of pitcher plant can grow as large as 45 centimeters and hold more than two liters of water.

“The documentation of such remarkable new species in comparatively well-explored rainforest regions such as those of northern Borneo highlights the importance of targeted exploration in remaining wilderness areas to uncover hidden biodiversity. Doing so closes gaps in scientific knowledge, and specifically increases the critical taxonomic and ecological knowledge necessary to support the development and implementation of conservation measures required to reduce the risk of species extinction and concomitant loss of biodiversity,” the researchers wrote in the paper.