A remarkable new species of carnivorous plant has been discovered in a remote part of Borneo. It is the first pitcher plant known to produce functional underground traps and the first to capture subterranean prey. While the traps themselves are often a rich maroon color, they are produced on shoots that are completely white due to a lack of chlorophyll.
What we thought we knew about carnivorous plants was quickly called into question after scientists discovered a new species in the Indonesian province of North Kalimantan on the island of Borneo. Nepenthes pudica is classified as a pitcher plant because it has modified leaves that act as pitfall traps or pitchers, allowing it to catch its prey. In a strategy so far unknown from any other species of carnivorous plant with pitfall traps, this one operates underground, catching its prey in the soil.
“We found a pitcher plant which differs markedly from all the other known species,” says Martin Dančák of Palacký University in Olomouc, the Czech Republic, lead author of the study, published in the journal PhytoKeys, where his team described the new species.
“In fact, this species places its up-to-11-cm-long pitchers underground, where they are formed in cavities or directly in the soil and trap animals living underground, usually ants, mites, and beetles,” he adds.
We found a pitcher plant that differs markedly from all the other known species. In fact, this species places its up-to-11-cm-long pitchers underground, where they are formed in cavities or directly in the soil and trap animals living underground, usually ants, mites, and beetles.
Martin Dančák
Only three other groups of carnivorous plants are known to trap underground prey, but they all use very different trapping mechanisms and can only catch minuscule organisms, unlike Nepenthes pudica.
The plant grows specialized underground shoots with chlorophyll-free, white leaves. The leaves that support the pitchers are reduced to a fraction of their normal size and lack their normal green pigmentation. The pitchers, on the other hand, retain their size and, in some cases, their reddish color.
“Interestingly, we found numerous organisms living inside the pitchers, including mosquito larvae, nematodes and a species of worm which was also described as a new species,” explains Václav Čermák of the Mendel University in Brno, Czech Republic, who was also part of the research team.
The newly discovered species grows on relatively dry ridge tops between 1100 and 1300 meters in elevation. This could be why it evolved to move its traps underground, according to its discoverers. “We hypothesize that underground cavities have more stable environmental conditions, including humidity, and that there is presumably more potential prey during dry periods,” says Michal Golos of the University of Bristol, UK, who also worked on this unusual plant.
A series of lucky events back in 2012 led to the discovery of the species. Ľuboš Majeský of Palacký University Olomouc, part of the research team, recounts the key moment: “During a several-day trip with our Indonesian colleagues to a previously unexplored mountain, randomly chosen from a number of candidates, we noted plants which were undoubtedly Nepenthes but produced no pitchers. After a careful search, we found a couple of aerial pitchers, a few juvenile terrestrial ones, and one deformed pitcher protruding from the soil.”
“We initially assumed it was an unintentionally buried pitcher and that the lack of other pitchers was due to local environmental conditions. Still, as we discovered more pitcherless plants on our way to the summit, we wondered if a pitcher plant species had evolved to lose carnivory, as seen in other carnivorous plants. But then, while photographing, I tore a moss cushion from the base of a tree, revealing a swarm of richly maroon-colored pitchers growing from a short shoot with reduced leaves devoid of chlorophyll.”
The group then examined the other plants they encountered and discovered that they all had underground shoots with pitchers, confirming that this species prefers the underground environment.
The plant’s scientific name, Nepenthes pudica, refers to its peculiar behavior: it is derived from the Latin adjective pudicus, which means bashful and refers to the fact that its lower pitchers are hidden from view.
Borneo is home to the endemic Nepenthes pudica. “This discovery is significant for nature conservation in Indonesian Borneo because it highlights the island’s importance as a global biodiversity hotspot. We hope that the discovery of this unusual carnivorous plant will aid in the protection of Bornean rainforests, particularly by preventing or slowing the conversion of pristine forests into oil palm plantations “Wewin Tjiasmanto of Yayasan Konservasi Biota Lahan Basah, who assisted in the discovery of the new species, concludes.
