Carnivorous pitcher plants are pretty badass as botanical beasts go (some eat salamanders, 'nuff said), and they just got a whole lot more metal as for the first time scientists have uncovered a nepenthes species that feasts underground. The subterranean predator was found in North Kalimantan, Indonesia, where it catches ants and other insects in pitchers that grow in soil cavities.
The first-of-its-kind species has been described in PhytoKeys and named Nepenthes pudica by the team who traveled to North Kalimantan’s montane rainforest back in 2012. Here, they discovered that beneath the surface of the earth, N. pudica was employing a trapping strategy never before seen in carnivorous plants.
Trapping living prey underground isn’t unheard of among the leafy meat-eaters, but other plants that do this use different trap styles, such as Utricularia’s sucking utricles, to the sticky leaves of Philcoxia and the lobster-pot approach of Genlisea. Instead, N. pudica grows well-developed, fully-functional pitcher traps
The traps grow almost exclusively on N. pudica’s underground basal shoots and measure around 7–11 centimeters high and 3–5.5 centimeters wide. A small meal for a human, but that’s plenty of space for cooking up some ant beetle broth.
The carnivore appears to favor trees whose branch roots have formed cavities that are topped with a moss layer, creating plenty of space for them to unfurl their predatory pitchers. If space is in short supply, N. pudica will also grow pitchers in soil or under moss cushions.
When they looked at other Nepenthes species in the area, they discovered that N. pudica was the only plant sprouting pitchers underground. This is interesting, as it demonstrates that the trait isn’t simply a result of the plant’s environment but seemingly an adaptive behavior evolved by this species specifically.
“The underground shoots of N. pudica had no obstacles preventing them from growing upwards,” wrote the study authors. “Neither did they show signs of growing towards light, even when concealed only under a soft moss cushion.”
Beyond enticing options for a film sequel Little Shop of Horrors: This Time It’s Earthy, the discovery of a novel feeding strategy among carnivorous plants in Borneo demonstrates the scientific value of the region, say the researchers, and the necessity to protect it.
“Nepenthes pudica is known only from a few neighbouring localities in the Mentarang Hulu district of North Kalimantan, where it grows on ridgetops at an elevation of 1100–1300 [meters],” they wrote. “Its discovery underlines the natural richness of Borneo’s rainforest and the necessity to preserve this important ecosystem with its enormous and still undiscovered biodiversity.”
