A pitcher plant discovered in a rainforest in Borneo uses underground traps grown under a moss mat (left) and in a cavity under tree roots (right) to catch prey.

Scientists didn’t expect the eggplant-shaped pitchers to be subterranean survivors

Biologist Martin Dančák didn’t set out to find a plant species new to science. But on a hike through a rainforest in Borneo, he and colleagues stumbled on a subterranean surprise.

Hidden beneath the soil and inside dark, mossy pockets below tree roots, carnivorous pitcher plants dangled their deathtraps underground. The pitchers can look like hollow eggplants and probably lure unsuspecting prey into their sewer hole-like traps. Once an ant or a beetle steps in, the insect falls to its death, drowning in a stew of digestive juices (SN: 11/22/16). Until now, scientists had never observed pitcher plants with traps almost exclusively entombed in earth.

“We were, of course, astonished as nobody would expect that a pitcher plant with underground traps could exist,” says Dančák, of Palacký University in Olomouc, Czech Republic.

That’s because pitchers tend to be fragile. But the new species’ hidden traps have fleshy walls that may help them push against soil as they grow underground, Dančák and colleagues report June 23 in PhytoKeys. Because the buried pitchers stay concealed from sight, the team named the species Nepenthes pudica, a nod to the Latin word for bashful.

The work “highlights how much biodiversity still exists that we haven’t fully discovered,” says Leonora Bittleston, a biologist at Boise State University in Idaho who was not involved with the study. It’s possible that other pitcher plant species may have traps lurking underground and scientists just haven’t noticed yet, she says. “I think a lot of people don’t really dig down.”

Citations

M. Dančák et al. First record of functional underground traps in a pitcher plant: Nepenthes pudica (Nepenthaceae), a new species from North Kalimantan, Borneo. PhytoKeys. Published online June 23, 2022. doi: 10.3897/phytokeys.201.82872.