By Darren Incorvaia

    Palm trees are often associated with Hollywood Boulevard and tropical resorts, but their relatives in the palm family Arecaceae can come in many different shapes and sizes. And one shuns the limelight to an almost absurd degree — the new-to-science Pinanga subterranea palm grows its flowers and fruit entirely underground.

    “We knew immediately that it’s a really odd palm,” says Benedikt Kuhnhäuser, a botanist at Royal Botanic Gardens, Kew, in Richmond, England.

    Malaysian botanist Paul Chai first noticed the palm growing in Lanjak Entimau Wildlife Sanctuary, on the island of Borneo, in the late 1990s. However, Kuhnhäuser says, Chai lost all his photographic evidence for the enigmatic plant during flooding in Kuching, the capital of the Malaysian state of Sarawak. In 2018, Chai told Kuhnhäuser and other botanists visiting Borneo about the lost palm over breakfast. The team embarked on a multiday trek to reach the sanctuary and found, to their surprise, that the underground palm was actually abundant.

    Growing anything other than roots underground is rare, but examples can be found across the plant kingdom. South-central Africa is home to an “underground forest” where many plants flower aboveground but grow woody material below; a Bornean pitcher plant buries its traps under the soil (SN: 7/8/22). In fact, plants across 33 different families have been found to conceal flowers or fruits underground, but burying both is exceedingly rare. Besides the underground palm, “there’s only one other plant in the world that does this,” Kuhnhäuser says, “and that’s some tiny orchid genus called Rhizanthella in Australia.”

    Just because the palm is new to science doesn’t mean no one knew it existed. “Several local people, especially Indigenous ones, knew the palm,” says Cibele de Cássia Silva, a botanist at the University of Campinas in Brazil who was not involved with the research. The local people not only had names for it, but some dig up and eat the inconspicuous palm’s fruit as a snack. For Cássia Silva and Kuhnhäuser, this highlights the importance of not only engaging with Indigenous knowledge but also including that knowledge in scientific papers.