Underground Flowering Plant: New to Science, Known to Borneo

Scientists have discovered a new species of palm that flowers and fruits underground in Borneo. The plant, named Pinanga subterranea, is the first known member of the palm family to exhibit this rare phenomenon.

What is Pinanga subterranea?

Pinanga subterranea is a palm species that belongs to the genus Pinanga, which comprises about 200 species of palms native to Southeast Asia and the Pacific islands. The species name subterranea comes from the Latin word for “underground”, reflecting its unique habit of producing flowers and fruits below the soil surface.

The plant has a slender stem that can grow up to 2 meters tall, with pinnate leaves that are about 1 meter long. The flowers and fruits are hidden among the exposed roots at the base of the stem. The flowers are small and greenish-white, while the fruits are bright red when ripe and about 2 centimeters in diameter.

The plant is well-known to the indigenous people of Borneo, who call it by various names such as Pinang Tanah, Pinang Pipit, Muring Pelandok, and Tudong Pelandok. They enjoy eating the sweet and juicy fruits, which are also consumed by bearded pigs.

How was it discovered?

The plant was first encountered by Dr Paul Chai, a Malaysian botanist, in 1997 during a visit to Lanjak Entimau Wildlife Sanctuary in Sarawak, Malaysia. He noticed the fruits among the leaf litter surrounding a young palm and collected some specimens for further study.

In 2018, a team of researchers from the Royal Botanic Gardens, Kew, revisited the same site and collected more specimens of the plant. They also found it in Kalimantan, Indonesia, where it was first seen by Agusti Randi, an Indonesian researcher from the National University of Singapore.

The researchers compared the plant with other known species of Pinanga and confirmed that it was a new-to-science species. They published their findings in the journal PALMS and Plants, People, Planet in June 2023.

Why is it so rare?

Flowering and fruiting underground is an extremely rare phenomenon in plants. Most plants have evolved to produce their flowers and fruits above ground to facilitate pollination by insects, birds or wind, and seed dispersal by animals or gravity.

Only a few plant groups have been recorded to flower or fruit underground, such as some orchids, arums and grasses. However, only one other plant is known to do both: Rhizanthella, a genus of small underground orchids from Australia.

The researchers are puzzled by how Pinanga subterranea manages to reproduce successfully underground. They suspect that its flowers are pollinated by some unknown insects that live in the soil, while its fruits are eaten and dispersed by bearded pigs that dig up the roots.

Why is it important?

Pinanga subterranea is an example of the amazing diversity of life on Earth and the secrets that still await discovery. It also highlights the importance of collaborating with indigenous communities and their knowledge of the natural world.

The plant is endemic to Borneo, one of the world’s biodiversity hotspots that is home to many unique and threatened species. However, Borneo’s forests are under pressure from logging, mining, agriculture and development.

The researchers hope that their discovery will raise awareness of the conservation value of Borneo’s underground flora and fauna. They also plan to conduct more studies on the ecology and evolution of Pinanga subterranea and its relatives.