Pinanga Subterranea: New Species of Rare Palm Discovered to Flower Underground

Flowers are usually associated with happiness, beauty, and other symbolic meanings. As an important part of a plant, flowers serve as the reproductive organs which allow pollination to develop fertilized embryos in the form of fruit.

The most common illustrations people have about flowers are those found coming out from the stem of the plant and blooming for the observer to see. However, an international team of scientists discovered a plant that hides its flower and fruit in plain sight.

An Unusual Palm Species

The island of Borneo in Southeast Asia is home to a rare palm species which produces its flowers and fruits almost entirely underground. The unusual palm is popular with locals who eat its bright-red fruit as a sweet and juicy treat. To date, there are nearly 300 various species of palm discovered on the tropical island.

Due to its strange characteristics, the plant was named Pinanga subterranea, with its species name taken from the Latin word, which means underground. Pinanga subterranea is part of 2,500 species of palm known by the scientific community, half of which face the threat of extinction.

Before it was studied scientifically, the plant was identified in three Bornean languages: Pinang Pipit, Pinang Tanah, Tudong Pelandok, and Muring Pelandok. Experts suggest that the plant might be scattered across the rainforests in the western part of Borneo, even crossing the boundaries from Malaysia to Indonesia.

Uncovering the Hidden Beauty

Although Pinanga subterranea is popular among the indigenous people in Borneo, it caught the attention of the scientific community just recently. Scientists from Royal Botanic Gardens, Kew in Richmond, England, investigated this plant after they were alerted by Malaysian botanist and study co-author Dr. Paul Chai. He first encountered the plant in 1997 when he visited the Lanjak Entimau Wildlife Sanctuary in Sarawak, Malaysia.

In 2018, scientists Benedikt Kuhnhäuser, Peter Petoe, and William Baker revisited the sanctuary and gathered palm samples for scientific studies.

The research team must still demonstrate Pinanga subterranea's novelty, even with Dr. Chai's tip-off. Over 140 palm species in Pinanga are known, mostly small and erect. Almost 100 of these species thrive in Southeast Asia, where Borneo is the center of their diversity.

To discern this plant as a novelty, the scientists need insight from the meticulous investigation of Indonesian researcher and lead author Agusti Randi. He made comparisons of this palm species with all the other known Bornean species of Pinanga.

Despite the dual nature of geocarpy and geology associated with Pinanga subterranea, scientists were able to observe a lot of seeds and fruits set by this plant in their habitat, which suggests that they have pollinated successfully.

On the other hand, the researchers also figured out the plant's mechanism in dispersing the seeds through the rainforest. It was found that the fruits are dug up and eaten by the bearded pig in search of food using its fine sense of smell. As the fruits are consumed, their seeds are released in the pig's feces and dispersed in the ground.