In 2023, the botanical world was stunned by the discovery of Pinanga subterranea, an extraordinary palm species from the rainforests of Borneo.
This palm attracted significant attention from scientists due to its rare ability: the entire reproductive process—from flowering to fruiting—occurs entirely underground.
The species was officially described by a collaborative team of researchers from Herbarium Bogoriense (Indonesia), the Royal Botanic Gardens Kew (UK), and the University of Zurich (Switzerland), with involvement from local communities in the West Kalimantan, Indonesia and Sarawak, Malaysia.
Underground Flowering and Fruiting
Pinanga subterranea exhibits two remarkable traits: geoflory (flowering underground) and geocarpic (fruiting underground). No part of the flower or fruit emerges above the surface. When the fruit ripens, it turns bright red but remains hidden beneath the soil.
A study first published in the PALMS Journal titled "Pinanga subterranea, a New Arecoid Palm from Borneo that Flowers Underground" highlighted that this is the first instance in the palm family (Arecaceae) to show such a reproductive ability.
Underground reproduction is typically found in only a few species from non-palm plant families, making this discovery a groundbreaking advancement in the study of tropical plant morphology and evolution.
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Ecological Niche of Pinanga Subterranea in Borneo
This palm species naturally grows in the lowland rainforests of Borneo, particularly in areas with clay, limestone sand, or red soil that have high moisture levels. Its growth is recorded at elevations ranging from 100 to 650 meters above sea level.
The plant appears inconspicuous due to its short stem, which is often buried underground. However, its leaves rise upward, consisting of 4 to 6 fronds, each about 25-85 centimeters long.
A Natural 'Partnership' with Borneo's Bearded Pigs
In the Bornean rainforest ecosystem, Pinanga subterranea has an intriguing symbiotic relationship with wildlife, particularly the Bornean bearded pigs (Sus barbatus). These animals are known to dig the soil in search of the palm's fruits, making it a natural part of their diet.
Once consumed, the palm seeds are dispersed through the pigs' feces, which helps to naturally expand the distribution of the species within the forest.
A study published in Plants, People, Planet titled "Hiding in Plain Sight: The Underground Palm Pinanga Subterranea" also mentions that this strategy represents an efficient ecological adaptation to the closed, humid, and low-light environment of the tropical forest floor.
Indigenous Insights and Scientific Discovery
Interestingly, although it was only recently documented scientifically, indigenous communities in Borneo have long been aware of the existence and benefits of this underground palm. In Kalimantan, it is known as "pinang tanah" or "muring pelandok," and its fruit is often consumed as a natural forest snack.
An investigative article published by The Guardian in mid-2023 highlighted that the successful scientific identification of Pinanga subterranea heavily relied on the ecological knowledge of local communities, who had understood the plant’s life cycle long before it was formally recognized by Western science.
