A New Botanical Discovery in Tapanuli: The 'Cat's Tongue' Plant Homalomena lingua-felis and Its Unique Morphology

The Indonesian National Research and Innovation Agency (BRIN) has formally announced the identification of a new plant species native to the Tapanuli region of North Sumatra. Scientifically designated as Homalomena lingua-felis, this botanical find highlights the rich endemic flora found within the Indonesian archipelago. The formal recognition marks a significant addition to the country's documented natural heritage and underscores the importance of ongoing biological surveys.

This discovery stems from a field expedition conducted in the Batang Toru district during January 2024. The comprehensive taxonomic description of the species was later detailed and published in the international scientific journal PhytoKeys in March 2026. The plant's Latin name, which translates to 'cat's tongue,' was chosen to reflect a striking morphological trait: the upper surface of its leaves is densely covered in fine hairs, creating a texture reminiscent of a feline's tongue. This research was spearheaded by Muhammad Rifki Hariri of BRIN, working alongside a multi-institutional team from the Herbarium Bandungense SITH ITB, Sebelas Maret University, IPB University, Lampung University, the Indonesian Tropical Botany Foundation, and the Jungle Farm Nursery.

Following an initial assessment based on the International Union for Conservation of Nature (IUCN) criteria, Homalomena lingua-felis has been classified as 'Vulnerable' (VU). This precarious status is attributed to its extremely localized distribution and the mounting anthropogenic pressures it faces, such as illegal plant collection and widespread deforestation. While Sumatra is a known center of diversity for the Homalomena genus—boasting 41 distinct species—this particular plant is at high risk due to its specialized habitat. It thrives exclusively on rocky cliff faces near waterfalls at elevations ranging from 15 to 50 meters above sea level, environments that are increasingly susceptible to degradation.

To distinguish Homalomena lingua-felis from its relatives, researchers performed a meticulous comparison with the closely allied species Homalomena pexa. The study revealed definitive morphological and genetic variances that justify its classification as a separate species. Notable physical differences include:

• A significantly shorter petiole, measuring between 2.0 and 4.5 cm, compared to the 7.0 to 12 cm found in H. pexa.
• A papillose texture on both the petiole and the underside of the leaf.
• A distinct cone-shaped zone within the male flowers.

Beyond its botanical significance, the discovery underscores the urgent need to protect the ecosystems of North Sumatra. The Batang Toru region, where the plant was found, represents one of the final frontiers of primary tropical rainforest on the island. However, this area is under intense pressure from industrial expansion, including large-scale hydroelectric projects. According to data provided by Greenpeace, the Batang Toru catchment area suffered a loss of 70,000 hectares of forest between 1990 and 2022, representing approximately 21 percent of its total landmass. In response to these environmental challenges, Indonesian authorities are currently investigating 12 legal entities suspected of contributing to forest destruction in areas adjacent to the new species' habitat.

The successful identification of H. lingua-felis by a collaborative group of scientists from BRIN and various Indonesian academic institutions reinforces the nation's standing as a global epicenter of biodiversity. This find serves as a reminder that many unique species remain to be discovered, provided their habitats can be shielded from further encroachment. The ongoing efforts of the scientific community remain vital in documenting and advocating for the preservation of Indonesia's irreplaceable natural resources, ensuring that such unique biological treasures do not vanish before they are even named.