Rare Earth Mango Fungus Rediscovered in Kerala: Insights into Subterranean Biodiversity

The Serendipitous Rediscovery of Nilamanga in Kerala's Soil

In the quiet village of Karakurussi in Palakkad district, Kerala, a farmer's routine land preparation for cultivation unearthed something extraordinary. While digging, Govindanunni stumbled upon around twenty peculiar underground structures resembling small mangoes on stalks. These were no ordinary roots or tubers but specimens of a rare subterranean fungus locally known as Nilamanga, or Earth Mango. This rediscovery, reported in early May 2026, has reignited scientific curiosity about one of Kerala's hidden natural treasures.

The fungus, thriving in termite-rich, moist soils typical of Kerala's post-monsoon landscape, had not surfaced in documented records for years. Its reappearance highlights the unpredictable nature of underground ecosystems, where environmental cues like high humidity and termite activity trigger growth. Local residents preserved the finds, drawing researchers to the site and sparking a wave of biodiversity enthusiasm.

🌱 Morphology and Habitat: Understanding the Earth Mango's Underground World

Nilamanga, scientifically identified as Sclerotium stipitatum Berk. et Curr., presents a striking appearance. Externally black and rugged, it reveals a firm, white interior when cut open, attached to slender stalks buried deep in the soil. Unlike epigeal mushrooms that fruit above ground, this hypogeal fungus remains concealed, often emerging from termite mounds or old debris during Kerala's Mithunam and Karkkidakam months, corresponding to peak monsoon influences.

Its habitat is intimately tied to subterranean termite colonies, where white ants cultivate it as a food source. The sclerotia—hardened fungal masses—serve as survival structures, enduring dry spells until conditions favor expansion. In Kerala, such environments abound in the Western Ghats foothills, but modern agriculture with chemical inputs disrupts this balance, making sightings increasingly scarce.

Deep Roots in Kerala's Traditional Ethno-Medicinal Practices

For generations, Kerala's tribal and rural communities have revered Nilamanga for its therapeutic potential. Healers crush the fungus, warm it in coconut oil, and apply drops for ear pain relief. Decoctions treat coughs, colds, stomach discomfort, jaundice, vomiting, and body aches. Folklore extends its use to arthritis, gastric issues, and even cancer, positioning it as a versatile remedy in Ayurvedic and folk traditions.

This traditional ecological knowledge, passed orally, underscores the fungus's role in biodiversity conservation. Locals recognize black powdery filaments surfacing from soil as indicators of underground Nilamanga clusters, guiding sustainable harvesting without overexploitation. Such practices bridge cultural heritage and modern science, prompting researchers to validate claims through rigorous testing.

Taxonomic Journey: From Folk Name to Scientific Confirmation

The taxonomic history of Nilamanga traces back to 1862 when British botanist Miles Joseph Berkeley described Sclerotium stipitatum from Travancore specimens. Early confusions arose, but a pivotal 2015 study from the University of Calicut's Department of Botany clarified its identity through morphological and molecular analyses. Researchers K.P. Deepna Latha, Sheeba Veluthoor, and Patinjareveettil Manimohan compared fresh Kerala samples to herbarium specimens at Kew, confirming the match while noting its termite symbiosis.

Further, the Swaminathan Foundation documented it in their publication Aushadhakkoonukal (Medicinal Fungi), cementing its ethnomedicinal status. These efforts highlight how Indian academia integrates field collections with phylogenetic tools like DNA sequencing to resolve long-standing ambiguities in fungal classification.

Explore the detailed taxonomic analysis in this 2015 Phytotaxa publication.

Academic Pioneers: St. Thomas College's Groundbreaking Contributions

At St. Thomas College (Autonomous) in Thrissur, Kerala, the Botany Department has led Nilamanga research. Dr. Anto P.V. spearheaded a UGC-funded minor project (2015) titled "Habitat, Taxonomic and Biochemical Studies on Sclerotium stipitatum (Nilamanga): A Rare Termite Fungus." The study collected samples from Thrissur and Palakkad, cultured isolates, and analyzed extracts via GC-MS, identifying phytosterols and bioactive compounds akin to anti-HIV and antitumor agents.

In-vitro cytotoxicity tests revealed no harm to human or animal cells, validating safe ethnomedicinal use. Building on this, PhD scholar Alina K. Sebastian (guided by Dr. Anto P.V.) completed her thesis in 2022 on molecular characterization and anticancer activity, employing advanced genomics to profile its proteome. These works exemplify how autonomous colleges in Kerala drive mycology forward, fostering student-led innovation amid resource constraints.

Photo by Ling App on Unsplash

Pharmacological Promise: Validating Medicinal Claims Through Science

Recent pharmacological probes affirm Nilamanga's potential. A 2021 study in the Journal of Pharmacy Research International tested ethanol extracts in animal models, demonstrating significant anti-inflammatory effects in acute (carrageenan-induced paw edema) and chronic (cotton pellet granuloma) inflammation, rivaling standard drugs like diclofenac. GC-MS identified compounds like 9-Octadecenoic acid and stigmasterol, known for immunomodulatory properties.

Anticancer assays from St. Thomas College showed selective cytotoxicity against tumor lines without affecting normal cells, hinting at novel chemotherapeutic leads. Step-by-step extraction—petroleum ether to aqueous—revealed solvent-specific bioactives, guiding future drug development. While human trials are pending, these findings bridge Ayurvedic lore and evidence-based pharmacology.

Read the full anti-inflammatory research here.

Subterranean Biodiversity: Kerala's Hidden Fungal Underworld

Kerala's tropical climate nurtures immense subterranean biodiversity, yet fungi remain understudied. Sacred groves like Kollakal Thapovanam boast high soil fungal diversity per 2024 metagenomic surveys from Kerala University researchers, revealing endemics via ITS sequencing. Termite-fungus symbioses, exemplified by Nilamanga, form underground networks recycling nutrients, akin to mycorrhizal webs.

Western Ghats mangroves and forests host diverse hypogeal species, but metagenomics uncovers 1000+ operational taxonomic units per site. Nilamanga's rediscovery spotlights this realm, where termites cultivate fungi like Termitomyces, enhancing soil health. Universities like Calicut and Kerala Agricultural drive inventories, using eDNA to map elusive taxa.

Threats to Underground Ecosystems: Agriculture and Climate Pressures

Intensifying farming erodes Nilamanga habitats. Chemical pesticides kill symbiotic termites, while monocultures reduce soil moisture. A 2020 study on subterranean termites across South India documented declining diversity in Kerala plantations, linking it to eucalypt invasions disrupting native mounds.

Climate shifts exacerbate risks: erratic monsoons alter sclerotia dormancy, per IIT Bombay models on humid heatwaves. Conservation demands agro-ecological shifts, like organic termite-friendly practices, to preserve these keystone species.

Conservation Strategies: From Academia to Community Action

Indian researchers advocate in-situ preservation. St. Thomas College's cultivation trials aim for ex-situ banks, while University of Calicut proposes sacred grove extensions as fungal refugia. Community protocols—harvesting only surfaced filaments—sustain yields.

• Metagenomic monitoring for early detection
• Termite mound protection in farmlands
• Bio-prospecting with benefit-sharing
• Public awareness via college outreach

Collaborations like Kerala Forest Research Institute's fungal atlases integrate data for policy.

Future Research Horizons: Unlocking Fungal Pharma Frontiers

The 2026 rediscovery opens doors for multi-omics studies: genomics for biosynthetic genes, metabolomics for novel antibiotics. Kerala universities eye CRISPR-edited strains for scalable production. Globally, subterranean fungi yield 30% of antibiotics; Nilamanga could join ranks.

Interdisciplinary teams—botanists, pharmacologists, ecologists—promise breakthroughs. For aspiring researchers, projects like St. Thomas' exemplify accessible entry via UGC grants, fostering India's mycological talent.

Stay updated via the Times of India coverage on this unfolding story.

Photo by Yuval Zukerman on Unsplash

Implications for India's Biodiversity Research Landscape

This event underscores Kerala's role as a fungal hotspot, urging national inventories. With 2.2-3.8 million fungal species estimated globally, India's 1.5 million undescribed demand academic investment. Colleges like St. Thomas bridge gaps, training PhDs for sustainable discovery.

As subterranean realms reveal climate sentinels, research pivots to resilience metrics, positioning Indian higher education at the vanguard of global mycology.