Calophyllum inophyllum

Calophyllum inophyllum, known locally as Domba in Sinhala, is one of the most recognisable coastal and lowland trees of Sri Lanka. A member of the family Calophyllaceae, it grows naturally across the Indo-Pacific region — from East Africa and the Indian subcontinent through Southeast Asia to the Pacific islands — but holds a particularly prominent place in Sri Lankan Ayurvedic tradition, coastal ecology, and everyday rural life.

What does Calophyllum inophyllum look like?

The Domba tree is a medium to large evergreen, typically reaching 8–20 metres in height, with a broad, spreading canopy that makes it a favoured shade tree along Sri Lanka's coastal roads and temple grounds. Its bark is rough and dark, exuding a sticky yellow latex when cut. The leaves are oval, leathery, and glossy green, with distinctive parallel veins running perpendicular to the midrib — a useful identification feature. Fragrant white flowers, each with four petals and a cluster of yellow stamens, appear in clusters along the branches and attract pollinators including bees and birds.

The fruit is round, roughly the size of a large marble, and turns from green to yellow or dark purple when ripe. Inside the fruit, a large seed contains oil-rich kernels that have been pressed and used for centuries across South and Southeast Asia.

Where does Calophyllum inophyllum grow in Sri Lanka?

In Sri Lanka, Domba trees are most abundant in the coastal lowlands of the wet and intermediate zones — from the western coast around Negombo and Colombo south through the Galle district. The species thrives in sandy coastal soils, riverbanks, and humid lowland forests up to around 200 metres above sea level. It is commonly planted along beach margins and tank bunds, where its deep root system helps stabilise soils. Mature trees are frequently seen near ancient temples and historic settlements, where they have been deliberately cultivated for generations.

Within Sri Lanka's mangrove and coastal wetland ecosystems — such as those found at Madu Ganga — Calophyllum inophyllum grows along the transition zone between freshwater and saltwater influence, often forming part of a mixed coastal forest alongside other indigenous species.

What are the Ayurvedic and medicinal uses of Domba?

Calophyllum inophyllum has an extensive place in the Ayurvedic pharmacopoeia of Sri Lanka. The tree contributes several usable parts — bark, leaves, flowers, seed oil, and latex — each with documented traditional applications.

• Domba oil (Tamanu oil): Cold-pressed from the dried seeds, this dense green oil is perhaps the most widely recognised product of the tree. It has been used topically in Ayurvedic and traditional Pacific medicine for wound healing, skin conditions such as eczema and psoriasis, and joint pain relief. Modern pharmacological research has identified anti-inflammatory, antibacterial, and analgesic compounds in the oil, including calophyllolide and inophyllum B.
• Bark and latex: The bark decoction has traditionally been used as an astringent and for treating conditions affecting the skin and mucous membranes. The latex has been applied externally for rheumatic pain.
• Leaves: Leaf extracts have been used in traditional formulations to address eye complaints and headaches, though clinical evidence for these uses remains limited.
• Flowers: Occasionally used in fragrant preparations; the floral scent is also valued for its calming association in ritual contexts.

As a documented component of Sri Lanka's Ayurvedic materia medica, Domba is referenced in classical texts and is cultivated in botanical gardens associated with traditional medicine. Its profile sits alongside other medicinally significant trees such as Pongamia pinnata, another oil-bearing leguminous tree with parallel therapeutic uses in the island's indigenous medicine tradition.

What is the ecological and cultural significance of the Domba tree?

Beyond medicine, Calophyllum inophyllum carries considerable cultural weight in Sri Lanka. The tree is associated with Buddhist temple grounds — its dense shade and longevity make it well-suited to the contemplative environment of a viharaya. Older specimens can live for several centuries, and some trees found near historic sites are believed to pre-date the structures they shade.

Ecologically, the tree provides habitat and food for a range of wildlife. Its flowers are rich in nectar, supporting local bee populations, while the fleshy fruit is consumed by fruit bats and birds, which disperse the seeds. The dense canopy reduces coastal erosion and moderates microclimate temperatures in lowland areas.

Domba timber is also valued for its durability. The wood is hard and resistant to moisture, historically used for boat building, furniture, and structural elements in traditional Sri Lankan construction. Sri Lankan fishermen have long favoured it for outrigger components and boat planking — a practical recognition of the tree's resilience in humid coastal environments.

How is Domba oil produced and used today?

Traditional production involves collecting ripe fruits, drying them over several weeks until the kernels can be extracted, and then cold-pressing or solvent-extracting the oil from the dried kernel. The resulting raw oil is thick, dark green, and strongly scented. Refined versions are lighter in colour and more neutral in smell, making them suitable for cosmetic formulations.

Today, Domba oil is exported from Sri Lanka as part of the growing global demand for natural plant-based skincare ingredients. It appears in formulations for scar treatment, sun-damaged skin, and anti-ageing products. Research interest has also grown around its potential as a biofuel feedstock, given the high oil content of the seed and the tree's ability to grow in degraded coastal soils without competing with food crops.

Is Calophyllum inophyllum related to other Sri Lankan medicinal plants?

The Domba tree is one of several hundred plant species documented in Sri Lanka's Ayurvedic tradition. It shares some overlapping applications with other oil-bearing or resin-producing trees in the island's pharmacopoeia. Practitioners of traditional medicine often combine plant materials — seeds, barks, and leaves from multiple species — into compound formulations. Trees such as Acacia chundra similarly contribute bark extracts used for their astringent properties in traditional preparations.

Sri Lanka's tropical climate and biodiversity create ideal conditions for a rich native pharmacopoeia, and the country's Ayurvedic research institutions continue to study and document plants like Calophyllum inophyllum as part of efforts to preserve and validate traditional knowledge.

Conservation status and sustainability

Calophyllum inophyllum is not currently considered threatened globally, but coastal development pressure in Sri Lanka has reduced natural populations along some shorelines. The species is listed in conservation programmes within coastal buffer zones, and replanting initiatives have been undertaken following tsunami and storm damage to coastal forest cover. Its value as a soil stabiliser, combined with commercial interest in its oil, makes it an attractive candidate for sustainable agroforestry systems in Sri Lanka's coastal districts.