Kathurumurunga — known botanically as Sesbania grandiflora and colloquially as the hummingbird tree — is one of Sri Lanka's most useful multi-purpose trees. A member of the legume family Fabaceae, it grows rapidly across the island's lowland and mid-elevation zones, thriving in warm, humid conditions and absent only from cooler highland regions. Its fast growth is both a strength and a limitation: a mature tree may complete its life cycle within a few years, making it a short-lived but highly productive addition to home gardens and small farms.
What does the Kathurumurunga tree look like?
A typical Kathurumurunga tree reaches around 8 to 10 metres in height. Its leaves closely resemble those of the tamarind (Siyambala), with each compound leaf measuring up to 30 cm in length and carrying 5 to 15 pairs of small elliptical leaflets roughly 3 cm long. The bark is light grey, and the wood beneath is notably soft and pale. The fruit is a slender pod that can grow up to 60 cm in length, containing between 15 and 50 seeds.
There are four recognised flowering varieties: white, red, blue, and yellow. The white and red flowering trees are by far the most common across Sri Lanka. Blue and yellow flowering specimens exist but are relatively rare and less frequently cultivated.
When does Kathurumurunga flower?
Flowering typically occurs in September and October, when the tree produces large, showy blossoms measuring 7 to 9 cm in length. The white-flowered variety produces cream to ivory blooms, while the red variety carries rose-pink to deep red flowers. Both are the varieties most commonly used for food and medicine; the blue and yellow varieties are generally not harvested for culinary purposes.
How is Kathurumurunga used in Sri Lankan cooking?
The leaves and flowers of the white and red Kathurumurunga varieties are a staple ingredient in Sri Lankan home cooking. Kathurumurunga mallum — finely chopped leaves tossed with grated coconut, lime, and spices — is one of the island's most recognisable side dishes. A fresh sambol made from the leaves is equally popular and pairs well with rice and curry.
The flowers are also eaten, most often lightly blanched or stir-fried. Both leaves and flowers contribute a mildly bitter flavour that balances well against the richer, creamier elements of a Sri Lankan meal. Compared to introduced vegetables, Kathurumurunga is valued precisely because it grows quickly, requires little maintenance, and offers nutritional density. For a related native ingredient with a similarly long culinary and medicinal history, see Pongamia pinnata.
What are the medicinal and nutritional properties of Kathurumurunga leaves?
In traditional Sri Lankan and Ayurvedic practice, all parts of the Kathurumurunga tree — leaves, flowers, bark, and root — are attributed with therapeutic qualities. The leaves are particularly well documented in local medical texts.
- The leaves are considered a natural coolant and are traditionally used to help manage fever, sinus complaints, and respiratory discomfort.
- They are believed to have antimicrobial properties, with leaf juice used in folk remedies for nausea, gout, skin itchiness, and certain skin conditions.
- Crushed leaves are applied externally to relieve sprains and bruises.
- Kathurumurunga leaves are rich in Vitamin E and are also said to assist with digestive complaints including constipation.
- Postpartum, boiled Kathurumurunga leaves are traditionally given to new mothers to support lactation.
- The white-flowered variety is specifically cited in Ayurvedic literature as suitable for medicinal use.
Beyond human use, the leaves serve as fodder for livestock and as green manure, making the tree genuinely multi-functional on small farms and homesteads.
What are the health benefits of Kathurumurunga flowers?
The flowers are nutritionally distinct from the leaves and carry their own set of traditionally ascribed benefits. They are a good source of calcium, iron, and Vitamins A and B. In Sri Lankan traditional medicine, the flowers have been used to help relieve headaches and nasal congestion.
The flowers also contain tannins and other bioactive compounds, which have attracted interest in natural skincare. Extracts are used in some anti-ageing formulations, where they are thought to support collagen production and assist in reducing the appearance of wrinkles, though clinical evidence for these applications continues to develop.
Where does Kathurumurunga grow in Sri Lanka?
Kathurumurunga is distributed widely across Sri Lanka's wet, intermediate, and dry zones. It is commonly found in home gardens, along roadsides, and at forest margins in low-country areas. It does not thrive at high elevations or in the cool temperatures of the central highlands. Because the tree grows quickly and fixes atmospheric nitrogen into the soil through its root nodules — a characteristic shared with other members of the Fabaceae family — it is also planted as a shade tree and soil improver in agricultural settings.
How is Kathurumurunga bark used?
The bark of Kathurumurunga is light grey in colour and relatively soft. While it is less commonly discussed in culinary contexts, the bark is noted in traditional practice for its astringent properties. It has been used in certain Ayurvedic preparations, though bark-based remedies are generally considered supplementary to leaf and flower treatments in everyday use.
Can you grow a Kathurumurunga tree at home?
Kathurumurunga is one of the easier trees to cultivate in a Sri Lankan garden or tropical home setting. It grows well from cuttings and seeds, tolerates a range of soil types, and requires relatively little attention once established. Given its rapid growth rate, a young plant can reach productive size within its first year. However, it is worth noting that the tree's lifespan is relatively short — typically a few years — so succession planting helps maintain a steady supply for cooking and home remedies. The tree prefers full sun and good drainage, and can be pruned regularly to keep it at a manageable height and to encourage fresh leaf growth.
What is the nutritional profile of Kathurumurunga leaves?
Kathurumurunga leaves are considered nutritionally dense relative to their size. They contain meaningful quantities of Vitamin E, which is less common in leafy vegetables, alongside protein, dietary fibre, and various minerals. The slightly bitter taste of the leaves is associated with the presence of beneficial plant compounds, and the leaves are generally prepared by blanching or stir-frying with coconut and spices to balance the flavour. Because the cooking process is brief, much of the nutritional content is retained in the finished dish.
