Isoberlinia doka (doka)

Native to west and central Africa, Isoberlinia doka is a major constituent of the woodland belt which stretches from Guinea in the west to Sudan and Uganda in the east. It also occurs extensively to the south of these woodlands, but in a more scattered manner, and is unknown south of the equator. I. doka occurs in Benin, Burkina Faso, Cameroon, Central African Republic, Chad, Côte D’Ivoire, Democratic Republic of the Congo (formerly Zaire), Ghana, Guinea, Mali, Niger, Nigeria, Sudan, Togo, and Uganda.

Isoberlinia doka is a tree measuring 10-20 m tall with a trunk of about 40-50 cm diameter, branching from about 5 m upwards. The leaflets are arranged in three or four pairs. The flowers are small and white, forming large open inflorescences that are held conspicuously above the leafy crown. The pods are oblong, flat and quite large, about 30 cm long and 10 cm wide. When they are mature, the two halves twist apart with such force that they can expel the seeds about 50 cm from the tree.

Herbarium specimen of Isoberlinia doka collected in Nigeria by Dalziel, J.M. in 1911 (Image: RBG Kew)

Widespread in west and central Africa, Isoberlinia doka populations appear to be stable at present, and not unduly affected by harvesting for timber and other uses. However, the tree is known to be fire-sensitive, so any drying of the climate in the future may potentially pose a threat to some stands. There are no known conservation measures currently in operation specifically for I. doka, but it does grow in many protected areas. Samples of seed have been collected and are held in Kew’s Millennium Seed Bank as an ex situ conservation measure. It is recommended that further monitoring should be carried out to ensure this species is not over-exploited in the future.

Conservation assessments carried out by Kew

Isoberlinia doka is being monitored as part of the Sampled Red List Index Project, which aims to produce conservation assessments for a representative sample of the world’s plant species. This information will then be used to monitor trends in extinction risk and help focus conservation efforts where they are needed most.

Widely exploited for its timber in West Central Africa, Isoberlinia doka is used in carpentry and for making furniture, although the wood is somewhat difficult to work with hand-tools. It is also used as fuelwood. It is used for treating muscular-skeletal system disorders in traditional West African medicine. An infusion of the leaves is used for treating jaundice. Doka is also used to treat infectious diseases, and scientific investigations have confirmed its antibacterial activity. The tree is thought by some to have magical properties. It is potentially useful for land reclamation and reforestation schemes on account of its vigour, and ability to colonise clearings and abandoned land.

Kew's Millennium Seed Bank Partnership aims to save plant life world wide, focusing on plants under threat and those of most use in the future. Seeds are dried, packaged and stored at a sub-zero temperature in our seed bank vault.

Number of seed collections stored in the Millennium Seed Bank: One.

Dried and spirit-preserved specimens of Isoberlinia doka are held in the behind-the-scenes Herbarium at Kew, where they are available to researchers from around the world, by appointment. The details, including images, of some of these specimens can be seen on-line in the Herbarium Catalogue.

Search Kew's databases for more information on this species 

Kew’s Leguminosae science team

More about the legume family

Buy 'Legumes of the World' by G. Lewis, B. Schrire, B. Mackinder & M. Lock (eds.)

Buy 'The Useful Plants of West Tropical Africa, Volume 3' by H.M. Burkill

SEPASAL (Survey of Economic Plants for Arid and Semi-Arid Lands)