Detarium is a small genus of large tropical trees in the family Fabaceae (order Fabales), native to sub-Saharan Africa. The genus contains three closely related species — Detarium microcarpum, Detarium senegalense, and Detarium macrocarpum — each adapted to a distinct vegetation zone: D. microcarpum grows in dry savannahs, D. senegalense in riparian and dry-forest zones, and D. macrocarpum in humid closed-canopy forest.
Trees in the genus are deciduous, typically reaching 15–36 metres in height with a relatively short bole and a broad, dense crown. The wood is grey, hard, and fine-grained; it is insect-resistant and has been used as a mahogany substitute in carpentry and joinery. Like many legumes, Detarium species form symbiotic associations with nitrogen-fixing root bacteria.
The genus is notable for its edible and medicinally important fruit. D. senegalense — known in parts of West Africa as the "tallow tree" or ditakh — produces a drupe with a green, sweet-flavoured mesocarp that is eaten raw or dried and sold in local markets; the sweet pulp has historically served as a sugar substitute. However, a distinctive and unusual feature of the genus is that fruit toxicity varies by individual tree: some trees of D. senegalense produce poisonous fruit while others of the same species produce non-toxic fruit, and there is no reliable way to distinguish them once fruit is separated from the tree. The bark is also reported to be poisonous. Various parts of the plant — fruit, seeds, bark, leaves, and wood — are used in traditional medicine across West Africa. Trees also yield a fragrant resin.
Distribution
Detarium is native to sub-Saharan Africa, ranging from Senegal in the west to Sudan and the Democratic Republic of the Congo in the east. Individual species occupy distinct niches: D. microcarpum in dry savannah, D. senegalense in riparian and moister savannah forest up to 650 m elevation, and D. macrocarpum in humid closed-canopy forest.
Ecology
Detarium senegalense grows in closed and fringing forest within moister savannah regions as well as open savannah and riparian corridors, at elevations to 650 m, in areas receiving approximately 1,500–1,600 mm of annual rainfall. All Detarium species form symbiotic root nodules with nitrogen-fixing soil bacteria, enriching soil nitrogen for surrounding vegetation.
Cultural Uses
Across West Africa, Detarium trees are important multi-use resources. The sweet fruit pulp of D. senegalense (ditakh) is eaten fresh or dried, sold in local markets, and used as a substitute for sugar. The hard, insect-resistant wood is used for carpentry, joinery, and firewood — it lights readily even when wet and burns slowly with a pleasant aroma. The tree also produces a fragrant resin. Various plant parts (fruit, seeds, bark, leaves, wood) figure in traditional medicine. D. senegalense is semi-cultivated in Senegal, where it occupies a role between wild-gathered forest product and managed crop.
