Sterculia setigera Delile is a valuable, drought-tolerant, deciduous tree native to the Sahel-Sudan and Guinea savanna zones of tropical Africa, commonly known for its medicinal gum and edible seeds. It is a member of the Malvaceae family and can grow up to 15–30 meters tall.
Karaya gum tree (Sterculia setigera, family Malvaceae) is a deciduous tree or large shrub with a large, open, spreading crown, generally up to 16 metres tall. Its grey bark peels in patches, and its leaves are broad and lobed. The wood is white and very soft, and fibre from the inner bark is used for rope. Male and female flowers grow on separate trees. The fruits split open to release deep purple seeds 10 to 14 mm long, and the inside of the fruit is lined with irritating hairs. Cuts in the trunk and branches yield karaya gum, which hardens into irregular "tears".
It ranges from Senegal to Eritrea and south to Angola and Tanzania, in savanna, wooded grassland, bushland and dry riverine forest. It often grows on stony hills, rocky slopes, black cotton soil and laterite. The seed has a hard coat. Once the coat is nicked and the aril removed, about 95% germinates within two weeks.
Source: Useful Tropical Plants database (Fern, K.).
Gum, bark, and leaves are used to treat malaria, jaundice, diarrhea, fever, respiratory issues, wounds, and skin infections, with antibacterial, anti-inflammatory, antioxidant, and anti-plasmodial properties.
The seeds are roasted and eaten for their high protein and oil content, and the gum is used as a thickener or emulsifier in cooking.
The gum is harvested for trade, the bark is used for ropes and mats, the wood as fodder, and the tree holds socio-economic and cultural significance in sub-Saharan Africa.
The tree is mainly propagated by seeds, often soaked to improve germination, and can be grown using vegetative or tissue culture techniques like micrografting.