Common Name:

General Information

Allanblackia stuhlmannii is an evergreen, medium-sized to fairly large tree that can grow up to 35, occasionally to 45 metres tall[]. The straight bole can be clear of branches for up to 9 metres, up to 65cm in diameter, and is occasionally buttressed[, ].
The tree is of local importance, particularly for its oil-bearing seed and timber, and has attracted attention from the International food industry[]. Although not usually cultivated, the tree is usually retained in farmland when the forest is cleared[]. The seeds are sold in local markets and have been exported to Europe[, ].
Found only in Tanzania, the tree is listed as vulnerable in the IUCN Red List because of its small and severely fragmented areas of distribution and declining habitat[]. Natural regeneration is currently not adequate to maintain existing stands[].

Known Hazards

None known

Botanical References

Range

Eastern Africa - Tanzania.

Habitat

Seaward slopes and valley bottoms of evergreen submontane and montane forest at elevations of 800 - 1,200, occasionally to 1,600 metres[].

Properties

Conservation Status	Vulnerable
Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Evergreen Tree
Height	35.00 m
Pollinators	Insects, Birds, Bats
Self-fertile	No
Cultivation Status	Semi-cultivated, Wild

Cultivation Details

A tree of the tropics, average annual rainfall in its habitat is 1,100 - 2,400mm with more than 180 rainy days a year[]. The mean annual temperature is 18°c, maximum temperatures range from 25°c to 35°c whilst minima are occasionally as low as 3°c[].
Grows best in a sunny position[].Trees grow naturally on mostly acidic clay soils derived from granite, gneiss or siliceous rock[]. Prefers a well-drained soil[].
Under natural conditions, trees first flower when about 12 years old. Flowering is during the short rainy season in November - February and the fruits take more than 1 year to develop and mature[]. A mature tree may yield up to 150 fruits or up to 50 kg fat per year[].
The trees are fire-tolerant[].
The fat from the seeds of Allanblackia stuhlmannii is very similar in composition to that of Allanblackia parviflora and Allanblackia floribunda[].
A dioecious species, both male and female forms must be grown if seed is required[].
Female trees are often retained when clearing land for agriculture, but planting is still rare. It is estimated that 1 male tree per 10 female trees is needed to ensure adequate pollination[].
ICRAF, Kenya, is studying possibilities to domesticate this species and develop appropriate management techniques. A complete seed marketing chain is also being developed[]. Selection of high-yielding trees for vegetative reproduction has started in Tanzania[].

Edible Uses

An edible non-drying fat, called Mkani fat, is obtained from the seed[]. It is locally important[], where it is used in cooking and has been used as a substitute for butter and cocoa butter[].
Air-dried seeds contain about 50% fat[]. The fatty acid composition of the fat is remarkable as it consists mainly of stearic acid (45 - 58%) and oleic acid (40 - 51%)[]. Only traces of other fatty acids are present. Its composition and resulting high melting point (35°c) makes the fat a valuable raw material that can be used without transformation to improve the consistency of margarines, cocoa butter substitutes and similar products[].
Seeds are extracted from the fruits by crushing them between the hands and rubbing them clean. Traditionally, the seeds are dried and crushed; the resulting mass is mixed with water and boiled until the fat separates and floats to the surface from where it is scooped off[].

The fruit’s slimy jelly-like pulp can be used in jam making[].

Medicinal

In traditional medicine, the leaves are chewed to treat cough, while the leaves, bark and roots are used to treat impotence[, ].

A seed extract is rubbed in to treat rheumatism[].

The fat is applied as a liniment on aching joints, wounds and rashes and small quantities are taken orally to treat rheumatism[, ]. The fat, mixed with the pounded seeds of Psorospermum febrifugum, is rubbed on deep cracks in the soles of the feet[].

Guttiferone F, a prenylated benzophenone, has been isolated from the wood of the roots[]. The compound is related to a group of compounds that has been investigated for its anti-HIV properties[].

Other Uses

The bark is a source of a red dye[]. The bark yields a yellow dye[, ].

The fat from the seed is used to make candles[].

The heartwood is dark brown to purplish, usually present only as a small core - for example there would be around 10cm of heartwood in a bole of 65cm; the sapwood is pale grey-brown. Texture is medium; the grain straight. The wood air dries slowly, with a moderate tendency to cup, but with little or no splitting. It is difficult to saw when green, but once dry it saws easily and machines well. It holds nails well. The sapwood is not durable, but is permeable to preservatives; the heartwood is very resistant[]. The wood is used for construction, cheap joinery, boxes, crates, beehives and water containers[, ].
The wood is used for fuel[].

Propagation

Seed. Well-matured fruits are kept for about 2 weeks to allow the pulp to become soft and to make extraction of the seed easy. Fruits may be kept for up to 3 months if covered with banana leaves. Clean seeds are placed in a nursery where they take about 3 months to start to germinate, but germination may take more than 7 months to start and another 18 months to complete[]. After germination the seedlings are transferred to polythene tubes filled with soil. Mycorrhizae are necessary for successful growth of the seedlings and it is therefore important to add soil from around the base of mother trees to the substrate[].
Cuttings are placed a few cm deep in soil at a 45° angle in polythene tubes with at least 1 node above the substrate. Cuttings strike root in 8 - 12 weeks, after which sprouted and rooted cuttings are transferred to polybags[].
Methods of layering and budding are being developed. Initial tests with wildlings have shown good survival rates both with farmers and in experiments[].

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