African Pearwood, False Shea Butternut
Baillonella toxisperma

Family: Sapotaceae

What it is like

African Pearwood (Baillonella toxisperma), otherwise known as False Shea Butternut, is a large, tropical tree that can reach up to 60 m high with a trunk diameter of up to 300 to 500 cm. It has a straight and cylindrical bole, alternately arranged leaves, and round fruits. In traditional medicine, the seed kernel of this plant is used for its fatty oil content to treat rheumatism. In particular, the oil is applied externally to the pained area caused by such ailment. Decoctions of the bark are used against kidney conditions, tooth pain, rickets, vaginal infections, and problems in respiratory and digestive tracts. The fruit pulp, though it contains latex, is eaten fresh. The fatty oil obtained from the seeds is also used in cooking. It is also used as pomade to the hair and in soap making. The wood is heavy, hard, elastic, and very durable. Not to be confused with Dacryodes edulis, the African pear.

Baillonella toxisperma is a deciduous Tree growing to 50 m (164ft) by 40 m (131ft) at a fast rate. See above for USDA hardiness. It is hardy to UK zone 10. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils and prefers well-drained soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils and can grow in very acid and very alkaline soils. It can grow in semi-shade (light woodland) or no shade. It prefers moist soil.

Height (m): 50

Where it is found

Usually scattered in primary rainforest on all soil types except marshy soil.

Western tropical Africa - southern Nigeria to Gabon, Congo and south-western DR Congo.

Conservation Status: Vulnerable

Countries/locations it is found in

Found In: Africa, Cabinda, Cameroon, Central Africa, Central African Republic, CAR, Congo DR, Congo R, Gabon, Ghana, Nigeria, West Africa.

How it is used

Food

Rating: 3

Edible portion: Nut, Seeds - oil, Fruit. The fruit pulp is eaten fresh although it contains latex. The seed kernel contains a fatty oil that is used in cooking. The residue after extracting the oil is toxic.

Oil: Oil

Seed: includes nuts, cereals, peas and beans.

Medicine

Rating: 3

The seed kernel contains a fatty oil that is used in traditional medicine. It is applied externally to treat rheumatic pains. Bark decoctions are used to treat kidney problems, toothache, rickets, vaginal infections and affections of the respiratory and digestive tracts.

Antirheumatic: Treats rheumatism.

Kidney: Used in the treatment of kidney diseases

Odontalgic: Treats toothache (temporary measure only) and other problems of the teeth and gums.

Pectoral: Relieves respiratory diseases, a remedy for chest diseases.

Other

Rating: 4

Other uses rating: High (4/5). Other Uses The seed kernel contains a fatty oil that is used as a pomade to the hair and also in soap manufacture. The allelopathic compound 3-hydroxyuridine has been isolated from the leaves, stems and roots of the tree. It inhibited the growth of seedlings of some test plants. The heartwood has a uniform reddish brown colour, more or less dark and finely veined; it is clearly demarcated from the 4 - 6cm wide band of sapwood. The texture is fine; the grain straight or interlocked. The wood is heavy, hard, elastic, very durable, with a resistance to fungi, Lyctus beetles, termites and marine borers. It is difficult to work due to the presence of silica (0.2 - 0.3%) - power tools that are stellite-tipped and tungsten carbide are recommended; it glues correct, though care needs to be taken because of the density of the wood; it takes nails and screws well, but pre-boring is required; it finishes well; and has good steam-bending properties. Painting and varnishing with the principal industrial products do not cause problems. It is used for many purposes including high class cabinetwork, joinery and carpentry in both interior and exterior applications, marine construction, flooring, turnery, railway sleepers, decorative uses and veneer.

Hair: Plants used as hair shampoos, tonics, to treat balding etc.

Oil: Vegetable oils have many uses, as lubricants, lighting, soap and paint making, waterproofing etc. This does not include the edible oils unless they are also mentioned as having other uses.

Soap making: Plants used as an ingredient in making soaps. Does not include the essential oils, dyes and oils that are also used in making soap.

Wood: A list of the trees and shrubs that are noted for having useful wood.

Food Forest: Plants for Edible Forest Gardens and Food Forests.

How it is grown

The tree occurs in primary rain forest in humid and warm climates, with a mean annual temperature of 23 - 26°c and a mean annual rainfall of 1,500 - 3,000 mm. Seeds germinate in abundance under or close to mother trees. However, young plants of 1 metre tall are rare as a result of predation by animals, mainly elephants, and the survival rate of seedlings after 18 months is practically nil under the mother tree and very low (less than 2%) elsewhere. In forest undergrowth seedlings grow 4 - 5 cm/year. They respond rapidly to the opening of the forest cover and direct sunlight, and under these circumstances may grow up to 40 cm/year. When the tree bole has attained 1m in diameter and the crowns have reached or passed the forest canopy, diameter growth is up to 9.5 mm/year. It has been estimated from growth rings and C14 dating that a tree with a bole diameter of 1 metre was 260 years old and one with a diameter of 2.8 metres 600 - 700 years. The tree starts flowering at an age of 50 - 70 years, when it has reached the light in the upper storey of the forest, but regular fructification starts still later, when the bole has reached 70 cm in diameter. Fruits are produced annually, but mass production occurs once in 3 years. About 6,000 seeds per tree are produced within a cycle of 3 years; a single tree produced 2,460 kg of fruits, including 327 kg of seed kernels. The fruiting season lasts up to 4 weeks for an individual tree, but may last 3 months for a whole wild population. At present, the only management measure for natural forest is the maintenance of a minimum diameter limit for exploitation, i.e. 70 cm in Gabon, 80 cm in Congo and 100 cm in Cameroon. In Cameroon commercial exploitation of the tree implies the cutting of 90% of trees above 100 cm in diameter, leaving only poorly shaped trees. It has been estimated that after 300 years 84% of the harvested volume is re-established and after 500 years 92%. Sustainable production in natural forest is therefore not possible. Cutting cycles of 30 years, as often practised, threaten the populations seriously. During the fruiting season, local people often move to localities where clusters of trees are found and stay there in temporary camps for 2 - 8 weeks. The collected fruits are depulped and the seed kernels dried. After heating, the oil is gathered by pressing with a traditional wooden press. The oil is used domestically or sold. It can be stored for 1 - 2 years. In 1992, which was a very good year for fruit production, the yield of oil was estimated at 135 - 165 litres per adult tree.

Propagating it: Seed. Shade is required for germination, which usually takes 1 - 4 weeks. The germination capacity of fresh seeds is high (> 85%), but drops rapidly to 5% after 6 weeks of storage due to rapid degradation of the fatty acids. However, fresh seeds stored at 4?C and humid conditions still showed a germination rate of about 50% after 11 months. In the nursery the lower half of the seed is buried, with the scar pointing downwards. The mortality of seedlings in the nursery is very low. Partial shading is favourable for seedling development. Under optimal nursery conditions seedlings may reach 35 cm in height after 6 weeks, 45 cm after 3 months and 1.5 metres after 18 months. The seedling develops a taproot and so it is recommended to sow into polythene pots. Seedlings are planted out into the field, when about 4 - 5 months old, at the start of the rainy season under the light shade of about 10 retained adult trees per ha. The shade should be removed gradually when a reduction in diameter growth is observed. Seeds germinate in abundance under or close to mother trees - whilst it is not necessary for the seeds to pass through the intestines for germination, it does accelerate germination slightly.

Best place to grow:

Habit: Tree

Hardiness: 10-12

Growth: Fast

Soil: Light (sandy), medium, heavy (clay)

Shade: Semi-shade, no shade

Moisture: Moist

Things to keep in mind

The residues of oil extraction are sometimes used as fish poison. Sawdust from the wood can irritate mucous membrances.

Its other names

Local names

African Pearwood (Baillonella toxisperma), otherwise known as False Shea Butternut. Not to be confused with Dacryodes edulis, the African pear. Other Names: Adjap, Adza, Djave Nut Gio, Mabi, Moabi, Njabi, Njap, Oko uku.

Synonyms

Baillonella djave (Engl.) Pierre ex Dubard. Baillonella pierriana (Engl.) A.Chev. Mimusops djave Eng