Agroforestree Database

Local names:
 English (native pear,bush butter tree,African plum,African pear,African palm), French (safoutier,prunier,atanga)

Dacryodes edulis is a medium-sized, evergreen tree attaining a height of 18-40 m in the forest but not exceeding 12 m in plantations. It is generally branched from low down, with a deep, dense crown. The bole is rather short, slightly fluted, 50-170 cm in diameter and more or less sinuous. The scented, pale grey, rough bark exudes a whitish resin. Buttresses are absent.

Leaves compound, imparipinnate, with 5-8 pairs of leaflets; glossy above, pubescent, the pubescence disappearing with age.

Flowers subtended, 3 lobed, conspicuous, caducous brow bracts, fragrant, about 5 mm across, trimerous except for the ovary, arranged in dense, ferruginous, stellate-tomentose inflorescence; sepals 3, brown; petals 3, cream-yellow; stamens 6, white; disc 6 lobed, surrounding the 2-celled, glabrous ovary; inflorescence axis 10-42 cm long or longer, deeply grooved.

Fruits ellipsoidal drupes rather variable in size, 4-12 x 3-6 cm, resembling olives; exocarp thin, pink, becoming dark blue to violet at maturity; pulp firm and thin.

On the basis of long-term and extensive field observations in Nigeria, 2 varieties of D. edulis were distinguished: D. e. var. edulis and D. e. var. parvicarpa. Fruit of D. e. var. edulis is large, elongated, cylindrical, usually more than 5 x 2.5 cm. The fruit pulp is thick, about 3.5-9 mm. The tree often has whorled branching, the branchlets stout and ascending. The fruit of D. e. var. parvicarpa is small, rounded or more or less conical, usually less than 5 x 2.5 cm. The fruit pulp is thin, about 2-3.5 mm. Often the tree has bifurcate branching, with slender, drooping branchlets. 

The generic name is derived from the Greek word 'dakruon' (a tear) in reference to the resin droplets on bark surface of its members. The specific name ‘edulis’ means edible.

Ecology

D. edulis is a shade-loving species of non-flooded forests in the humid tropical zone. Where there is a well-marked season, it is found only in gallery forest and on swampy ground. D. edulis can be cultivated widely, since it adapts well to differences in day length, temperature, rainfall, soils and altitude. It is planted in southern Nigeria, Cameroon and Democratic Republic of Congo for its nutritious fruit, which has a high oil content.

Native range
Angola, Benin, Cameroon, Central African Republic, Congo, Cote d'Ivoire, Democratic Republic of Congo, Equatorial Guinea, Gabon, Ghana, Liberia, Nigeria, Sierra Leone, Togo, Uganda

Tree management

The recommended spacing for planting D. edulis in orchards is 10 x 10 m. Care for the trees is minimal, often limited to slashing the weeds around each tree. Except when planting, fertilizing or manuring is not used; pruning and crop protection are not practised.

Germplasm collections have not been initiated for D. edulis, nor have any strategies been drawn up for genebanks or in situ reserves for the species. The seeds are recalcitrant, so ex situ collections will entail establishing orchard seed banks.

Storage behaviour is uncertain; whole seed moisture content is 42%; 25% germination following 14 days open storage at 15 deg. C, while no seeds germinate when stored at 25 deg. C or 5 deg. C.

D. edulis is a shade-loving species of non-flooded forests in the humid tropical zone. Where there is a well-marked season, it is found only in gallery forest and on swampy ground. D. edulis can be cultivated widely, since it adapts well to differences in day length, temperature, rainfall, soils and altitude. It is planted in southern Nigeria, Cameroon and Democratic Republic of Congo for its nutritious fruit, which has a high oil content.

No artificial selection has been attempted with D. edulis; thus there is a continuum of fruit sizes rather than clear-cut botanical races. It is usually propagated from seed sown either in the open ground or in long polythene bags. Germination is epigeal.

Vegetative propagation is difficult although some farmers keep or transplant wild trees, but air layering has proved successful (up to 80% take) and is now practised in a few areas, using selected mother trees. It takes 4-6 months before the layers can be separated and this should not be done when the mother tree is about to flush. Plantlets have been obtained by tissue culturing of cotyledons. In laying out an orchard, 5% of the trees should be male-flowering to ensure adequate cross-pollination.

  The principle value of the tree lies in its fruit. The leathery, shelled stone is surrounded by a pulpy, butryaceous pericarp about 5 mm thick, which is the portion eaten either raw or cooked in form of a sort of butter. It has a mild smell of turpentine and is oily. The fruits are boiled in saltwater, fried or roasted over charcoal. The fruit pulp yields about 48% edible oil, is rich in vitamins and contains a range of amino acids.

The kernel, which contains about 3.3% protein, is commonly fed to domestic livestock such as sheep and goats.

Apiculture: The native pear has attractive flowers because of the existence of nectar. During anthesis phases, the ovary produces a sweet substance which attracts bees and other insects. The species can be thus used as a melliferous tree.

Timber:  The wood is elastic, greyish-white to pinkish. The sapwood and heartwood are difficult to distinguish. The wood has general use for tool handles, particularly axe shafts, and occasionally for mortars, and is suitable for carpentry.

Shade or shelter:  In Nigeria the tree is planted for shade.

Tannin or dyestuff:  The leaves of D. edulis contain a dye.

Lipids:  The wood contains an oil that on petrol-ether extraction has been found to be composed of fatty acids and their esters. The fresh pulp is rich in lipids (35-65%) with a considerable amount of palmitic and linoleic acid. The tree can produce 7-8 t/ha of oil.

Medicine:  A perennial cure for a variety of ailments, ranging from ear infection to fevers and oral problems. In Nigeria the resin is used for treating parasitic skin diseases and jiggers. Pulped bark is used to cicatrize wounds. In the Democratic Republic of Congo, a bark decoction is used for gargle and mouthwash and for tonsillitis. It is taken in a powdered form with maleguetta pepper as an anti-dysenteric and for anaemia and for spitting blood and as an emmenagogue. With palm oil, it is applied topically to relieve general pains and stiffness and to treat cutaneous conditions. A decoction of the root bark is taken for leprosy. In the Democratic Republic of Congo, the leaves are eaten raw with kola nut as an anti-emetic. Leaf sap is instilled into the ear for ear problems, and a leaf decoction is prepared as a vapour bath for feverish stiffness with headache.

Gum or resin:  The bark is aromatic; on injury, it yields a resin that is used as pitch on calabashes and for mending earthenware. It can be burnt as a primitive lamp oil or bush candle.

Ornamental:  Because of its rythmical growth process and the colour of young leaves, the plum tree can be used as an ornamental during the first ages. It is therefore often found as a garden tree in and around villages.

Soil improver: Leaves and the remains of the fruits can provide considerable quantities of biomass to improve soil fertility. Research carried out in the forest humid lowland of south Cameroon, showed that the peasant farmers use the tree as a good indicator of soils fertility.

Intercropping: The plant canopy can allow its integration into the traditional farming systems involving food crops, mainly shade tolerant species such as Xanthosoma saggittifolium, Colocosia esculenta etc. The double revolution of the African plum tree in the forest zone of Cameroon which doesn’t necessarily go together with the flowering of the food crops, leads to a progressive harvesting during the year. The tree is usually grown to provide shade, mainly for perennial crops such as cocoa and coffee, in Nigeria.

Essential oil: Under steam distillation, the resin has been reported to yield a peppery essential oil rich in sabinene, beta-phellandrene and limonene.