The oil bean tree pentaclethra macrophylla

by Paul Latham

APICULTURAL VALUE

The nectar produced by flowers of this tree is very attractive to bees. Flowering continues over long periods when there is little other forage available.

Recommended for planting to increase honey production.

Family

Leguminosae (Mimosaceae)

Other names are Atta bean; Owala oil tree; Neganzi.

Other uses

The two main uses are for fuelwood and for ie edible seeds which are particularly liked in Nigeria. It makes good firewood but gives off an unpleasant smell. It is also used for charcoal The ash from the seed pods can be used as cooking salt. The seeds are edible after roasting or boiling for 12 hours. They yield 30-36% of oil which is rich in protein, and is suitable for making candles and soap. Flour from the seeds can be used for bread making.

The timber is also used It is reddish brown and very hard and difficult to work. It can be used for turnery and general carpentry. It is reputed to be resistant to termite, fungal and insect attack. The tree is the host plant of an edible caterpillar (Misendi, Kicongo).

Description

The tree grows to height of 21 and with girth up to 6 m, branching low down and forming spreading crown. The bole is crooked with low wide buttresses.

Bark: greyish to dark reddish brown, thin, flaking off in irregular patches; the slash is reddish orange.

Leaves: have stout, angular common stalk, 20-45 cm long covered with rusty stellate hairs and consist of 10-12 pairs of stout opposite pinnae There are 12-15 pairs of opposite, stalkless leaflets.

Flowers: are creamy yellow or pinkish white, sweet smelling, crowded in narrow spikes 7-20 cm long.

Pods: are very persistent, 35-45 cm long, hard and woody, splitting open explosively and curling up; containing about flat glossy brown seeds up to 7 cm long.

Flowering: January-May; July-December.

Distribution

The oil bean tree grows in tropical West Africa extending from Angola to Senegal.

Habitat

Grows at altitudes from 0-500 m in forest fallows and is sometimes planted. It prefers medium/loamy acid and well drained soil. Rainfall 1500-2700m.

Practical notes

The tree can be grown from stake cuttings, seedlings, direct sowing, or by budding. Shoot cuttings produce seed after four years. Budded trees fruit in three years. Normally in Zaire trees are planted from seed. The tree can be coppiced.

References

ICRAF Multipurpose tree and shrub database. ICRAF, Nairobi, Kenya.

Irvine, F R (1966) Woody plants of Ghana. Oxford University Press, Oxford, United Kingdom.

Keay, R W (1989) Trees of Nigeria. Oxford University Press, Oxford, United Kingdom.

Kibungu Kembelo (1995) Plantes Hates des Chenilles Commestibles. Jardin Botanique de Kisantu (Personal communication)