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Pentaclethra macrophylla - Benth.

Common Name African Oil Bean. Oil Bean Tree, Owala Oil
Family Fabaceae
USDA hardiness 10-12
Known Hazards The seeds contain a toxic alkaloid[317 ]. They are pulverized and used as a component of an arrow poison, they are also used as fish poison and as mild drug (snuff)[317 ].
Habitats Mainly in lowland rainforest, but also sometimes in the high forest zone[303 ]. Often occurs near streams and on the edges of damp depressions, and is frequently seen as a small tree of untidy habit and large crown on roadsides and farms[303 ].
Range West tropical Africa - Senegal to Central African Republic, south to Angola and the Congo.
Edibility Rating    (3 of 5)
Other Uses    (3 of 5)
Weed Potential No
Medicinal Rating    (2 of 5)
Care (info)
Tender Moist Soil Semi-shade Full sun
Pentaclethra macrophylla African Oil Bean. Oil Bean Tree, Owala Oil

Pentaclethra macrophylla African Oil Bean. Oil Bean Tree, Owala Oil
wikimedia.org / Maša Sinreih in Valentina Vivod


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Physical Characteristics

 icon of manicon of cone
Pentaclethra macrophylla is an evergreen Tree growing to 30 m (98ft) by 30 m (98ft) at a fast rate.
See above for USDA hardiness. It is hardy to UK zone 10. The flowers are pollinated by Bees.
It can fix Nitrogen.
Suitable for: medium (loamy) and heavy (clay) soils and prefers well-drained soil. Suitable pH: mildly acid and neutral soils and can grow in very acid soils.
It can grow in semi-shade (light woodland) or no shade. It prefers moist soil.

UK Hardiness Map US Hardiness Map


No synonyms are recorded for this name.

Plant Habitats

Edible Uses

Edible Parts: Oil  Seed  Seedpod
Edible Uses: Oil  Salt

Seeds - boiled or roasted[46 , 299 , 418 ]. They can be ground into a flour and used in making bread[46 ]. The pods are 40 - 50cm long and 5 - 10cm wide, containing 6 - 10 flat, glossy brown seeds up to 7cm long[414 , 418 ]. The seeds are fermented to produce 'ugba'[299 ]. They are boiled for 3 - 12 hours; then the seedcoat is removed. When the cotyledons are cooled to room temperature they are sliced into small pieces of 4 - 5 cm × 1 - 2 mm and washed with water. The slices are boiled for 1 - 2 hours, cooled and soaked in water for 10 hours[299 ]. Then the slices are drained in a basket lined with banana leaves[299 ]. The drained slices are wrapped in blanched leaves of banana or Mallotus oppositifolius and incubated at ambient temperature for 4 - 6 days when prepared for use as a snack or sidedish, or for 7 - 10 days when prepared as a condiment for soups[299 ]. The fermentation is proteolytic and proceeds under alkaline conditions. It is caused mainly by Bacillus subtilis, but other Bacillus spp. are also involved, while other bacteria may be present as contaminants[299 ]. The seeds contain 30 - 36% of an edible oil[317 ]. They are used for the production of 'owala-oil', or 'owala-butter' which is used in food[317 ]. The ash of the seedpods is used as a salt substitute[414 ].

References   More on Edible Uses

Medicinal Uses

Plants For A Future can not take any responsibility for any adverse effects from the use of plants. Always seek advice from a professional before using a plant medicinally.
Abortifacient  Analgesic  Anthelmintic  Antidiarrhoeal  Antiinflammatory  Dysentery  Laxative  Skin

Extracts of the leaf, stembark, seed and fruit pulp have anti-inflammatory and anthelmintic activity, and are used to treat gonorrhoea and convulsions, and also used as analgesic[299 ]. The crushed seeds are taken to acquire an abortion[418 ]. Leaf and stem decoctions are taken against diarrhoea[418 ]. A lotion made from the bark is used as a wash on sores[46 ]. The ripe fruits are applied externally to heal wounds[299 ]. The root bark is used as a laxative, as an enema against dysentery and as a liniment against itch[299 ]. An infusion of the bark is used as an abortifacient[299 ].

References   More on Medicinal Uses

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Other Uses

Beads  Charcoal  Fencing  Fuel  Lighting  Mordant  Mulch  Oil  Soap making  Soil conditioner  Wood

Agroforestry Uses: Farmers protect this species on farms because of its open crown form that allows substantial light and does not inhibit crop plants grown under its canopy[418 ]. This accounts for the trees use in combination with food crops on farms and particularly in home gardens in south east Nigeria[418 ]. The tree produces a heavy leaf fall and these are used as a mulch[414 ]. Other Uses: The seeds contain 30 - 36% oil[317 ]. They are used for the production of 'owala-oil', or 'owala-butter' which is used in soap and candle production[317 ]. The dried pods are used as fuel[418 ]. The ashes of burnt pods are used as a mordant[303 , 414 ]. The seeds are decorative and are used as beads in necklaces and rosaries[303 ]. The heartwood is reddish brown and not always distinctly demarcated from the whitish or grey sapwood[299 ]. The wood is hard, the grain interlocked and difficult to work[46 , 299 ]. Wood of suitable size can be difficult to find but, when available, it is used for turnery, wheelwright's work, fencing, railway sleepers and general carpentry[46 , 299 ]. Traditionally, it is used to make pestles and mortars[299 ]. The wood is used as firewood and charcoal[418 ]. Pentaclethra macrophylla nodulates and fixes atmospheric nitrogen.

Special Uses

Carbon Farming  Coppice  Food Forest  Nitrogen Fixer

References   More on Other Uses

Cultivation details

Agroforestry Services: Nitrogen  Management: Standard  Regional Crop  Staple Crop: Protein-oil

A plant of the humid and subhumid tropics[418 ]. It grows best in areas where the mean annual temperature is within the range 24 - 30°c, but can tolerate 18 - 34°c[418 ]. It prefers a mean annual rainfall in the range 1,800 - 2,200mm, tolerating 1,000 - 2,700mm[418 ]. Succeeds in full sun and in light shade[418 ]. Prefers a deep, moderately fertile medium soil[418 ]. Tolerant of some water-logging[414 ]. Prefers a pH in the range 4.5 - 5.5, but tolerates 4 - 6.5[418 ]. Seedling trees can reach a height of 1.5 metres by the end of their first year[414 ]. The trees start to produce beans from their tenth year and will continue to bear regularly[418 ]. After about 2-years growth in the forest, the trees become relatively fire resistant and resprout readily when lopped[414 ]. Trees coppice well and often produce watershoots around their base[299 ]. There are conflicting reports on whether or not this tree has a symbiotic relationship with certain soil bacteria, so it is unclear as to whether this tree fixes atmospheric nitrogen[755 ].

Carbon Farming

  • Agroforestry Services: Nitrogen  Plants that contribute to nitrogen fixation include the legume family – Fabaceae.
  • Management: Standard  Plants grow to their standard height. Harvest fruit, seeds, or other products. Non-Destructive management systems.
  • Regional Crop  These crops have been domesticated and cultivated regionally but have not been adopted elsewhere and are typically not traded globally, Examples in this broad category include perennial cottons and many nuts and staple fruits.
  • Staple Crop: Protein-oil  (16+ percent protein, 16+ percent oil). Annuals include soybeans, peanuts, sunflower seeds. Perennials include seeds, beans, nuts, and fruits such as almond, Brazil nut, pistachio, walnut, hazel, and safou.

References   Carbon Farming Information and Carbon Sequestration Information

Temperature Converter

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Plant Propagation

Seed - best sown as soon as it is ripe because it has a short viability[414 ]. Storage at 15°c can extend longevity for about three months[414 ]. Scarifying the seed and then soaking for 24 hours in warm water prior to sowing increases the germination rate and reduces the time taken to germinate[414 ]. About 87% of treated seed germinates within 14 - 16 days[303 ]. Adult trees can be air layered[414 ]. Cuttings of juvenile plants can be rooted, but usually require rooting hormone[414 ].

Other Names

If available other names are mentioned here

African oil bean, An-fal, Apara, Arvore-das-mares, Ataa, Atawa, Atta Bean, Bemba, Benguele, Bgangban, Biague, Bobala, Bowala, Cheboe, Cherbou, Congo acacia, Coquenguer, Ebaye, Ebe, Essiri, Fa-wuli, Faa, Fakha, Fawei, Gbau, Kombolo, Marrone, Mbalaka, Mubala, N'tantass, Nganzi, Okpagha, Opachalo, Otshakula, Ovala, Owala oil tree, Pao-di-godre, Sindjam-djane, Sucupira, Uaua, Ugba, Ukana, Ukelede, arbre à semelles, acacia du Congo (Fr).

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Found In

Countries where the plant has been found are listed here if the information is available

Africa, Angola, Benin, Cameroon, Central Africa, Central African Republic, CAR, Congo DR, Congo R, Côte d'Ivoire, Equatorial-Guinea, Gabon, Gambia, Ghana, Guinea, Guinée, Guinea-Bissau, Ivory Coast, Liberia, Niger, Nigeria, Sao Tome and Principe, Senegal, Sierra Leone, Sudan, Togo, West Africa

Weed Potential

Right plant wrong place. We are currently updating this section. Please note that a plant may be invasive in one area but may not in your area so it’s worth checking.

None Known

Conservation Status

IUCN Red List of Threatened Plants Status : This taxon has not yet been assessed

Related Plants
Latin NameCommon NameHabitHeightHardinessGrowthSoilShadeMoistureEdibleMedicinalOther

Growth: S = slow M = medium F = fast. Soil: L = light (sandy) M = medium H = heavy (clay). pH: A = acid N = neutral B = basic (alkaline). Shade: F = full shade S = semi-shade N = no shade. Moisture: D = dry M = Moist We = wet Wa = water.


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Links / References

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A special thanks to Ken Fern for some of the information used on this page.

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