Trichilia emetica

Trichilia emetica is a tree in the family Meliaceae, commonly known as the Natal mahogany. It is an evergreen tree, with handsome glossy dark green leaves and a wide spreading crown. Its sweet-scented flowers attract bees and birds.

Description

A large tree. It is evergreen. It grows 8-20 m high. The crown is round and widespreading. The leaves have 4-5 pairs of leaflets and one at the end. They are oblong and 12 cm long by 5.5 cm wide. They are dark green and glossy above and have short hairs underneath. The leaf stalk is 7-12 cm long. The flowers are creamy-green. The petals are 1.6 cm long. They occur in sort branched heads in the axils of leaves. These are about 5 cm long. The fruit is an almost round creamy-brown capsule. It is 2.5-3 cm across. They split into 2-3 valves. The seeds are black and covered with a red seed coat (aril).

Edible Uses

A sweet, milky, drinkable liquid is extracted from the arils. The fleshy seed envelope can be chewed as a substitute for kola. Skinned seeds may be eaten raw or soaked in water and ground, with the resulting liquid mixed into spinach dishes. The seedcoat is poisonous and must be removed. An edible oil is obtained from the fleshy seed envelope (the sarcotesta) by squeezing the seeds in water; the resulting fatty suspension is used for cooking. Oil extracted from the seed kernel itself is not edible due to its excessive bitterness.

Traditional Uses

CAUTION: The seeds are reported to be poisonous. The oil extracted from the seeds, without the coat, is used. Hot water is poured over the seeds and they are left to soak for a few hours then rubbed between the hands. A sweet milky liquid is extracted from the layer around the seeds. It is used as a drink or added to food. The flesh of the fruit is eaten. The fleshy layer or aril around the seeds is separated from the seeds, are soaked and cooked with sweet potato or squash.

Medicinal Uses

The leaves can be used as an antidote for irritation caused by the buffalo bean. Bark is used to treat pneumonia. A macerate of the root bark treats epilepsy and leprosy. Pieces or powdered bark soaked in warm water are used as an emetic or enema for intestinal ailments — only in small doses, as the effect can be violent. The bark also treats skin complaints. The roots are purgative and are used for colds, infertility and inducing labour in pregnant women. Powdered root treats cirrhosis, river blindness, ascariasis and dysmenorrhoea. A combined bark and root decoction addresses colds, pneumonia and intestinal disorders including hepatitis. A bitter medicinal oil, made by boiling ground seed in water, is taken orally to relieve rheumatism. Applied externally, the oil treats leprosy, sores, ringworm, other parasites and skin diseases.

Known Hazards

The seed coat is extremely poisonous. The seeds are poisonous and the poisonous compounds seem to be concentrated in the seedcoat.

Distribution

A tropical plant. It grows at medium to low altitudes in forests along rivers and near the coast. In East Africa it grows from sea level to 1,835 m altitude. In West Africa it grows in the savannah. It grows in areas with a rainfall above 550 mm. It can tolerate drought. It cannot tolerate frost. It can grow in arid places.

Where It Grows

Africa, Benin, Botswana, Burkina Faso, Cameroon, Cape Verde, Central Africa, Chad, Congo, East Africa, Eritrea, Eswatini, Ethiopia, Ghana, Guinea, Guinée, Guinea-Bissau, Kenya, Liberia, Malawi, Mali, Middle East, Mozambique, Namibia, Nigeria, Saudi Arabia, Senegal, Somalia, South Africa, Southern Africa, Sudan, Swaziland, Tanzania, Uganda, West Africa, Yemen, Zambia, Zimbabwe,

Cultivation

It grows best in areas where annual daytime temperatures fall within the range 19 - 31°c. It prefers a mean annual rainfall in the range 600 - 2,300mm. Succeeds in sun or shade. Prefers a well-drained, rich alluvial or sandy soil and a high water table. Established plants are very drought tolerant. A fast-growing species, increasing in height by up to 1 metre a year in colder areas and 2 metres in warmer areas. Under optimal conditions trees start producing fruit when 6 - 8 years old. Seed yields of individual trees vary greatly per tree and per year and range from 20 - 180 kg/year, averaging 45 - 65 kg. The tree responds well to coppicing and also produces suckers. A dioecious species, both male and female forms need to be grown if fruit and seed are required. It is able to tolerate moderate winter drought and slight frost.

Propagation

Seed is best sown as soon as it is ripe. Remove the surrounding aril by macerating the seed in water, then sow immediately — either directly in situ or into nursery bags. Germination typically occurs within 10–20 days, and seedlings can be planted out 6–8 months later. Propagation is also possible from cuttings taken from one-year-old coppice shoots, by layering, or from root suckers.

Other Uses

The plant assists significantly in soil conservation and is widely planted as a windbreak in urban and rural areas, and used in reforestation projects. The pressed seedcake remaining after oil extraction has an approximate protein content of 16% and is suitable as a fertiliser. The plant is regarded as an indicator of areas with palatable grass species. Two distinct oils come from the seed: the oil from the fleshy seed envelope, known as Mafura oil, is edible and produces a good finish on wood surfaces; the oil from the kernel, called Mafura butter, is too bitter to eat and is used for making candles. Commercially, both oils are often extracted together. The fleshy envelope contains 14–51% oil; the kernel contains 68% oil. Combined, the oils are excellent for soap-making and are sometimes used as a cosmetic or for preserving foodstuffs. The leaves can be used as soap, and aqueous leaf extracts show pronounced antifungal properties against several plant pathogens. Crushed seed mixed at a dosage of 1% almost completely protected cowpea seed from storage pests. A pinkish dye is obtained from the bark. The wood is used as chewsticks for oral hygiene. The wood is typically pinkish with little distinction between sapwood and heartwood — soft, light yet firm, and works well. It is vulnerable to borers and should be treated accordingly. It produces attractive furniture that darkens with oil, and is good for shelving, carvings, musical instruments, household articles, tool handles and spears. Trees with long, straight trunks are traditionally used for dugout canoes. The wood is widely used as fuel.

Production

It is fast growing. In Tanzania fruit can be collected from April to July and November to December. Dried seeds can be stored for several months.

Other Information

It is a commonly used fruit in Mozambique. Seed are sold commercially.

Nutrition

Synonyms

Also Known As

Bitterwood, Bululu, Chipindura, Cucho, Dipugedi, Ixolo, Mafura, Mafurreira, Marba, Mchekeri, Mchengo, Mchenya, Mkhudlu, Mnwamaji, Moboba, Mothothwan, Mothowani, Movava, Mshunguti, Msichici, Msikidzi, Msikitsi, Mtutu, Muchichiri, Munyantse, Mururi, Musikili, Musukidi, Mutshikili, Muwamaji, Mutuhu, Muzaramanga, Ndilolo, Nkuhlu, Pilivili, Roka, Rooiessenhout, Tihuhlu, Tinkuhlu, Umkhuhlu, Umsikili, Umtshitshivi, Vungu

References (56)

• Abbiw, D.K., 1990, Useful Plants of Ghana. West African uses of wild and cultivated plants. Intermediate Technology Publications and the Royal Botanic Gardens, Kew. p 48
• Allen, D. J., 2007, Wildflowers and Common Trees of East Africa. Camerapix Publishers p 128
• Bekele-Tesemma A., Birnie, A., & Tengnas, B., 1993, Useful Trees and Shrubs for Ethiopia. Regional Soil Conservation Unit. Technical Handbook No 5. p 436
• Boll. Soc. Bot. Ital. 1923:115. 1923 (Trichilia roka)
• Bonou, A., et al, 2013, Valeur economique des Produits Forestiers Non Ligneux (PFNL) au Benin. Editions Universitaires Europeennes p 91

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