Africa is home to a variety of nut trees, each with unique characteristics and uses. These trees not only provide essential nutrients but also play a significant role in the economic and cultural lives of local communities. This article explores some of the most important African nut trees, including *Coula edulis* (Gabon nut), *Plukenetia conophora* (Nigerian walnut), *Vitellaria paradoxa* (shea nut), and *Irvingia gabonensis* (dika nut).
Coula edulis: The Gabon Nut
*Coula edulis* is a tree native to tropical western Africa, stretching from Sierra Leone to Angola. This evergreen tree can reach heights of 25-38 meters (82-125 ft) and has a dense crown that provides ample shade. The primary edible product of the tree is the Gabon nut, an ellipsoidal drupe that is green or red and approximately 1-2 inches long.
The nut has a pleasant taste and can be consumed raw, grilled, or boiled. In addition to being a food source, the nut is rich in nutrients, vitamins, and minerals such as potassium, calcium, and magnesium, as well as fatty acids. The tree's leaves and bark are also used in traditional medicine to treat respiratory and coronary illnesses. Its fibrous wood is useful for construction purposes, making it a multi-purpose tree.
*Coula edulis* is an extremely productive tree, yielding 50-100 kg of fruit per year, depending on the climate. However, it requires well-draining soil and is sensitive to waterlogging. In colder climates, it may be necessary to bring the plants indoors during winter months if temperatures drop below freezing.
Coula edulis fruit
Plukenetia conophora: The Nigerian Walnut
*Plukenetia conophora*, also known as the Nigerian walnut or conophore, is a climbing shrub native to tropical western and central Africa, from Togo to Congo and Sierra Leone. Despite its name, it is not related to the walnut but bears a superficial resemblance to it. It is abundant in Nigeria, Cameroon, the Republic of the Congo, and the Democratic Republic of Congo.
Read also: Handling African Milk Tree Sap
This species prefers rain-forest hedges in half-shady places, low bush, secondary forests, and plantations at elevations from 250-1,400 m (820-4,590 ft). Although well-recorded in Sierra Leone, it is believed to have been introduced by returning slaves, as it is known by its Yoruba (Nigerian) name.
*Plukenetia conophora* produces stems that are usually 3-15 m (9.8-49.2 ft) long, though they can reach up to 30 m (98 ft). The seed is thin-shelled and about 25 mm (0.98 in) long, contained in a pod that may house one, two, or three shelled nuts. The walnut shells can be black or brown, and the nut is whitish upon cracking.
This plant is widely cultivated for its nuts, which are cooked and consumed as snacks, often served with corn or rice. In West Africa, especially in Nigeria and Sierra Leone, as well as in Central African countries such as Cameroon, the seeds provide income to rural people, thereby improving their economy. The seed can be ground into a powder and used with flour in making cakes. The nuts can also be roasted and eaten in the general diet or added to cakes.
The nuts are oil-bearing, yielding 48-60% of a light golden-colored oil with a taste resembling linseed oil.
How to eat your fresh picked Sacha inchi - Plukenetia volubilis
Vitellaria paradoxa: The Shea Nut Tree
The shea nut tree (*Vitellaria paradoxa*) is a widely distributed and traditional source of vegetable fat in the Sahel region, which stretches from Senegal to Ethiopia. Common names include bambouk butter tree, galam butter tree, and arbre à beurre. Fruity pulp and butter from shea nut trees are important food sources during the ‘hunger months’ of the early rainy season, before annual crops are harvested.
Read also: Learn About African Milk Trees
For centuries, farmers in the Sahel have preserved shea nut trees when clearing cropland. In addition to valuable edible fat, the trees provide edible flowers and bee forage, and parts of the tree can be used medicinally. Farmers also appreciate shea nut trees for their termite-resistant wood and their ability to survive severe droughts and brush fires.
Shea trees provide shade for livestock and act as a windscreen to reduce erosion and crop damage. These trees reproduce naturally and grow slowly, reaching a height of up to 20 m and a trunk diameter up to one meter. They grow in areas with annual rainfall between 400 and 1,800 mm and can survive multi-year droughts.
Shea nut fruits
A shea nut tree will start producing fruit after 15 to 20 years, reach full production at 40 to 50 years, and can live as long as 400 years. Flowers bloom during the dry season and provide nectar for honey bees. The inner seed or nut has a smooth, thin, brown outer covering that protects the nutritious kernel. The nutmeats can be eaten fresh or roasted like almonds or processed to remove the butter.
Shea butter is rich in Vitamins D, E, and K, and is a good source of calcium and potassium. Its mono-unsaturated fatty acid profile is similar to olive and canola oils. Shea butter has been exported to Europe for over a century and is used as an ingredient in chocolate and as a substitute for cocoa butter. Its moisturizing qualities make it popular in cosmetics and hair and skin care products.
The demand for high-quality shea butter has led to relatively high commodity prices, spurring international development agencies and fair trade organizations to work with rural women in creating poverty alleviation initiatives based on this ancient cottage industry.
Read also: Explore African Trees
Shea nuts
Irvingia gabonensis: The Dika Nut Tree
*Irvingia gabonensis*, commonly known as Dika Nut, is a large, evergreen tree that grows about 40 m in height with a straight bole of up to 100 cm in diameter. It is found in tropical Africa and is highly valued for multiple uses. One of which is the edible seeds used in soups and as a food flavoring. The seed is also used for the preparation of odika, also known as dika bread or Gabon chocolate.
The fruits are yellow and fibrous, with palatable pulp that can be used for fruit drinks and jams. The pulp is also used to prepare a black dye for cloth. Dika nut also has medicinal uses. Its bark is a purgative for treating gastrointestinal and liver conditions, sterility, hernias, and urethral discharge. It is also an aphrodisiac and used in the treatment of diarrhea and dysentery, body pains, toothache, sores, and wounds.
The tree is commonly preserved on farms to provide shade for crops, especially cocoa and coffee. The wood is tough, very heavy, very hard, durable, and resistant to termite attack. The kernel is an important source of vegetable oil, with a total fat content recorded as 54 - 68%. The crude dika paste yields on heating or boiling 70 - 80% of a pale yellow or nearly white solid fat, dika butter, which has qualities comparable with cacao-butter.
In season, the fallen fruits are collected in the forest and stacked till the pulp has rotted away. The nuts are opened and the cotyledons removed and dried. These cotyledons are a common item of market produce and are used in soups and as a food flavouring. They are said to have a pleasant taste with a lingering slight bitterness.
Different preparations of the seed are common. For odika, the cotyledons are ground and heated in a pot that is lined with banana leaves in order to melt the fat, and then left to cool. Pepper and other spices may be added, and it may perhaps be subjected to wood smoke.
The end product may be made up into cylindrical packets wrapped in a basket-like or leaf-wrapping. It can be kept for a long time without going off and it is used as a food-seasoner.
Irvingia gabonensis fruit
Comparative Table of African Nut Trees
Here is a comparative table summarizing the key aspects of the African nut trees discussed:
| Tree Name | Native Region | Edible Parts | Uses | Special Features |
|---|---|---|---|---|
| *Coula edulis* (Gabon Nut) | Tropical Western Africa | Nut | Food, traditional medicine, construction | Sensitive to waterlogging |
| *Plukenetia conophora* (Nigerian Walnut) | Tropical Western and Central Africa | Nuts, Seeds | Snacks, cooking oil, cakes, income generation | Climbing shrub |
| *Vitellaria paradoxa* (Shea Nut) | Sahel Region | Nuts, Flowers | Food, cosmetics, traditional medicine | Drought-resistant |
| *Irvingia gabonensis* (Dika Nut) | Tropical Africa | Seeds, Fruit | Soups, flavorings, jams, dyes, medicine | Termite-resistant wood |
