Cucumeropsis mannii (PROTA)

Plant Resources of Tropical Africa Introduction

List of species

General importance
Geographic coverage Africa
Geographic coverage World
Fruit
Vegetable oil
Timber
Forage / feed
Food security

distribution in Africa (wild and planted)

1, part of flowering stem; 2, fruit; 3, seeds. Redrawn and adapted by Iskak Syamsudin

fruiting plant habit

Seeds used as egusi. Cucumeropsis mannii, is at top right. Seeds at bottom right and top left both belong to Citrullus lanatus. Seeds at bottom left belong to a variety of Lagenaria siceraria from Côte d’Ivoire.

Cucumeropsis mannii Naudin

Protologue: Ann. Sci. Nat., sér. 5,5: 30 (1866).

Family: Cucurbitaceae

Chromosome number: 2n = 22

• Cucumeropsis edulis (Hook.f.) Cogn. (1881).

• Egusi-itoo, white seed melon, dark egusi (En).
• Egousi-itoo, égousi, gousi (Fr).
• Lipupu (Po).

Egusi-itoo occurs wild from Guinea Bissau east to southern Sudan and Uganda, and south to Angola. It is mostly cultivated in West Africa, especially in Nigeria, but occasionally also elsewhere, e.g. in Côte d’Ivoire, Cameroon and the Central African Republic. Egusi-itoo used to be very important as a seed vegetable in West Africa and parts of Central Africa at a time when there was plenty of forest to practise shifting cultivation. Now it is in strong decline, being replaced by egusi melon (Citrullus lanatus (Thunb.) Matsum. & Nakai).

Egusi-itoo is mainly grown for its oily seed. The seeds are prepared for consumption by parching and pounding to free the kernels of the seedcoat. The kernels are milled into a whitish paste which is used in soups and stews. The seeds (including seedcoat) are also roasted and served as a snack. They resemble groundnut in flavour.

An expensive semi-drying oil is extracted from the kernel, whereas the residue is fed to animals or used in the preparation of local snacks. The oil is suitable for cooking, soap making and, less commonly, illumination. It can readily be refined into superior products for table use. It is of better quality and higher value than cottonseed oil. The flesh of the fruit, though edible, is not commonly eaten.

In Ghana the fruit juice mixed with other ingredients is applied to the navel of newborn babies to accelerate the healing process until the cord-relics drop off. Macerated leaves are used in Gabon for purging constipated suckling babies. In Sierra Leone cattle boys traditionally use the dried fruit-shell of an egusi-itoo type with small elongated fruits as a warning horn.

Egusi-itoo is regarded as the original indigenous egusi melon in West and Central Africa and the seed can be found in most markets in the region. In Nigeria the demand for the seeds, particularly in the towns, led to large-scale planting. Although its production is declining, egusi-itoo still is a common article in the markets. The trade is mostly local. Export occurs from Côte d’lvoire to Nigeria, but the quantities involved are not reported.

The nutritional composition of egusi-itoo seed per 100 g is: water 8.3 g, energy 2282 kJ (545 kcal), protein 26.2 g, fat 47.3 g, carbohydrate 14.2 g, fibre 4.0 g, Ca 86 mg (Leung, W.-T.W., Busson, F. & Jardin, C., 1968). The seeds are rich in niacin (14.3 mg/100 g). The oil content of the kernel is 44% by weight. A sample of egusi-itoo seed oil from Côte d’lvoire consisted of linoleic acid 64.9%, oleic acid 12.4%, stearic acid 11.8% and palmitic acid 10.9%.

Egusi-itoo is replaced in many regions by egusi melon (Citrullus lanatus).

• Monoecious scandent herb up to 5(–10) m long, climbing by simple tendrils; stem angular, sparsely hairy.
• Leaves alternate, simple; stipules absent; petiole 2–12(–15) cm long, initially hairy but glabrescent; blade broadly ovate in outline, (6–)9–18(–21) cm × 7–15(–21) cm, deeply cordate at base, pentagonal to palmately 3–5-lobed with triangular to ovate lobes, margin sinuate-toothed, sparsely hairy on the veins, scabrid-punctate, palmately veined.
• Flowers unisexual, regular, 5-merous, yellow; calyx campanulate, lobes up to 6 mm × 1.5 mm; corolla with lobes shortly united at base; male flowers in an axillary raceme, often umbel-like, pedicel up to 2 cm long, corolla lobes up to 7 mm × 5 mm, with 3 free stamens almost lacking filaments; female flowers solitary in leaf axils, pedicel up to 5 cm long, corolla lobes up to 11 mm × 6 mm, with inferior, fusiform, 1-celled ovary, style columnar, stigmas 3, 2-lobed.
• Fruit an ellipsoid to obovoid berry 17–25 cm × 8–18 cm, green to pale yellow or creamy white, mottled, glossy, flesh white, many-seeded. Seeds obovate, flattened, 1–2 cm × 0.5–1 cm, smooth, white.
• Seedling with epigeal germination; cotyledons leafy, elliptical.

Cucumeropsis comprises a single species. It belongs to the tribe Melothrieae, together with Cucumis.

In West Africa egusi-itoo is usually planted in March–May at the start of the rainy season and harvested 6–8 months later (September–December). The crop requires support and is commonly found at the edge of gardens, climbing into shrubs or trees. When grown in shifting cultivation, debris left after burning serves as support. Egusi-itoo does not do well in the open or on flat land.

Egusi-itoo occurs in forest, often at the margin or in openings, but also in swamp forest, more humid savanna and abandoned fields, up to 1150 m altitude.

At the beginning of the rainy season 3–4 seeds per hole are sown. The 1000-seed weight is (150–)220–250 g. Seedlings usually appear within 6–8 days. Egusi-itoo is often grown between other crops, growing on stakes along with yam or supported by a strong trellis of at least 1 m tall.

Egusi-itoo is still mainly collected from wild stands, which are often retained when clearing fields. In cultivation it requires a soil rich in manure or partially decomposed organic matter. Application of N and K fertilizer can increase yields considerably, but P fertilizer has shown little effect.

In Nigeria a severe damping-off disease caused by Macrophomina phaseolina has been reported. The fruits are sometimes attacked by the fruit fly Dacus punctifrons. The larvae develop in the fruit and eventually cause rot. Fruit flies attack fruits at every stage of development and can severely affect production. The pupae are found in the soil and it is therefore advised not to plant in the same field the following year. The aphid-like flea hopper Halticus tibialis may suck sap from the leaves; young leaves become wrinkled, older ones become swollen around the sucking holes and later die. Several other pests attacking cucurbits are also found on egusi-itoo.

Seed of egusi-itoo stored in open jars may be seriously damaged by beetles within a few weeks of storage; these have been identified as Triboleum castaneum and Lasioderma serricorne, and are also found in dried okra (Abelmoschus spp.) and roselle (Hibiscus sabdariffa L.) fruits.

Fruits are collected when the stems have dried and fruits have changed colour from green to creamy white or yellow.

Under extensive management, where egusi-itoo is planted around remaining trunks of trees, seed yield is about 300 kg/ha. In more intensive cropping systems, where land has been cleared and burnt before cultivation, it may reach 900 kg/ha. A plant usually produces 2–5 fruits; each fruit weighs 0.8–1.8 kg and contains 90–400 seeds (up to 100 g).

After collection, fruits are cracked or split open; they are then placed in a heap or pit and are left for 14–20 days to let the fruit pulp rot. During this period a strong pungent smell is produced and this explains why seed extraction takes place at a distance from the homestead. Then the seeds are removed and thoroughly washed to remove thick mucilage covering them; next they are covered with sand or ash to prevent sticking, which would make hulling difficult. The seeds are dried to about 10% moisture content before packing. Packaging must be thorough and packs must be stored away from moisture, as seeds otherwise may germinate. Hulling is facilitated by heating to 60ºC. The weight of decorticated seed is about 60% of the whole dry seed. The kernels are milled and used as a vegetable or for producing vegetable oil for domestic use. Processing the seed of egusi-itoo is time consuming and labour intensive; this is one of the reasons why it has been partly replaced by egusi melon.

Germplasm of several Cucurbitaceae species used as seed vegetable, including Cucumeropsis mannii, is being maintained at the genebank of the National Centre for Genetic Resources and Biodiversity (NACGRAB), Ibadan, Nigeria.

Unless the seed yield of egusi-itoo can be increased and its crop management and seed processing can be simplified, it seems likely that its replacement by cultivars of egusi melon will continue, although specialty markets may develop.

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• Busson, F., 1965. Plantes alimentaires de l’ouest Africain: étude botanique, biologique et chimique. Leconte, Marseille, France. 568 pp.

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• Ladipo, D.O., Sarumi, M.B., Adewusi, H.G. & Adebisi, A.A., 1999. ‘Egusi’ diversity in Nigeria. A commissioned survey report submitted to IPGRI-SSA. IPGRI, Rome, Italy.

• Raponda-Walker, A. & Sillans, R., 1961. Les plantes utiles du Gabon. Paul Lechevalier, Paris, France. 614 pp.

• Jeffrey, C., 1967. Cucurbitaceae. In: Milne-Redhead, E. & Polhill, R.M. (Editors). Flora of Tropical East Africa. Crown Agents for Oversea Governments and Administrations, London, United Kingdom. 157 pp.

• Stevels, J.M.C., 1990. Légumes traditionnels du Cameroun: une étude agrobotanique. Wageningen Agricultural University Papers 90–1. Wageningen Agricultural University, Wageningen, Netherlands. 262 pp.

• J.K. Egunjobi, University of Ibadan, P.O. Box 22675, Ibadan, Nigeria

• A.A. Adebisi, Centre for Environment, Renewable Natural Resources Management, Research and Development (CENRAD), P.M.B. 5052, Jericho Hills, Ibadan, Nigeria

Egunjobi, J.K. & Adebisi, A.A., 2004. Cucumeropsis mannii Naudin. [Internet] Record from PROTA4U. Grubben, G.J.H. & Denton, O.A. (Editors). PROTA (Plant Resources of Tropical Africa / Ressources végétales de l’Afrique tropicale), Wageningen, Netherlands.

Accessed 3 April 2025.