Cucumis africanus (PROTA)

Plant Resources of Tropical Africa Introduction

List of species

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

Cucumis africanus L.f.

Protologue: Suppl. pl.: 423 (1781).

Family: Cucurbitaceae

Chromosome number: 2n = 24

Synonyms

• Cucumis hookeri Naudin (1870).

Origin and geographic distribution

Cucumis africanus occurs in Angola, Namibia, Botswana and South Africa. It is also found in Madagascar, where it probably has been introduced.

Uses

The leaves of Cucumis africanus are eaten as a cooked vegetable by many tribes in its area of origin. Non-bitter fruits serve as a source of water and are eaten as a vegetable. In Madagascar only the fruits are eaten.

Properties

The leaves contain per 100 g: water 92.2 g, protein 1.3 g, fat 0.3 g, carbohydrate 3.4 g, fibre 1.2 g, Ca 216 mg, Mg 175 mg, P 11 mg, Fe 12 mg, thiamin 0.02 mg, riboflavin 0.11 mg, niacin 0.34 mg and ascorbic acid 81 mg. The fruits contain per 100 g: water 88.2 g, protein 2.8 g, fat 1.6 g, carbohydrate 3.3 g, fibre 2.9 g, Ca 13 mg, Mg 29 mg, P 20 mg, Fe 1.1 mg, thiamin 0.2 mg, riboflavin 0.03 mg, niacin 0.84 mg and ascorbic acid 13 mg (Arnold, T.H., Wells, M.J. & Wehmeyer, A.S., 1985).

Plants with non-bitter, large and oblong fruits occur wild in Angola, Namibia and South Africa. The smaller, ellipsoid fruits found in other Cucumis africanus types are bitter, possibly poisonous and unsuitable for consumption. A third type, intermediate in taste and shape, seems to exist as well.

The fruit of Cucumis africanus contains considerable amounts of cucurbitacin A, B and D and traces of cucurbitacin G and H. Cucurbitacins, which are known from many Cucurbitaceae and various other plant species, exhibit cytotoxicity (including antitumour activity), anti-inflammatory and analgesic activities.

Description

• Annual, monoecious, prostrate or scandent herb, sometimes with woody, thickened roots, stems up to 1 m long; tendrils simple.
• Leaves alternate, simple; stipules absent; petiole 1–1.5 cm long; blade ovate, deeply palmately (3–)5-lobed, 1.6–8.2 cm × 1.8–7 cm, cordate at base, lobes elliptical, broadly elliptical to ovate-elliptical.
• Flowers unisexual, regular, 5-merous; receptacle 3–5 mm long; sepals 1.5–3 mm long; petals bright yellow, 5–11 mm long; male flowers 1–5 together in small fascicles, with pedicel up to 1 cm long, stamens 3; female flowers solitary, with pedicel 1–4 cm long, ovary inferior, densely softly spiny.
• Fruit an ellipsoid to oblong-ellipsoid berry 3–9 cm × 2–4.5 cm, when ripe strongly longitudinally striped pale greenish-white and purplish-brown, with spines 3–6 mm long; fruit stalk 2–4.5 cm long, slender, not expanded upwards.
• Seeds ellipsoid, compressed, 4–7 mm × 2–3.8 mm × 1–1.2 mm.

The genus Cucumis includes about 30 species, 4 of which are economically important: cucumber (Cucumis sativus L.), melon and snake cucumber (Cucumis melo L.), West Indian gherkin (Cucumis anguria L.) and horned melon (Cucumis metuliferus Naudin). Cucumis africanus is placed in the ‘anguria’ group of the subgenus Melo. Literature, especially the older literature, should be interpreted with caution as other Cucumis species have often been misidentified as Cucumis africanus.

In Madagascar Cucumis africanus flowers from January to June.

Ecology

Cucumis africanus occurs in dry bushland. In Madagascar it is restricted to areas close to habitation.

Management

Leaves and fruits are collected from the wild. In Madagascar the fruits are collected from semi-wild plants.

Genetic resources

Cucumis africanus is not uncommon in its area of origin and hence is not threatened with genetic erosion or extinction. Cucumis africanus germplasm is stored in the United States, United Kingdom, the Czech Republic and Spain.

Within the ‘anguria’ group of about 16 spiny-fruited Cucumis species to which Cucumis anguria belongs as well, there seem to be no major barriers to gene exchange. Several interspecific crosses have been made in this group. An intermediate response to downy mildew (Pseudoperonospora cubensis) has been reported for Cucumis africanus.

Prospects

In southern Africa Cucumis africanus is considered to have potential for domestication. The variation within the species will allow successful breeding and selection. Breeders’ interest will focus on disease resistance within the scope of gene transfer to the economically important Cucumis species.

Major references

• Arnold, T.H., Wells, M.J. & Wehmeyer, A.S., 1985. Khoisan food plants: taxa with potential for future economic exploitation. In: Wickens, G.E., Goodin, J.R. & Field, D.V. (Editors). Plants for arid lands. Proceedings of the Kew international conference on economic plants for arid lands. Allen & Unwin, London, United Kingdom. pp. 69–86.

• Jeffrey, C., 1978. Cucurbitaceae. In: Launert, E. (Editor). Flora Zambesiaca. Volume 4. Flora Zambesiaca Managing Committee, London, United Kingdom. pp. 414–499.

• Jeffrey, C., 1980. A review of the Cucurbitaceae. Botanical Journal of the Linnean Society 81: 233–247.

• van Wyk, B.E. & Gericke, N., 2000. People’s plants: a guide to useful plants of southern Africa. Briza Publications, Pretoria, South Africa. 351 pp.

• Watt, J.M. & Breyer-Brandwijk, M.G., 1962. The medicinal and poisonous plants of southern and eastern Africa. 2nd Edition. E. and S. Livingstone, London, United Kingdom. 1457 pp.

Other references

• Keraudren, M., 1966. Cucurbitacées (Cucurbitaceae). Flore de Madagascar et des Comores (plantes vasculaires), famille 185. Muséum National d’Histoire Naturelle, Paris, France. 173 pp.

• Kirkbride Jr, J.H., 1993. Biosystematic monograph of the genus Cucumis (Cucurbitaceae): botanical identification of cucumbers and melons. Parkway Publishers, Boone, North Carolina, United States. 159 pp.

• Meeuse, A.D.J., 1962. The Cucurbitaceae of southern Africa. Bothalia 8(1): 1–112.

• Schippers, R.R., 2000. African indigenous vegetables. An overview of the cultivated species. Natural Resources Institute/ACP-EU Technical Centre for Agricultural and Rural Cooperation, Chatham, United Kingdom. 214 pp.

• Staub, J.E. & Palmer, M.J., 1987. Resistance to downy mildew [Pseudoperonospora cubensis (Berk. & Curt.) Rostow.] and scab (spot rot) [Cladosporium cucumerinum Ellis & Arthur] in Cucumis spp. Cucurbit Genetics Cooperative Report 10: 21–23.

Author(s)

• C.H. Bosch, PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands

Correct citation of this article

Bosch, C.H., 2004. Cucumis africanus L.f. [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 22 December 2024.