Acanthosicyos naudinianus (PROTA)

Plant Resources of Tropical Africa Introduction

List of species

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

Acanthosicyos naudinianus (Sond.) Jeffr.

Protologue: Kew Bull. 15(3): 346 (1962).

Family: Cucurbitaceae

Chromosome number: n = 11

Synonyms

Cucumis naudinianus Sond. (1862), Citrullus naudinianus (Sond.) Hook.f. (1871), Colocynthis naudianus (Sond.) Kuntze (1891).

Vernacular names

Herero cucumber, gemsbok cucumber, wild melon (En).

Origin and geographic distribution

Acanthosicyos naudinianus is native to Zambia, Angola, Namibia, Botswana, Zimbabwe, Mozambique and South Africa.

Uses

The mature fruits of Acanthosicyos naudinianus are eaten raw or roasted; unripe fruits cause a burning sensation of the tongue and lips when eaten raw. The fruit also provides an important source of water. The fruit skin and the seeds are roasted and pounded to make a meal. The tuberous roots are considered inedible or even poisonous and in Zambia they have been reportedly used for homicidal purposes. The preparation and use of arrow poison made from the roots of Acanthosicyos naudinianus is widespread among bushmen tribes in Angola, Namibia and Botswana.

Properties

Some Acanthosicyos naudinianus plants produce bitter fruits. The bitter taste is attributed to cucurbitacin B (c. 0.001%). Fruits contain per 100 g:: water 90.6 g, energy 111 kJ (27 kcal), protein 1.3 g, fat 0.2 g, carbohydrate 4.8 g, fibre 2.1 g, Ca 21 mg, Mg 23 mg, P 25 mg, Fe 0.5 mg, thiamin 0.09 mg, riboflavin 0.03 mg, niacin 0.98 mg and ascorbic acid 35 mg (Arnold, T.H., Wells, M.J. & Wehmeyer, A.S., 1985). The seed kernel yields c. 15% thin, yellow non-drying oil, and the residue contains c. 20% protein. In the older roots the total content of cucurbitacins amounts to 1.4%. Cucurbitacins, which are also known from other Cucurbitaceae and various other plant species, exhibit cytotoxicity (including antitumour activity) and anti-inflammatory and analgesic activities.

Description

Perennial, dioecious, scandent herb with solitary, spiniform tendrils; root tuberous, up to 1 m long; stem annual, up to 6 m long, rooting at the nodes, glabrescent. Leaves alternate, simple; stipules absent; petiole 0.7–7.5 cm long; blade ovate to broadly ovate in outline, usually deeply palmately 5-lobed, 3–18 cm × 2.5–14 cm. Flowers solitary, unisexual, 5-merous; petals yellow to white, 1.4–2.5 cm × 0.9–1.3 cm; male flowers with pedicel up to 2 cm long, receptacle campanulate, up to 6 mm long, pale green, sepals up to 6 mm × 1.5 mm, stamens 3 or 5; female flowers with pedicel up to 8 cm long, receptacle cylindrical, 3 mm long, sepals 3–4 mm long, 3 small staminodes, ovary inferior, spiny. Fruit an ellipsoid or subglobose berry 6–12 cm × 4–8 cm, weight c. 250 g, fleshy, covered with seta-tipped fleshy spines, many-seeded. Seeds ellipsoid, slightly compressed, 7.5–10 mm × 4–6 mm.

Acanthosicyos comprises 2 species and is placed in the tribe Benincaseae together with important genera such as Benincasa, Coccinia, Citrullus, Lagenaria and Praecitrullus. The better known nara melon (Acanthosicyos horridus) differs notably from Acanthosicyos naudinianus by its shrubby habit and leafless, spiny stems, and is restricted to Angola, Namibia and South Africa.

Elephants feed on the fruits and may play an important role in the dispersal of seeds.

Ecology

Acanthosicyos naudinianus is a typical Kalahari species which prefers deep sandy soils. It occurs in woodland, wooded grassland and grassland at altitudes of 900–1350 m. It is not frost tolerant but tolerates a saline subsoil.

Management

The fruits of Acanthosicyos naudinianus are exclusively collected from the wild.

Genetic resources

There is no indication that Acanthosicyos naudinianus is threatened. As in many other cucurbits there is considerable variation in the bitterness of the fruits. This will allow for selection and breeding of more palatable lines. There are 4 documented accessions held in the United States and 2 at the Royal Botanic Gardens Kew (United Kingdom).

Prospects

In view of increasing demands for edible oil and protein in arid lands, Acanthosicyos naudinianus is a candidate for development as a high-yielding, dry country crop. It yields a crop quickly, harvesting the fruits is easy, it has a wide ecological adaptation, it is easily propagated and handled, and fruits store well. As such, it compares favourably with Acanthosicyos horridus as a candidate for domestication.

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.

• Neuwinger, H.D., 1996. African ethnobotany: poisons and drugs. Chapman & Hall, London, United Kingdom. 941 pp.

• SEPASAL, 2003. Acanthosicyos naudinianus. [Internet] Survey of Economic Plants for Arid and Semi-Arid Lands (SEPASAL) database. Royal Botanic Gardens, Kew, Richmond, United Kingdom. http://www.rbgkew.org.uk/ ceb/sepasal/acantho.htm. 24 February 2003.

Other references

• Dudley, J.P., 2000. Seed dispersal by elephants in semiarid woodland habitats of Hwange National Park, Zimbabwe. Biotropica 32(3): 556–561.

• Jeffrey, C., 1962. Notes on Cucurbitaceae, including a proposed new classification of the family. Kew Bulletin 15(3): 337–371.

• Jeffrey, C., 1979. The economic potential of some Cucurbitaceae and Compositae of tropical Africa. In: Kunkel, G. (Editor). Taxonomic aspects of African economic botany. Proceedings of the 9th plenary meeting of AETFAT. Las Palmas, Gran Canaria, Spain. pp. 35–38.

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

• Schrire, B.D., 1987. Cucurbitaceae, orthographic ambiguity clarified. Bothalia 17(2): 181.

• 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.

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. Acanthosicyos naudinianus (Sond.) C.Jeffrey. [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. <http://www.prota4u.org/search.asp>.

Accessed 12 December 2024.

• See the Prota4U database.