Prota 2: Vegetables/Légumes
Ann. Sci. Nat. Bot., sér. 4, 11: 22 (1859).
2n = 24
Cucumis leptodermis Schweick. (1933).
Gooseberry cucumber, prickly paddy cucumber (En).
Origin and geographic distribution
Cucumis myriocarpus originates from Zambia, Botswana, Zimbabwe, Mozambique, South Africa and Lesotho. It has been introduced in several other regions, and has become naturalized in southern Europe, California and Australia. Locally it is considered a weed; in California it has been declared noxious.
Leaves of Cucumis myriocarpus are collected in the wild for use as a cooked vegetable. The fruit pulp is widely used as an emetic and purgative. Overdosing and/or inclusion of seeds in the pulp have been blamed for fatal cases of poisoning. Cucumis myriocarpus is suspected of causing photosensitization in sheep and blindness in cattle. However, reports on medicinal use and toxicity of Cucumis myriocarpus are suspected of wrong identification, and may refer to other species.
The nutritive value of the leaves is unknown, but probably it is comparable to Cucumis africanus L.f. leaves and other dark green leaf vegetables. Fresh fruits of Cucumis myriocarpus contain cucurbitacins A and D. Cucurbitacins, which are known from many Cucurbitaceae and various other plant species, exhibit cytotoxicity (including antitumour activity), anti-inflammatory and analgesic activities.
Annual, monoecious, prostrate or scandent herb, with simple tendrils; stems up to 2 m long. Leaves simple, alternate; petiole 1.5–10 cm long; blade broadly ovate, very deeply palmately 5-lobed, 2.5–10 cm × 2–7.5 cm, shallowly cordate at base, lobes elliptical, each again rather deeply 3–5-lobed. Flowers unisexual, regular, 5-merous; receptacle 2–5 mm long; sepals 1–3 mm long; petals 3–6(–10) mm long, pale yellow; male flowers 1–2 (rarely more) together, pedicel 0.5–2.5 cm long, stamens 3; female flowers solitary, together with male, pedicel 1.5–4.5 cm long, ovary shortly and softly spiny. Fruit a globose to ellipsoid berry 3–6(–9) cm × 1.5–2.5 cm, with spines up to 2 mm long; fruit stalk 4.5–7 cm long, slender. Seeds ellipsoid, 5–6 mm × 2.5–3 mm × 1–1.5 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 myriocarpus is placed in the ‘anguria’ group of the subgenus Melo. Two subspecies are distinguished based on fruit characteristics: subsp. leptodermis (Schweick.) C.Jeffrey & P.Halliday is confined to South Africa, subsp. myriocarpus has a much wider distribution and differs from the former by its fruits having a more distinct pattern of stripes (dark green, pale green, white, purplish, brown and rusty orange) and being densely covered with spines.
Cucumis myriocarpus is found in open localities in grassland and wooded grassland, especially on sandy soils at altitudes of 350–2000 m. It is frequently found as a weed of cultivated land and irrigation furrows.
In southern Africa Cucumis myriocarpus is an important weed in maize fields. Poisoning of cattle grazing the stubble of weedy fields is a serious risk. As a weed it can easily be controlled mechanically.
Genetic resources and breeding
As Cucumis myriocarpus is widespread and common, it is not threatened by genetic erosion. There are genebank accessions recorded in Germany, the Czech Republic, Spain, the United Kingdom and the United States.
Within the ‘anguria’ group of about 16 spiny-fruited Cucumis species to which Cucumis anguria belongs as well, there are no major barriers to gene exchange. Several interspecific crosses have been made in this group. Individual plants of Cucumis myriocarpus have been found with intermediate resistance to downy mildew (Pseudoperonospora cubensis) and resistance to scab (Cladosporium cucumerinum).
As a vegetable Cucumis myriocarpus will remain only locally of some importance and its spread is to be discouraged. It is promising as a source of disease and pest resistance for economically important Cucumis species.
• Jeffrey, C., 1975. Further notes on Cucurbitaceae 3. Some southern african taxa. Kew Bulletin 30(3): 475–493.
• Jeffrey, C., 1978. Cucurbitaceae. In: Launert, E. (Editor). Flora Zambesiaca. Volume 4. Flora Zambesiaca Managing Committee, London, United Kingdom. pp. 414–499.
• 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.
• 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.
• 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.
Correct citation of this article:
Bosch, C.H., 2004. Cucumis myriocarpus Naudin In: Grubben, G.J.H. & Denton, O.A. (Editors). PROTA 2: Vegetables/Légumes. [CD-Rom]. PROTA, Wageningen, Netherlands.