Lagenaria sphaerica (Sond.) Naudin
Common names: wild calabash (Eng.); wildekalbas (Afr.); iselwa-makhosi, uselwa (Zulu)
This vigorous climber is a close relative of the calabash and bears large, white, fragrant flowers which open in the evening, and unique mottled green fruit the size of a cricket ball. Try growing something different around your patio this summer!
Perennial with a woody rootstock. Stems annual, herbaceous, robust, climbing or trailing, angular, hairless, up to 10 m long or longer, often completely leafless when fruiting. Leaves rather rigid, shaped like a hand, margins toothed, 50-180 mm long, both surfaces roughly and shortly hairy, upper surface dark green, lower surface paler; foetid when crushed. Leaf stalks 20-80 mm long, with two lateral apical yellow-green glands. Tendrils split in two.
Flowers fragrant, opening in the evenings, corollas saucer-shaped, velvety white or cream-coloured with green veins, petals rounded, 22-60 mm long; male and female flowers on separate plants (dioecious). Male flowers 2-10 in racemes, anthers prominent, yellow, greatly contorted. Female flowers solitary, stalked. Fruit hanging from a stout 30-100 mm long stalk, subspherical, 60-100 mm across, deep green with pale green or yellowish transverse, slightly raised patches, with a hard shell and whitish flesh, foul smelling when ripe. Seeds whitish to yellowish, oblong-triangular in outline, flattened, 10-15 mm long.
Distribution and habitat
L. sphaerica is found naturally in tropical and southern Africa from Somalia down to the Western Cape; it also grows on Madagascar and the Comores. In southern Africa it has been recorded from Botswana and the following provinces in South Africa: Limpopo, Mpumalanga, KwaZulu-Natal, Eastern Cape and Western Cape to about Knysna. It should also occur in Swaziland, but apparently has not yet been collected there.
The wild calabash grows in full sun and semi-shade in forest margins, evergreen and deciduous forests, in riverine woodland, on river banks and in dry river beds, also in dry scrub thickets and ground-water forests (Jeffrey 1967). It is also recorded from swamp forests, littoral dunes and maritime scrub on the seashore. It is usually found in well-drained loam, sandy loam and stony, sandy soil.
Derivation of name and historical aspects
The genus name Lagenaria comes from lagena, the Latin name for a Florence flask; referring to the fruit of the calabash (L. siceraria). The species name sphaerica comes from the Greek word for a sphere, referring to the fruit of this particular species. This plant was previously known as L. mascarena Naudin and Luffa sphaerica Sond.
The Cucurbitaceae consists of about 120 genera and 735 species that are cosmopolitan in mostly tropical and subtropical countries. Many species are cultivated and of economic importance as food plants such as cucumber, melon, pumpkin and watermelon. Members of this family are annual or perennial herbs or shrubs (only one species is a tree). The leaves are alternate and variable and tendrils are almost always present. The flowers are mostly unisexual and white or yellow; they occur on the same plant (monoecious) or on separate plants (dioecious). The fruit often is an indehiscent berry (soft-shelled) or gourd (hard-shelled) with one to many, often flattened seeds. There are about 18 genera and 75 species of this family in southern Africa.
The genus Lagenaria contains six species, probably all Old World and mainly African. L. siceraria, the calabash, is now pantropical. Only two species are found in southern Africa; L. siceraria and L. sphaerica.
The wild calabash flowers in all months, but mainly from December to May. Fruiting specimens have been collected almost throughout the year. In southern Africa it grows from about sea level to 915 m, in dry and wet areas with a rainfall of 200-1 200 mm annually. The flowers are visited by bees, ants and flies and presumably also by moths, as the flowers open in the evenings.
According to Watt & Breyer-Brandwijk (1962), the fruit is bitter because of elaterase activity. Hutchings et al. (1996) report that in Zulu medicinal usage, infusions made from two handfuls of a mixture of leaves or roots with those of Bidens pilosa (blackjack), in a large cupful of hot water, are taken for stomach ache or administered as enemas. Pounded root decoctions are used for treating swellings thought to be caused by blood disorders. The fruit is also used as traditional medicine, sometimes in succession ceremonies after the death of a chief. The fruit is reported to be an ingredient in a Xhosa remedy for glandular swellings. Walker (1996) notes that the fruit is sold on Indian markets 'as they are used for Hindu prayers'.
Growing Lagenaria sphaerica
This species is not discussed in any of the standard horticultural works on indigenous South African plants. However, looking at its habitat and ecology, one can make some deductions. The wild calabash can be grown from seed in frost-free areas, preferably with a good rainfall. It can also be grown in dry areas with a fairly high ground-water level. Of course it needs trees, shrubs or other support to climb into or lean on.
- Hutchings, A., Scott, A.H., Lewis, G. & Cunningham, A.B. 1996. Zulu medicinal plants, an inventory. University of Natal Press, Pietermaritzburg.
- Jackson, B.D. 1960. A glossary of botanic terms. Duckworth, London.
- Jeffrey, C. 1967. Cucurbitaceae. Flora of tropical East Africa : 47-53.
- Jeffrey, C. 1978. Cucurbitaceae. Flora zambesiaca 4: 437-440.
- Meeuse, A.D.J. 1962. The Cucurbitaceae of southern Africa. Bothalia 8: 82-85.
- Pooley, E. 1998. A field guide to wild flowers, KwaZulu - Natal and the eastern region. Natal Flora Publications Trust.
- Walker, J. 1996. Wild flowers of KwaZulu - Natal. W.R. Walker family Trust, Pinetown
- Watt, J.M. & Breyer-Brandwijk, M.G. 1962. Medicinal and poisonous plants of southern and eastern Africa, edn 2. Livingstone, Edinburgh & London.
National Herbarium, Pretoria
Plant Type: Perennial, Scrambler
SA Distribution: Eastern Cape, KwaZulu-Natal, Limpopo, Western Cape
Soil type: Sandy, Loam
Flowering season: Spring, Early Summer, Late Summer
Flower colour: White
Aspect: Full Sun
Gardening skill: Average