The bright red, juicy fruits of this climber will attract birds to your garden.
Variable dioecious perennial. Tuber ellipsoid-ovoid, up to 0.6 x 0.25 m, buried up to 60 cm below ground level and sending up gnarled, fibrous stems, 10-30 mm in diameter. Stems herbaceous, annual, ± 5-angled and 5-furrowed, prostrate or climbing, ± hairy, up to 1.5 m long. Leaves up to 60 mm long and broad, shallowly to very deeply 5-lobed, dark green, glabrous to shortly hairy and rough on both sides; leaf stalk up to 25 mm long. Bract at base of leaf stalk usually absent. Tendrils simple. Male flowers solitary or in groups; flower stalks up to 50 mm long; receptacle tubular, 18-22 mm long; sepals minute; petals linear, 18-24 mm long, spreading, greenish yellow (citrine), often tinged with red/brown. Female flowers solitary; flower stalks up to 25 mm long; ovary 6-8 mm long, separated by a constriction from the 10-15 mm long receptacle; sepals and petals as in male flowers. Fruit ellipsoid-oblong, 30-40 x 20-30 mm, glossy, bright orange or red. Seed ovoid, 8-10 mm long, white, usually smooth, hard, enclosed in white jelly, ± 10 per fruit.
Trochomeria macrocarpa subsp. macrocarpa occurs throughout northern and eastern tropical Africa from Senegal to the Sudan and Ethiopia, down to southern Africa where it is found in Botswana and Swaziland and also in the Limpopo, North-West, Gauteng, Mpumalanga and KwaZulu-Natal provinces of South Africa. The typical subsp. macrocarpa has ellipsoid-oblong fruit and usually no bract at the base of the leaf stalk. The subsp. vitifolia (Hook.f.) R.Fern. & A.Fern. is restricted to Angola and Namibia, has ellipsoid fruit and a 15 x 15 mm, half-circular bract at the base of the leaf stalk.
This species grows in well-drained or moist, sandy, loamy and/or rocky soils, among rocks on granite/quartzite outcrops and wooded ridges, also on flat areas, along river banks and even rarely in disturbed ground. It has been recorded from gentle to moderate northern and northeastern slopes, sheltered spots underneath rocks, under trees and in wooded gorges in deep shade. It is associated with sweet and sour bushveld (with thorn trees, Combretum, Spirostachys among others), savanna and grassland vegetation.
Derivation of the name
The genus name Trochomeria is derived from two Greek words, namely trochos (a wheel) and meris (a part). The connection to the plant is rather obscure; perhaps the long, narrow corolla lobes look like the spokes of a wheel? Trochomeria is an African genus of about eight species; four species occur in all regions of southern Africa, except Lesotho, the Free State and the Western Cape.
The species name macrocarpa, from the Greek makros (long) and karpos (fruit) simply refers to the fairly large fruit. The four species in our area are distinguished mainly according to leaf and stem characters, flower size and the absence or presence of bracts at the base of the leaf stalks.
The family 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.
Trochomeria macrocarpa grows from about 610-1 525 m above sea level in areas with an annual summer rainfall of about 600 mm to over 1 000 mm. Based on the information on specimen labels in the National Herbarium (PRE), the flowering time is from August to February, mainly in October after the first summer rains. The flowers are frequently precocious, that means that they appear before the leaves. The fruiting time is from September to March, mainly from October to January. Birds eat the bright red, fleshy, ripe fruit.
Uses, cultural aspects and toxicity
A specimen collected in Swaziland by D.R. Keith and sent to PRE for identification in July 1952, carries the following notes: 1, 'Natives say if they eat the fruit, it keeps them going all day without other food'; 2, ' Twala ben joni (sic), Swazi name for a plant with large tuber which some native doctors use pulped for wounds and sores'. Both these statements need scientific investigation!
Watt & Breyer-Brandwijk (1962) state in their monumental work on medicinal and poisonous plants that the ripe fruit of Trochomeria macrocarpa may be confused with the highly toxic fruit of Adenia digitata in the Passifloraceae (bobbejaangif). This species is also a creeper with tendrils and deeply lobed leaves, but it has two prominent glands at the leaf base and differently shaped flowers. T. macrocarpa is not known to be toxic in any part.
Growing Trochomeria macrocarpa
This species is not discussed in any of the standard horticultural books on indigenous South African plants. However, its natural habitat and ecology can be used as guidelines. It can be grown from seed and should do well in an area with little or no frost and a good rainfall. It will need the shade and support of a tree or shrub, and also well-drained to moist, sandy or loamy soil.
References and further reading
- Jackson, W.P.U. 1990. Origins and meanings of names of South African plant genera. Ecolab, Botany Department, University of Cape Town.
- Jeffrey, C. 1967. Cucurbitaceae. Flora of tropical East Africa: 85-90.
- Jeffrey, C. 1978. Cucurbitaceae. Flora zambesiaca 4: 456-460.
- Meeuse, A.D.J. 1954. The Flowering Plants of Africa 30: t. 1168.
- Meeuse, A.D.J. 1962. The Cucurbitaceae of southern Africa. Bothalia 8: 85-91.
- Watt, J.M. & Breyer-Brandwijk, M.G. 1962. Medicinal and poisonous plants of southern and eastern Africa, edn 2. Livingstone, Edinburgh & London.