This member of the grape family is an attractive hardy creeper with shiny three- or five-partite leaves. It is traditionally used to make jam and also rope.
Rhoicissus digitata is a mainly woody perennial climber with a possible spread of 10–15 m, but it can also be a large loose, somewhat untidy shrub to about 1.5 m high. The main stem is woody with distinctively russet-orange hairs covering young stems. New leaves can be conspicuously rust-red. Tendrils occur opposite the leaves which are digitally compound, with three to five leaflets with very short stalks. The middle leaflet is always a bit longer than the others. The leaves are shiny dark green above and with fine russet hairs below, the margin is entire and rolled under. Small greenish-yellow inconspicuous flowers are borne in clustered, drooping, branched heads in the leaf axils in late summer (January to April). Red-brown to purple fleshy berries, approx. 15 mm in diameter, resembling “grapes” but tasting rather tart, ripen from autumn to winter (March to August).
The current conservation status of this plant is ‘Least Concern'.
Distribution and habitat
It grows freely in grassland, bush, on forest margins and on coastal dunes and dry sand forest in the Western Cape, Eastern Cape, KwaZulu-Natal, Mpumalanga, Swaziland and Mozambique at altitudes from 0–600 m.
Derivation of name and historical aspects
From Latin rhoicus, meaning ‘of Rhus' and cissus, meaning ‘ivy', or perhaps fromGreek rhoia, a pomegranate, and ‘digitata' meaning ‘fingered', referring to the appearance of the leaf, as all the leaflets arise from one base, as fingers do from a palm.
The grape family (Vitaceae) is large, with approximately 14 genera and a 1000 species, including the grape vine, Vitis vinifera. Members of this family occur in the tropical to temperate regions of the world and are mainly erect, prostrate or climbing herbs often with swollen or jointed nodes, and also erect or semiscandent shrubs or trees with thick succulent stems.
Rhoicissus is a small genus of evergreen climbers native to tropical and southern Africa. In South Africa the whole Vitaceae family is represented by five genera and 53 species, and the genus Rhoicissus is represented by 10 species which occur in all the provinces except for the Northern Cape.
Other worthwhile species are the two canopy climbers, Rhoicissus tomentosa and R. rhomboidea. A means of distinguishing them is that R. tomentosa has simple or shallowly lobed leaves and R. rhomboidea has 3-foliolate leaves with toothed margins.
R. digitata and R. revoilii are two species with entire margins that are difficult to tell apart except that R. digitata sometimes has 5-foliolate leaves, although most are 3-foliolate, the leaflet apex is rounded and the leaflet stalks are very short. In R. revoilii the leaves are always 3-foliolate with the leaflet apex often tapering to a point, and each leaflet has a stalk up to 20 mm long. Also in R. digitata tendrils are frequently present but are seldom seen on R. revoilii.
The flowers have nectar that attracts bees and wasps. The fruits are eaten by birds and mammals. Larvae of various moths feed on Rhoicissus and the leaves are also browsed by game. Large tuber-like roots are eaten by bushpigs.
This tough climber is often the pioneer species on dunes, colonizing the windward slopes of the front dunes by forming a twining maze of stems.
Uses and cultural aspects
Uses of Rhoicissus digitata are mainly in ornamental horticulture as a tough, hardy climber. It is also used as an ophthalmic remedy in Zimbabwe/Zambia [Rhodesia]. The fruit has been used in making jam, and the vine is used by the Xhosa as a rope for tying down thatch and in basket making.
Other members of the genus have many medicinal, culinary and traditional uses. The fruit of R. rhomboidea is edible. The Lobedu use the fleshy root of R. erythrodes (now R. tridentata subsp. cuneifolia ) in the treatment of the condition known to them as popo ya muyana, where the objective is to strengthen the part of the head of babies which is soft and pulsating. The swollen root is cut into quarters and boiled in water; this is used to make a soft mealie pap which is fed to the infant and then also portions of the plant are stamped into a pulp and applied over the fontanelle. This plant is also used as an epilepsy remedy and the purple fruit is edible. The Masai take a decoction of the root as a nerve stimulant and gonorrhoea remedy and the plant juice is used as a dressing for spear wounds. Poisoning of swine from eating the root of Rhoicissus erythrodes has been reported from Tanganyika. The stem of Rhoicissus revoilii contains a great deal of thin acid juice which is valued in Tanganyka in times of water shortage, and is also used as an addition to palm wine.
Growing Rhoicissus digitata
A relatively fast growing and vigorous climber that requires sun with some shade and compost-enriched soil to thrive. It grows well on fences as a screen and it can also be trained around a pillar for shading on a pergola, or allowed to make its way up into a tree or spread across the ground as an attractive groundcover in full sun and in semi-shade. It can even be allowed to form a small loosely stemmed shrub. Once established it will tolerate moderate frost and drought. It is particularly useful in a coastal garden and can be especially effective in stabilizing open sandy areas and dunes.
It is not very showy, although the new red leaves are quite attractive. Its garden appeal lies in its toughness and ability to quickly cover a fence and form an effective screen, or provide evergreen shade.
In the small garden, cut it back somewhat each year to limit its spread, or plant it in a container which will restrict its growth.
It is easily propagated from seed sown in spring or early summer and takes from three to six weeks to germinate. Soaking in hand-hot water overnight and treating with a fungicide that combats pre- and post-emergence damping off, although not essential for germination, will increase the number of successful seedlings. Sow cleaned seed in a seed tray in a well-drained, well-aerated soil mix. Spread the seeds evenly and cover with a layer of sand. Water the seed tray and place it in a warm place until germination takes place in three to five weeks under optimum conditions. Prick out soon after the first pair of true leaves has developed – taking care not to damage the young root.
Also easy to propagate from semihardwood cuttings made in spring and summer when plants are actively growing. Use a well-draining medium such as a 1:1 mixture of fine bark and river sand, 1:1 fine bark and polystyrene or plain coarse river sand. Cuttings do best placed under mist with bottom heat, and rooting is improved if hormones are used. Rooting will occur within three to four weeks.
Propagation by layering runners/suckers from the plant is also successful.
References and further reading
- Coombes, A.J. 1992. Guide to plant names. Reed International Books, Finland.
- Germishuizen, G. & Meyer, N.L. (eds) Plants of southern Africa: an annotated checklist. Strelitzia 14. National Botanical Institute, Pretoria.
- Gibson, J.M. 1975. Wild flowers of Natal (Coastal Region ). Trustees of the Natal Publishing Trust Fund, Durban.
- Joffe, P. 2001. Creative gardening with indigenous plants, edn 1. Castle Graphics, Johannesburg.
- Johnson, D. and S. & Nichols, G. 2002. Gardening with indigenous shrubs. Struik, Cape Town.
- Leistner, O.A. (ed.). 2000. Seed plants of southern Africa: families and genera. Strelitzia 10. National Botanical Institute, Pretoria.
- Pienaar, K.1991. Gardening with indigenous plants. Struik Timmins Publishers, Cape Town.
- Pooley, E. 1993. The complete field guide to trees of Natal, Zululand and Transkei. Natal Flora Publications Trust, Durban.
- Powrie, F. 1998. Grow South African plants. National Botanical Institute, Kirstenbosch, Cape Town.
- Sheat, W.G. 1982. The A–Z of gardening in South Africa. Struik, Cape Town.
- Trinder-Smith, T.H. 2003. The Levyns guide to the plant genera of the southwestern Cape. Bolus Herbarium, University of Cape Town, Cape Town.
- Van Wyk, B.-E. & Gericke, N. 2000. People's plants: a guide to useful plants of southern Africa. Briza Publications, Pretoria.
- Watt, J.M. & Breyer-Brandwijk & M.G. 1962. Medicinal and poisonous plants of southern and eastern Africa,edn 2.Livingstone, Edinburgh and London.
Kirstenbosch National Botanical Garden