AgroForestryTree Database
Olea europaea ssp. africana
 Species identityEcology and distributionPropagation and managementFunctional usesPests and diseasesAdditional InfoBibliographyImages |
Species identity
TaxonomySynonym(s)
Common names
(Afrikaans) : olienhout, olyfboom, swartolienhout
(Amharic) : weira
(Arabic) : zeitun bari
(English) : African wild olive, brown olive, Olive, wild olive
(German) : Ölbaum
(Ndebele) : umnquma
(Shona) : mupfungo
(Somali) : wera
(Tigrigna) : awliie
(Trade name) : brown olive
(Zulu) : umNqumo
Botanic description
Olea europaea ssp. africana is a shrub or a small to medium sized tree 5-10 m in height, occasionally reaching 18 m. Bark is grey to brownish-blackish, smooth to rough when old. Leaves narrowly oblong-elliptic, 2-10 cm x 7-17 mm, grey-green to shiny dark green above, greyish or yellowish with a dense covering of silvery, golden or brown scales on the under surface; apex and base narrowly tapering, apex sharp tipped; margin entire, rolled under and curved back from the midrib, petiole slender, up to 10 mm long, so the leaves tend to droop. Flowers greenish-white or cream, 6-10 mm long, sweetly scented, in loose axillary or occasionally terminal heads, 5-6 cm long. Fruit ovoid, thinly fleshy, about 10 x 8 mm tapering to a sharp tip, dark brown or black when mature. Ssp. africana (Mill.) P.S. Green is the only subspecies that occurs south of the Zambezi River.
Ecology and distribution
History of cultivationOlive trees have been cultivated for oil extraction and for edible fruit for at least 5 000 years. The deliberate propagation of O. europaea cultivars has long been practised in Mediterranean countries as well as southern Africa, Australia and the New World where olive trees were introduced by Italian and Spanish travellers.
Natural Habitat
O. europea ssp africana is widely distributed in its native range of southern Africa occurring in a variety of habitats, usually near water, on stream banks, in riverine fringes, but also in open woodland, among rocks and in mountain ravines. It is resistant to both frost and drought. Dry upland evergreen forest (edges, remnants) often associated with Juniperus; may be co dominant; also in woodland on lava flows.
Geographic distribution
Native : China, Eritrea, Ethiopia, France, India, Italy, Kenya, Mozambique, South Africa, Spain, Swaziland, Tanzania, Uganda, Zimbabwe
Biophysical limitsAltitude: 0-1 500 m Soil type: Acid soils are not a problem for it.
Reproductive Biology
In it native range the fruits typically ripen in September, towards the end of the rainy season. Usually only 1 ovule is fertilized.
Propagation and management
Propagation methodsLocal attempts in Eritrea to reforest this species have been unsuccessful due to seed germination ranging from 0-5%. A large increase in germination is obtained by removing the endocarp; it imposes a mechanical constraint to germination not a chemical one. Cracking with a hand vice or by rolling a stone over seeds can cause the endocarp to break along or across the suture line, which bisects it. By removing the endocarp germination is greatly enhanced, reaching up to 92% in seed stored for 18 months. Low temperature stratification does not appear to be necessary. Seedlings should not be outplanted shortly after being fertilized. Cuttings root fairly easily. Rooting and the growth of new leaves are strongly influenced by the nutrient status of parent plants and the application of rooting hormone to the base of cuttings.Tree Management
Unfertilized seedlings show drought tolerance whilst fertilized seedlings do not. Fertilization with adequate watering results in greatly increased shoot growth but little change in root growth. In summary, plants need adequate nutrition and water to grow, and irrigation or fertilizing plants usually increases their growth where water or nutrients are deficient. Fertilization and irrigation need to be carefully managed to ensure optimal growth is consistent with post-transplant survival.
Germplasm Management
Seed storage behaviour is orthodox. Viability can be maintained for several years in hermetic storage at 3 deg. C with 6-10% mc. The seeds can be stored at dry room temperature for a few years. There are approximately 13 800 seeds/kg.
Functional uses
ProductsFood: The main olive products are olive oil and edible olives. The fleshy, oil-bearing mesocarp used in commercial olive growing is absent in the much smaller fruits of O. europaea ssp. africana. Fodder: The plants are much browsed on by livestock. Fuel: In Eritrea the villagers use wild olive extensively to provide fuelwood. Timber: Wood is hard and heavy, weighing approximately 1 140 kg/cubic m. Sapwood is light brown while the heartwood is red-brown to yellow, with dark figuring. The wood is fine-textured and finishes well, and is often used to make ornaments such as wall clocks and vases. Jewellery items such as beads, brooches and bangles are also made from wild olive wood. Although the tree does not produce sawable logs or branches, there are still several furniture-makers that, with great effort produce furniture from the limited quantities of timber. Medicine: The Wandorobo and Kipsigis of Kenya use a root or bark decoction as a remedy for malaria.Services
Reclamation: The high drought tolerance of O. europaea ssp. africana suggests that it is a good candidate for reforestation in semi-arid zones of Africa such as Rora Habab, Eritrea. Ornamental: Olive plantations have the capacity to beautify the landscape.
Bibliography
Albrecht J. ed. 1993. Tree seed hand book of Kenya. GTZ Forestry Seed Center Muguga, Nairobi, Kenya.Beentje HJ. 1994. Kenya trees, shrubs and lianas. National Museums of Kenya.
Bein E. 1996. Useful trees and shrubs in Eritrea. Regional Soil Conservation Unit (RSCU), Nairobi, Kenya.
Bekele-Tesemma A, Birnie A, Tengnas B. 1993. Useful trees and shrubs for Ethiopia. Regional Soil Conservation Unit (RSCU), Swedish International Development Authority (SIDA).
Coates-Palgrave K. 1988. Trees of southern Africa. C.S. Struik Publishers Cape Town.
Drummond BR. 1981. Common trees of the Central Watershed Woodlands of Zimbabwe. National Resources Board.
Dyer C, Esterhuyse CJ. 1988. Tree of the year, (1988): Olea capensis. Department of Environmental Affairs.
Hong TD, Linington S, Ellis RH. 1996. Seed storage behaviour: a compendium. Handbooks for Genebanks: No. 4. IPGRI.
ICRAF. 1992. A selection of useful trees and shrubs for Kenya: Notes on their identification, propagation and management for use by farming and pastoral communities. ICRAF.
Katende AB et al. 1995. Useful trees and shrubs for Uganda. Identification, Propagation and Management for Agricultural and Pastoral Communities. Regional Soil Conservation Unit (RSCU), Swedish International Development Authority (SIDA).
Leeuwenberg AJM. 1987. Medicinal and poisonous plants of the tropics. Pudoc Wageningen.
Legesse N. 1993. Investigations on the germination behaviour of wild olive seeds and the nursery establishment of the germinants. Sinet, an Ethiopian Journal of Science. 16(2):71-81.
Mbuya LP et al. 1994. Useful trees and shrubs for Tanzania: Identification, Propagation and Management for Agricultural and Pastoral Communities. Regional Soil Conservation Unit (RSCU), Swedish International Development Authority (SIDA).
Nicholson B.E, Harrison S.G, Masefield G.B & Wallis M. 1969. The Oxford Book of Food Plants. Oxford University Press.
Noad T, Birnie A. 1989. Trees of Kenya. General Printers, Nairobi.
Scott Jones P. 1991. Restoration of Juniperus excelsa and Olea europaea subsp. africana woodlands in Eritrea. A thesis presented for the degree of Doctor of Philosophy at the University of Stirling.
Tietema T, Merkesdal E and Schroten J. 1992. Seed germination of indigenous trees in Botswana. Acts Press.
Venter F, Venter J-A. 1996. Making the most of Indigenous trees. Briza Publications.