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Lannea welwitschii (Hiern) Engl.

Protologue
Bot. Jahrb. Syst. 24: 298 (1898).
Family
Anacardiaceae
Chromosome number
2n = 28
Vernacular names
Muumbu (Sw).
Origin and geographic distribution
Lannea welwitschii occurs from Liberia east to western Ethiopia and Kenya, and south to Tanzania and northern Angola; possibly also in northern Mozambique.
Uses
The wood, often known as ‘kumbi’ is used for light joinery, boxes, crates, utensils such as cups, plates, pots and mortars, and for veneer and plywood. The boles are traditionally used to make canoes. The wood is suitable for light flooring, interior trim, vehicle bodies, furniture, cabinet work, matches, hardboard, particle board and pulpwood. It is also used as firewood and for charcoal production.
The bark yields an orange-yellow to reddish brown dye that is used in Ghana for dyeing traditional mourning cloth. It is also used for rope and for making sandals. The bark is commonly used in traditional medicine. Decoctions are administered to treat diarrhoea, haemorrhoids, sterility in women, menstrual troubles, pain after childbirth, gonorrhoea, epilepsy, oedema, palpitation, skin infections and ulcers. Powdered bark is applied to snakebites and wounds. In Ghana the bark is used in mixtures with parts of other plants to treat diabetes. Root decoctions are considered as expectorant and emetic and taken to treat pulmonary and mouth infections, and as antidote in cases of poisoning. Pounded leaves are applied as a dressing to treat oedema and are taken in palm wine against epilepsy. The seeds are used as a purgative. The fruits are locally eaten fresh, although they are resinous and the taste is acidic with a smell of turpentine. The tree is occasionally planted as shade tree in coffee and cocoa plantations, in life fences, and as a roadside tree. Leaves are sometimes fed to cattle. Mulch from the leaves is considered to improve soil conditions.
Production and international trade
There are no statistics on production and trade of Lannea welwitschii wood, but apparently the amounts traded on the international market are negligible and the wood is only used locally on a smaller scale.
Properties
The heartwood is creamy white to pale brown or pinkish grey and indistinctly demarcated from the sapwood. The grain is usually straight, but occasionally interlocked, texture medium to fine and even. Quarter-sawn surfaces show a streaked or mottled figure. The wood has a silvery lustre. Resin canals with a brownish yellow content are numerous, and the wood has a resinous smell.
The wood is moderately lightweight to medium-weight, with a density of 400–640 kg/m³ at 15% moisture content. It is fairly easy to dry with little warping and checking. The rates of shrinkage are moderate. At 12% moisture content, the modulus of rupture is 76–101 N/mm², compression parallel to grain 43–45 N/mm², cleavage 11 N/mm and Chalais-Meudon side hardness 1.9.
The wood is rather difficult to saw and work, partly due to the presence of silica; it has a tendency to heat up considerably and it has a serious blunting effect on saw teeth and cutting edges. In planing operations, it often develops a woolly surface. However, with care a good finish can be obtained. The nailing properties are satisfactory, with good holding power. Gluing and polishing show acceptable results. The peeling properties are quite good. The wood is not durable. It is susceptible to blue stain, termite, pinhole borer, Lyctus and marine borer attacks. The heartwood is resistant to impregnation with preservatives, the sapwood moderately resistant. The sawdust may cause allergic reactions to skin and mucous membranes.
The presence of saponins and tannins in the bark has been demonstrated, but alkaloids seem to be absent. In in-vitro tests, water and ethanol extracts of the stem bark showed antibacterial activity against Staphylococcus aureus, Salmonella typhimurium and Streptococcus sp. Two alkylated hydroquinones, lanneaquinol and 2’(R)-hydroxylanneaquinol, have been isolated from extracts of Lannea welwitschii stems, twigs, leaves and fruits. These showed modest cytotoxicity against a panel of human tumour cell lines.
Adulterations and substitutes
The wood of other Lannea spp. has similar properties as that of Lannea welwitschii, but it is usually only available in small dimensions and consequently only used to make small objects such as mortars, small stools, hoe handles and bows. The bark of several other Lannea spp. is used in the same way as that of Lannea welwitschii in West Africa to dye wrappers reddish brown.
Description
Deciduous or evergreen, dioecious, medium-sized tree up to 30(–35) m tall; bole straight and cylindrical, branchless for up to 15(–26) m, up to 100(–120) cm in diameter, without buttresses; bark surface grey to greyish brown, initially nearly smooth but becoming scaly and developing roundish pits, inner bark reddish with white wavy lines, fibrous, with a clear and sticky exudate; crown consisting of large, spreading branches; twigs with numerous lenticels. Leaves arranged spirally, clustered at the ends of branchlets, imparipinnately compound with (3–)5–7(–13) leaflets; stipules absent; petiole and rachis together up to 25(–40) cm long, grooved above; petiolules up to 2 cm long but petiolule of terminal leaflet up to 5 cm; leaflets opposite, oblong-ovate or ovate-lanceolate, 10–20 cm × 5–10(–12) cm, cuneate to obtuse at base, long-acuminate at apex, papery, entire, glabrous, pinnately veined with 9–15 pairs of lateral veins. Inflorescence an axillary pyramidal panicle up to 20 cm long, yellowish hairy with stellate hairs; bracts ovate, 3–8 mm long. Flowers unisexual, regular, 4-merous; pedicel 2–4 mm long; calyx lobes 0.5–1 mm long; petals free, oblong-elliptical, 2.5–3 mm long, yellow-green; stamens 8, free; disk cup-shaped, slightly 8-lobed; ovary superior, 4-celled, styles usually 4; male flowers with rudimentary ovary, female flowers with rudimentary stamens. Fruit an ellipsoid to nearly globose, slightly compressed drupe 6–8 mm long, smooth, blackish purple when ripe; stone usually 1-seeded. Seedling with epigeal germination; hypocotyl 3.5–5 cm long, epicotyl 0.5–1 cm long; cotyledons linear-lanceolate, 1.5–2 cm long; first 2 leaves opposite, simple, ovate, 2.5–4 cm × c. 1.5 cm, toothed.
Other botanical information
Lannea comprises about 40 species, most of them restricted to Africa. Although most species can easily be distinguished botanically, in several areas different species bear similar vernacular names. Most species are shrubs or small trees and of no importance as timber, but several yield edible fruits and/or dyes, or are known as a medicinal plant.
A variety of Lannea welwitschii, var. ciliolata Engl. (synonym: Lannea amaniensis Engl. & K.Krause), has been distinguished. It is endemic to Kenya and Tanzania, where it occurs in lowland forest, and differs from var. welwitschii in its smaller leaflets, which are slightly hairy below.
Growth and development
Lannea welwitschii trees grow fast. In Côte d’Ivoire trees flower in January–February. In West Africa fruits are produced towards the end of the rainy season, and also in Gabon the fruiting peak is in the rainy season. The fruits are eaten by birds, which disperse the seeds.
Ecology
Lannea welwitschii occurs in lowland rainforest and riverine forest up to 1100(–1250) m altitude. It is often found in swampy areas in the forest. In West Africa it shows little preference for different forest zones, but in Cameroon it occurs most abundantly in semi-deciduous forest. In Ethiopia it is found in regions with a mean annual rainfall of 1500–2000 mm. It is especially common in secondary forest and is considered a pioneer species.
Propagation and planting
Natural regeneration is most abundant in medium-large gaps in the forest. Fruits can be collected from the ground. There are about 15,000 seeds per kg. The seeds are sown in seedbeds or directly into the field. Pre-treatment is not necessary, but the germination rate is quite low, about 30%. Germination may start within one week, but usually after 2–3 weeks. The fruits should be gradually dried before they are stored; they can be kept for up to 2 months in sealed containers in a cool place.
Management
In forest of Cameroon an average density of 0.5 bole with a diameter above 15 cm has been recorded par ha, with an average wood volume of 1.5 m³/ha. The trees can be managed by coppicing and pollarding.
Yield
In DR Congo it has been recorded that one bole (26 m long, 80 cm diameter) yielded 8.5 m³ of wood.
Handling after harvest
After felling, logs should be removed from the forest as soon as possible to prevent blue stain and pinhole borer attacks.
Genetic resources
Lannea welwitschii does not seem to be threatened by genetic erosion because it is widespread and locally common, particularly in secondary forest. However, var. ciliolata has a limited distribution area and could become threatened because of forest clearing.
Prospects
The potential of Lannea welwitschii in agroforestry systems should be investigated because it is a multipurpose tree of rapid growth. It may be an interesting species for timber plantations to be used for rotary peeling.
Major references
• ATIBT (Association Technique Internationale des Bois Tropicaux), 1986. Tropical timber atlas: Part 1 – Africa. ATIBT, Paris, France. 208 pp.
• Bekele-Tesemma, A., 2007. Useful trees and shrubs for Ethiopia: identification, propagation and management for 17 agroclimatic zones. Technical Manual No 6. RELMA in ICRAF Project, Nairobi, Kenya. 552 pp.
• Bolza, E. & Keating, W.G., 1972. African timbers: the properties, uses and characteristics of 700 species. Division of Building Research, CSIRO, Melbourne, Australia. 710 pp.
• Burkill, H.M., 1985. The useful plants of West Tropical Africa. 2nd Edition. Volume 1, Families A–D. Royal Botanic Gardens, Kew, Richmond, United Kingdom. 960 pp.
• Friis, I., 1992. Forests and forest trees of northeast tropical Africa: their natural habitats and distribution patterns in Ethiopia, Djibouti and Somalia. Kew Bulletin, Additional Series 15, H.M.S.O., London, United Kingdom. 396 pp.
• Katende, A.B., Birnie, A. & Tengnäs, B., 1995. Useful trees and shrubs for Uganda: identification, propagation and management for agricultural and pastoral communities. Technical Handbook 10. Regional Soil Conservation Unit, Nairobi, Kenya. 710 pp.
• Kokwaro, J.O., 1986. Anacardiaceae. In: Polhill, R.M. (Editor), 1986. Flora of Tropical East Africa. A.A. Balkema, Rotterdam, Netherlands. 59 pp.
• Lovett, J.C., Ruffo, C.K., Gereau, R.E. & Taplin, J.R.D., 2006. Field guide to the moist forest trees of Tanzania. [Internet] Centre for Ecology Law and Policy, Environment Department, University of York, York, United Kingdom. http://celp.org.uk/ projects/ tzforeco/. Accessed January 2009.
• Takahashi, A., 1978. Compilation of data on the mechanical properties of foreign woods (part 3) Africa. Shimane University, Matsue, Japan, 248 pp.
• Vivien, J. & Faure, J.J., 1985. Arbres des forêts denses d’Afrique Centrale. Agence de Coopération Culturelle et Technique, Paris, France. 565 pp.
Other references
• Adjanohoun, E.J., Ahyi, A.M.R., Aké Assi, L., Baniakina, J., Chibon, P., Cusset, G., Doulou, V., Enzanza, A., Eymé, J., Goudoté, E., Keita, A., Mbemba, C., Mollet, J., Moutsamboté, J.-M., Mpati, J. & Sita, P. (Editors), 1988. Médecine traditionnelle et pharmacopée - Contribution aux études ethnobotaniques et floristiques en République Populaire du Congo. Agence de Coopération Culturelle et Technique, Paris, France. 606 pp.
• Adomako, E.E., 1999. Leaf litter production and soil fertility improvement in a home garden in the Akuapem district of Ghana. MSc degree thesis, Department of Botany, Faculty of Science, University of Ghana, Accra, Ghana. 170 pp.
• Aké Assi, L., Abeye, J., Guinko, S., Riguet, R. & Bangavou, X., 1985. Médecine traditionnelle et pharmacopée - Contribution aux études ethnobotaniques et floristiques en République Centrafricaine. Agence de Coopération Culturelle et Technique, Paris, France. 140 pp.
• Aubréville, A., 1959. La flore forestière de la Côte d’Ivoire. Deuxième édition révisée. Tome deuxième. Publication No 15. Centre Technique Forestier Tropical, Nogent-sur-Marne, France. 341 pp.
• Burkill, H.M., 2000. The useful plants of West Tropical Africa. 2nd Edition. Volume 5, Families S–Z, Addenda. Royal Botanic Gardens, Kew, Richmond, United Kingdom. 686 pp.
• de la Mensbruge, G., 1966. La germination et les plantules des essences arborées de la forêt dense humide de la Côte d’Ivoire. Centre Technique Forestier Tropical, Nogent-sur-Marne, France. 389 pp.
• Fouarge, J. & Gérard, G., 1964. Bois du Mayumbe. Institut National pour l’Etude Agronomique du Congo (INEAC), Brussels, Belgium. 579 pp.
• Gilbert, M.G., 1989. Anacardiaceae (including Pistaciaceae). In: Hedberg, I. & Edwards, S. (Editors). Flora of Ethiopia. Volume 3. Pittosporaceae to Araliaceae. The National Herbarium, Addis Ababa University, Addis Ababa, Ethiopia and Department of Systematic Botany, Uppsala University, Uppsala, Sweden. pp. 513–532.
• Groweiss, A., Cardellina, J.H., Pannell, L.K., Uyakul, D., Kashman, Y. & Boyd, M.R., 1997. Novel cytotoxic, alkylated hydroquinones from Lannea welwitschii. Journal of Natural Products 60(2): 116–121.
• Hawthorne, W.D., 1995. Ecological profiles of Ghanaian forest trees. Tropical Forestry Papers 29. Oxford Forestry Institute, Department of Plant Sciences, University of Oxford, United Kingdom. 345 pp.
• Hawthorne, W. & Jongkind, C., 2006. Woody plants of western African forests: a guide to the forest trees, shrubs and lianes from Senegal to Ghana. Kew Publishing, Royal Botanic Gardens, Kew, United Kingdom. 1023 pp.
• Keay, R.W.J., 1989. Trees of Nigeria. A revised version of Nigerian trees (1960, 1964) by R.W.J. Keay, C.F.A. Onochie and D.P. Stanfield. Clarendon Press, Oxford, United Kingdom. 476 pp.
• Kokwaro, J.O., 1993. Medicinal plants of East Africa. 2nd Edition. Kenya Literature Bureau, Nairobi, Kenya. 401 pp.
• Markström, C., 1977. Plantes médicinales congolaises. Mémoire de fin d'études, Upsala, Sweden. 60 pp.
• Neuwinger, H.D., 2000. African traditional medicine: a dictionary of plant use and applications. Medpharm Scientific, Stuttgart, Germany. 589 pp.
• Normand, D. & Paquis, J., 1976. Manuel d’identification des bois commerciaux. Tome 2. Afrique guinéo-congolaise. Centre Technique Forestier Tropical, Nogent-sur-Marne, France. 335 pp.
• Olukoya, D.K., Idika, N. & Odugbemi, T., 1993. Antibacterial activity of some medicinal plants from Nigeria. Journal of Ethnopharmacology 39: 69–72.
• Oteng-Amoako, A.A. (Editor), 2006. 100 tropical African timber trees from Ghana: tree description and wood identification with notes on distribution, ecology, silviculture, ethnobotany and wood uses. 304 pp.
• van der Veken, P., 1960. Anacardiaceae. In: Robyns, W., Staner, P., Demaret, F., Germain, R., Gilbert, G., Hauman, L., Homès, M., Jurion, F., Lebrun, J., Vanden Abeele, M. & Boutique, R. (Editors). Flore du Congo belge et du Ruanda-Urundi. Spermatophytes. Volume 9. Institut National pour l’Étude Agronomique du Congo belge, Brussels, Belgium. pp. 5–108.
• White, L. & Abernethy, K., 1997. A guide to the vegetation of the Lopé Reserve, Gabon. 2nd edition. Wildlife Conservation Society, New York, United States. 224 pp.
Sources of illustration
• Aubréville, A., 1959. La flore forestière de la Côte d’Ivoire. Deuxième édition révisée. Tome deuxième. Publication No 15. Centre Technique Forestier Tropical, Nogent-sur-Marne, France. 341 pp.
• Vivien, J. & Faure, J.J., 1985. Arbres des forêts denses d’Afrique Centrale. Agence de Coopération Culturelle et Technique, Paris, France. 565 pp.
Author(s)
E. Ebanyenle
Forestry Research Institute of Ghana (FORIG), KNUST, University, P.O. Box 63, Kumasi, Ghana


Editors
R.H.M.J. Lemmens
PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands
D. Louppe
CIRAD, Département Environnements et Sociétés, Cirad es-dir, Campus international de Baillarguet, TA C-DIR / B (Bât. C, Bur. 113), 34398 Montpellier Cedex 5, France
A.A. Oteng-Amoako
Forestry Research Institute of Ghana (FORIG), University P.O. Box 63, KNUST, Kumasi, Ghana

Correct citation of this article:
Ebanyenle, E., 2009. Lannea welwitschii (Hiern) Engl. In: Lemmens, R.H.M.J., Louppe, D. & Oteng-Amoako, A.A. (Editors). Prota 7(2): Timbers/Bois d’œuvre 2. [CD-Rom]. PROTA, Wageningen, Netherlands.
Distribution Map wild


1, base of bole; 2, apex of flowering twig; 3, male flower; 4, leaf and infructescence.
Redrawn and adapted by Iskak Syamsudin