Difference between revisions of "Ekebergia capensis (PROTA)"

Latest revision as of 09:40, 20 March 2017

Plant Resources of Tropical Africa Introduction

List of species

General importance
Geographic coverage Africa
Geographic coverage World
Fruit
Carbohydrate / starch
Dye / tannin
Medicinal
Timber
Fuel
Ornamental
Forage / feed
Auxiliary plant
Food security
Climate change

distribution in Africa (wild)

1, flowering twig; 2, part of fruiting twig. Redrawn and adapted by Iskak Syamsudin

tree habit

young tree habit

slash and bark

inflorescence

flowers

leaves and fruits

ripe fruits and seeds

wood in transverse section

wood in tangential section

wood in radial section

Ekebergia capensis Sparrm.

Protologue: Kongl. Svenska Vetenskapsakad. Handl. 40: 282, t. 9 (1779).

Family: Meliaceae

Chromosome number: 2n = 46

Synonyms

• Ekebergia senegalensis A.Juss. (1830),
• Ekebergia rueppelliana (Fresen.) A.Rich. (1847),
• Ekebergia mildbraedii Harms (1917).

Vernacular names

• Cape ash, dog plum, mountain ash, ekebergia (En).
• Mpoto wa ndovu mkuu (Sw).

Origin and geographic distribution

Ekebergia capensis is widespread, from Senegal east to Eritrea and Ethiopia, and south to Botswana, eastern South Africa and Swaziland.

Uses

The wood is locally valued for furniture, and it is also used for light construction, poles and tool handles. It is suitable for light flooring, joinery, interior trim, ship building, vehicle bodies, sporting goods, toys, novelties, vats, food containers, boxes, crates, matches, turnery, veneer and plywood. It is also used as firewood and for charcoal production.

The bark, roots and leaves are widely used in traditional medicine. Bark decoctions, infusions and macerations are taken to treat gastritis, heartburn, dysentery, epilepsy, gonorrhoea and as vermifuge, and are applied externally to ulcers, abscesses, boils, scabies, acne, pimples and itching skin. A powder prepared with the bark is sniffed against headache, colds and sinusitis. A root decoction is taken as a diuretic and to treat kidney problems, dysentery, heartburn, headache and respiratory complaints. The root is chewed as an expectorant. Charred pulverized roots are sniffed for treatment of headache and blocked nose. Leaf macerations are used internally or externally to treat headache, fever, cough and skin complaints, and they are taken as a vermifuge. The wood is used by Zulu people to facilitate childbirth. Decoctions of various parts of Ekebergia capensis are used traditionally in central Ethiopia as an anthelmintic for the treatment of livestock. Bark and roots have been used as ordeal poisons.

In southern Africa the bark has been used for tanning. The fruit is edible but usually not much liked. The foliage is browsed by livestock in the dry season. Ekebergia capensis is planted as an ornamental, particularly as a roadside tree, but also as a garden tree for its attractively coloured fruits and for shade. It is occasionally planted for soil conservation, as a windbreak and as a shade tree in coffee and banana plantations. The flowers are a source of nectar and pollen for honey bees.

Production and international trade

The wood is only used locally and has no importance on the international market. The bark and roots are commonly sold on local markets for medicinal purposes.

Properties

The heartwood is whitish to pale pink when freshly cut, darkening to greyish white, pale pinkish brown or pale brown upon drying. It is indistinctly demarcated from the sapwood. The grain is straight, texture moderately fine to coarse. Some figure may be present on backsawn surfaces.

The wood is medium-weight to moderately heavy, with a density of 495–705 kg/m³ at 12% moisture content. It air dries rapidly and without serious degrade. Boards up to 25 mm thick can be air dried in less than one month and thin boards can be kiln dried in 6 days. The wood is moderately stable in service.

At 12% moisture content, the modulus of rupture is 55–85 N/mm², modulus of elasticity 10,800 N/mm², compression parallel to grain 28–42 N/mm², shear 10 N/mm², Janka side hardness 3600–4000 N and Janka end hardness 2890–5740 N.

The wood is easy to saw and work with both hand and machine tools. It planes to a smooth surface and takes a fair polish. It has good nailing properties, but may split occasionally. Boring and mortising do not cause problems. The wood has good veneering and moulding properties. It is not durable and is susceptible to blue stain and insect attacks. The heartwood is moderately permeable for preservatives, the sapwood permeable.

The growth of both drug-resistant and drug-sensitive strains of Mycobacterium tuberculosis was inhibited by bark extracts of Ekebergia capensis at a concentration of 0.1 mg/ml. Bark extracts showed antiplasmodial activity against both chloroquine-sensitive and chloroquine-resistant strains of Plasmodium falciparum with IC₅₀ values of less than 30 μg/ml. In-vivo tests in mice showed significant suppression of chloroquine-tolerant Plasmodium berghei by Ekebergia capensis bark and leaf extracts. Several antiplasmodial triterpenoids have been isolated from the bark. Methanol extracts of the bark showed pronounced antibacterial activity against several bacteria. The bark contains the toxic compound 8-methoxy 4-methyl coumarin. Tests on guinea-pig uterine smooth muscle showed uterotonic activity of wood extracts of Ekebergia capensis; the active compounds isolated were identified as oleanonic acid and 3-epioleanolic acid. Leaf extracts demonstrated antioxidant activity. Seed extracts showed significant in-vitro anthelmintic activity against Haemonchus contortus, supporting the traditional use as an anthelmintic for livestock in Ethiopia.

It has been reported that the bark contains about 7.2% tannin. Limonoids, terpenoids, flavonoids, steroids and phenolic compounds have been isolated from Ekebergia capensis. The seeds contain the limonoid ekebergin as main constituent.

Description

• Evergreen or sometimes semideciduous, dioecious, small to medium-sized tree up to 30 m tall; bole straight or sometimes crooked, branchless for up to 12 m, up to 100 cm in diameter, fluted or with short buttresses at base; bark surface smooth but in older trees often becoming rough and scaly, pale grey to dark grey or brownish grey, inner bark reddish, sometimes with white streaks; crown large and spreading or dense and rounded; twigs short-hairy, glabrescent, with conspicuous whitish lenticels, branchlets marked by circular leaf-scars.
• Leaves arranged spirally, clustered in lax groups at ends of branches, imparipinnately compound with 3–7(–8) pairs of leaflets; stipules absent; petiole 2.5–10 cm long, swollen at base, rachis up to 25 cm long; petiolules 2–10(–20) mm long; leaflets opposite or nearly so, elliptical to lanceolate or oblong-lanceolate, 3–13(–14.5) cm × 1.5–6 cm, cuneate to rounded and asymmetrical at base, acute or shortly acuminate at apex, margin entire, papery to thinly leathery, short-hairy or glabrous below, pinnately veined with 10–15 pairs of lateral veins.
• Inflorescence an axillary panicle up to 20 cm long, densely short-hairy.
• Flowers unisexual, male and female flowers very similar in appearance, regular, (4–)5-merous, greenish white or pinkish white, fragrant; pedicel c. 2 mm long; sepals fused at base, 1–3 mm long, short-hairy outside; petals free, 4–7 mm long, hairy outside; stamens with filaments fused into a cup-shaped tube, with usually 10 anthers inserted on the rim, ovary superior, almost globose, 2–5-celled, style 0.5–1 cm long, stout, stigma head-shaped; male flowers with rudimentary ovary, female flowers with smaller, non-dehiscing anthers.
• Fruit a globose to ellipsoid drupe 1–2(–3) cm long, pink to red-brown or deep red when ripe, with 2–4 stones, each stone usually containing 1 seed.
• Seeds with thin seed coat.
• Seedling with epigeal germination; hypocotyl 3–5 cm long, epicotyl 6–8 cm long; cotyledons fleshy, c. 1.5 cm long; first 2 leaves opposite, imparipinnately compound with 1–2 pairs of leaflets.

Other botanical information

Ekebergia comprises 3 species and is confined to the African mainland.

Ekebergia benguelensis

Ekebergia benguelensis Welw. ex C.DC. is a small tree up to 10(–13) m tall, occurring from Tanzania to Angola, Zimbabwe and Mozambique. It differs from Ekebergia capensis in its thicker twigs with inconspicuous lenticels and in its leaflets with rounded to notched apex. The wood is occasionally used, e.g. for implements and bowls. The roots are used in traditional medicine to treat painful menstruation, abdominal pain, loss of appetite and as an aphrodisiac. The powdered bark is taken against impotence, and boiled leaves are applied to the chest to treat pneumonia. The fruits are edible.

Ekebergia pterophylla

Ekebergia pterophylla (C.DC.) Hofmeyr is a small tree up to 6(–10) m tall, endemic to eastern South Africa. It is characterized by its winged leaf rachis.

Anatomy

Wood-anatomical description (IAWA hardwood codes):

• Growth rings: (1: growth ring boundaries distinct); (2: growth ring boundaries indistinct or absent).
• Vessels: 5: wood diffuse-porous; 13: simple perforation plates; 22: intervessel pits alternate; (23: shape of alternate pits polygonal); 25: intervessel pits small (4–7 μm); (26: intervessel pits medium (7–10 μm)); 30: vessel-ray pits with distinct borders; similar to intervessel pits in size and shape throughout the ray cell; 42: mean tangential diameter of vessel lumina 100–200 μm; 46: ≤ 5 vessels per square millimetre; 47: 5–20 vessels per square millimetre; 58: gums and other deposits in heartwood vessels.
• Tracheids and fibres: 61: fibres with simple to minutely bordered pits; 66: non-septate fibres present; 69: fibres thin- to thick-walled.
• Axial parenchyma: 78: axial parenchyma scanty paratracheal; 79: axial parenchyma vasicentric; 89: axial parenchyma in marginal or in seemingly marginal bands; 92: four (3–4) cells per parenchyma strand; 93: eight (5–8) cells per parenchyma strand.
• Rays: 97: ray width 1–3 cells; 104: all ray cells procumbent; 115: 4–12 rays per mm.
• Storied structure: (118: all rays storied); (122: rays and/or axial elements irregularly storied).
• Mineral inclusions: (136: prismatic crystals present); (142: prismatic crystals in chambered axial parenchyma cells).

Growth and development

The tree is fairly fast growing; growth rates of up to 1 m/year have been reported. Under favourable conditions, trees may flower abundantly every year. In the savanna zone of West Africa Ekebergia capensis flowers in the dry season. The flowers are pollinated by insects such as bees and ants. Ekebergia capensis usually has male and female flowers on separate trees (dioecious), but trees with functionally male and female flowers have been recorded. The fruits are eaten by birds and fruit bats, which may disperse the seeds; masses of seedlings are often found around birds’ drinking places. Fallen fruits are eaten by mammals such as antelopes, wild pigs, baboons and vervet monkeys. Investigations of the roots of Ekebergia capensis revealed arbuscular mycorrhizal colonization.

Ecology

In West Africa Ekebergia capensis occurs in dry forest and riverine forest on well-drained soils. In East and southern Africa it is found in montane and riverine forest at 600–3000 m altitude, but also in savanna woodland and wooded grassland, and then often on termite mounds. It prefers deep sandy soils. The rainfall range is 750–2000 mm/year.

Propagation and planting

The 1000-seed weight is 110–350 g. Fresh seeds start germinating after 4–9 weeks. In a test, 37% of fresh seeds had germinated after 4 weeks and 60% after 6 weeks. The germination rate can be as high as 90% when ripe seeds are collected from the tree, but is usually up to only 50% when the seeds are collected on the ground beneath the tree. Soaking the seeds in water for one day and subsequent scrubbing with a brush promotes germination. The seeds can be sown in trays filled with river sand or normal potting soil and should be covered with only a thin layer of soil (up to 5 mm). Seeds lose their viability rapidly and storage for long periods is difficult. However, 39% germination was recorded after 9 months of storage at 4°C, and in a test in Ethiopia the germination rate of seeds kept in dry storage for 24 months was 4%. Ekebergia capensis can also be propagated by cuttings. Tip cuttings or hardwood cuttings have been used successfully, and these can be planted in trays filled with river sand; truncheons can be planted directly into the field. Wildlings are also collected for planting.

Management

After planting, the young trees should be watered freely as they are rather susceptible to drought. They should be protected from livestock for the first 2 years.

Diseases and pests

In South Africa pink disease caused by Corticium salmonicolor has been recorded in Ekebergia capensis trees, characterized by stem and branch cankers covered with cracked bark and abundant pink mycelial growth. In Nigeria larvae of the moth Bunaea alcinoe may seriously defoliate Ekebergia capensis, which seems to be its preferred host in southern Nigeria.

Handling after harvest

Logs should be removed from the forest immediately after felling because they are very susceptible to blue stain and insect attacks. The wood should be treated with preservatives and anti-stain solution immediately after drying.

Genetic resources

Ekebergia capensis is very widespread, shows a remarkably wide habitat adaptation and is quite common in many regions. Therefore, there is no reason to consider it as threatened with genetic erosion. However, in Uganda and parts of Ethiopia it is considered threatened. Considering its wide variability, the collection of germplasm and mapping the genetic variation are warranted.

Prospects

For a multipurpose tree of such wide occurrence, surprisingly little is known on growth, propagation and management of Ekebergia capensis in cultivation. Given its wide ecological adaptation and apparently fair growth rates, it deserves wider testing in agroforestry systems. Although its wood is not particularly valuable, wider planting for timber production is a serious option. Several interesting pharmacological activities have been demonstrated, which may serve as a basis for the development of drugs.

Major references

• Arbonnier, M., 2004. Trees, shrubs and lianas of West African dry zones. CIRAD, Margraf Publishers Gmbh, MNHN, Paris, France. 573 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., 1997. The useful plants of West Tropical Africa. 2nd Edition. Volume 4, Families M–R. Royal Botanic Gardens, Kew, Richmond, United Kingdom. 969 pp.

• Grace, O.M., Prendergast, H.D.V., Jäger, A.K. & van Staden, J., 2002. Bark medicines in traditional healthcare in KwaZulu-Natal, South Africa: an inventory. South African Journal of Botany 69(3): 301–363.

• Palmer, E. & Pitman, N., 1972–1974. Trees of southern Africa, covering all known indigenous species in the Republic of South Africa, South-West Africa, Botswana, Lesotho and Swaziland. 3 volumes. Balkema, Cape Town, South Africa. 2235 pp.

• Styles, B.T. & White, F., 1991. Meliaceae. In: Polhill, R.M. (Editor). Flora of Tropical East Africa. A.A. Balkema, Rotterdam, Netherlands. 68 pp.

• Takahashi, A., 1978. Compilation of data on the mechanical properties of foreign woods (part 3) Africa. Shimane University, Matsue, Japan, 248 pp.

• van Wyk, B.E., van Oudtshoorn, B. & Gericke, N., 1997. Medicinal plants of South Africa. Briza Publications, Pretoria, South Africa. 304 pp.

• World Agroforestry Centre, undated. Agroforestree Database. [Internet] World Agroforestry Centre (ICRAF), Nairobi, Kenya. http://www.worldagroforestry.org/Sites/TreeDBS/aft.asp. February 2007.

Other references

• Beentje, H.J., 1994. Kenya trees, shrubs and lianas. National Museums of Kenya, Nairobi, Kenya. 722 pp.

• Bouquet, A. & Debray, M., 1974. Plantes médicinales de la Côte d’Ivoire. Travaux et Documents No 32. ORSTOM, Paris, France. 231 pp.

• Bryce, J.M., 1967. The commercial timbers of Tanzania. Tanzania Forest Division, Utilisation Section, Moshi, Tanzania. 139 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.

• Dlamini, M.D., 2004. Ekebergia capensis. [Internet] South African National Biodiversity Institute, Cape Town, South Africa. http://www.plantzafrica.com/plantefg/ekebergcap.htm. February 2008.

• Eguale, T., Tilahun, G., Gidey, M. & Mekonnen, Y., 2006. In vitro anthelmintic activities of four medicinal plants against Haemonchus contortus. Pharmacologyonline 3: 153–165.

• 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.

• InsideWood, undated. [Internet] http://insidewood.lib.ncsu.edu/search/. May 2007.

• 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.

• Lall, N. & Meyer, J.J.M., 1999. In vitro inhibition of drug-resistant and drug-sensitive strains of Mycobacterium tuberculosis by ethnobotanically selected South African plants. Journal of Ethnopharmacology 66: 247–354.

• Latham, P., 2007. Plants visited by bees and other useful plants of Umalila, southern Tanzania. Third edition. P.Latham, DFID, United Kingdom. 216 pp.

• Maundu, P. & Tengnäs, B. (Editors), 2005. Useful trees and shrubs for Kenya. World Agroforestry Centre - East and Central Africa Regional Programme (ICRAF-ECA), Technical Handbook 35, Nairobi, Kenya. 484 pp.

• Mbuya, L.P., Msanga, H.P., Ruffo, C.K., Birnie, A. & Tengnäs, B., 1994. Useful trees and shrubs for Tanzania: identification, propagation and management for agricultural and pastoral communities. Technical Handbook 6. Regional Soil Conservation Unit/SIDA, Nairobi, Kenya. 542 pp.

• Muregi, F.W., Chhabra, S.C., Njagi, E.N.M., Lang’at Thoruwa, C.C., Njue, W.M., Orago, A.S.S., Omar, S.A. & Ndiege, I.O., 2004. Anti-plasmodial activity of some Kenyan medicinal plant extracts singly and in combination with chloroquine. Phytotherapy Research 18(5): 379–384.

• Neuwinger, H.D., 2000. African traditional medicine: a dictionary of plant use and applications. Medpharm Scientific, Stuttgart, Germany. 589 pp.

• Rabe, T. & van Staden, J., 1997. Antibacterial activity of South African plants used for medicinal purposes. Journal of Ethnopharmacology 56: 81–87.

• Sewram, V., Raynor, M.W., Mulholland, D.A. & Raidoo, D.M., 2000. The uterotonic activity of compounds isolated from the supercritical fluid extract of Ekebergia capensis. Journal of Pharmaceutical and Biomedical Analysis 24(1): 133–145.

• Sommerlatte, H. & Sommerlatte, M., 1990. A field guide to the trees and shrubs of the Imatong Mountains, southern Sudan. Deutsche Gesellschaft fur Technische Zusammmenarbeit (GTZ), Nairobi, Kenya. 372 pp.

• Staner, P. & Gilbert, G., 1958. Meliaceae. 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 7. Institut National pour l’Étude Agronomique du Congo belge, Brussels, Belgium. pp. 147–213.

• Tanzania Forest Division, 1962. Timbers of Tanganyika: Ekebergia rueppelliana (ol mokuna). Tanzania Forest Division, Utilisation Section, Moshi, Tanzania. 3 pp.

• Venter, F. & Venter, J.-A., 1996. Making the most of indigenous trees. Briza publications, Capetown, South Africa. 304 pp.

Sources of illustration

• White, F. & Styles, B.T., 1963. Meliaceae. In: Exell, A.W., Fernandes, A. & Wild, H. (Editors). Flora Zambesiaca. Volume 2, part 1. Crown Agents for Oversea Governments and Administrations, London, United Kingdom. pp. 285–319.

Author(s)

• F.S. Mairura, Kenya Tropical Soil Biology and Fertility Institute of CIAT, P.O. Box 30677, Nairobi, Kenya

Correct citation of this article

Mairura, F.S., 2008. Ekebergia capensis Sparrm. In: Louppe, D., Oteng-Amoako, A.A. & Brink, M. (Editors). PROTA (Plant Resources of Tropical Africa / Ressources végétales de l’Afrique tropicale), Wageningen, Netherlands. Accessed 22 December 2024.

• See the Prota4U database.