Difference between revisions of "Diospyros abyssinica (PROTA)"

Latest revision as of 16:21, 19 September 2019

Plant Resources of Tropical Africa Introduction

List of species

General importance
Geographic coverage Africa
Geographic coverage World
Medicinal
Timber
Fuel

Diospyros abyssinica (Hiern) F.White

distribution in Africa (wild)

1, tree habit; 2, twig with fruits; 3, leaf; 4, male flower. Redrawn and adapted by Achmad Satiri Nurhaman

tree (Zimbabweflora)

leaves (Zimbabweflora)

leaves (Zimbabweflora)

leaf (Zimbabweflora)

Protologue: Bull. Jard. Bot. Etat 26: 241 (1956).

Family: Ebenaceae

Synonyms

• Maba abyssinica Hiern (1873).

Vernacular names

• Black bark, giant diospyros (En).
• Mueluili, mdaa-mwitu (Sw).

Origin and geographic distribution

Diospyros abyssinica is widespread, occurring from Guinea and Mali eastward to Eritrea, Ethiopia and Kenya, and south to Angola, Zimbabwe and Mozambique.

Uses

The wood of Diospyros abyssinica is used for heavy flooring, poles, interior trim, mine props, furniture, cabinet making, masts of dhows, agricultural implements, musical instruments, tool handles, ladders, toys, novelties, pestles, mortars, golf club heads, sticks, carving and turnery. It is also in demand for loom shuttles in weaving sisal cloth in Kenya. The wood is commonly used as firewood and for charcoal production.

Various parts of the plants are used in traditional medicine. In Ghana bark and roots are used by the Krobo people against various diseases. In Mali leaf and roots decoctions are used to treat malaria and dysentery, and to promote wound healing. In Tanzania a root decoction is taken to treat leprosy.

Production and international trade

In Tanzania the wood is considered suitable for the handles of pick-axes and other tools. A yearly production of up to 20,000 axe handles has been recorded in the 1960s.

Properties

The heartwood is whitish yellow to pale grey-brown, often with irregular black streaks or entirely black in the centre; it is not distinctly demarcated from the wide, whitish to yellowish sapwood. The grain is generally straight, sometimes interlocked, texture usually fine. Freshly cut wood has an unpleasant smell.

The wood is hard, tough and moderately heavy with a density of 720–860 kg/m³ at 12% moisture content. The rates of shrinkage are moderately high, from green to 12% moisture content 3.7% radial and 6.6% tangential. The wood air dries satisfactorily, with little distortion or splitting, but with a risk of severe cupping in over 5 cm thick boards. Boards of 5 cm thick take about 5 months to air dry. The wood is liable to distortion when kiln dried and low temperature schedules are recommended. At 12% moisture content, the modulus of rupture is 114–116 N/mm², modulus of elasticity 10,800 N/mm², compression parallel to grain 51–55 N/mm², shear 17 N/mm² and Janka side hardness 5380 N.

The wood saws well, but considerable power is required and packing of large amounts of wet sawdust around the rim should be avoided. The wood works satisfactorily with hand tools. The wood planes well with standard 30° cutting angles, but for quarter-cut material with irregular grain smaller cutting angles are recommended to avoid tearing and picking-up. The wood moulds and sands satisfactorily. Nailing is difficult, and pre-boring is recommended. Mortising and boring are somewhat difficult; boring causes some checking at the exits. The wood has a low durability and is susceptible to attacks by fungi and pinhole borers and moderately susceptible to termite attack. The service life in contact with the ground is only 8–12 months. The wood is moderately resistant to impregnation with preservatives. The fine sawdust may cause dermatitis and irritation to nose and eyes, and the use of a dust extractor is recommended.

Extracts of the root bark are potent inhibitors of 15-lipoxygenase and showed distinct radical scavenging activity. The triterpenoids betulin, betulinic acid and lupeol have been isolated from Diospyros abyssinica. These compounds are known to have anti-inflammatory activity. The bisnaphthoquinones diospyrin and isodiospyrin have been isolated from the bark. They showed activity against protozoan parasites and tumours in mice, as well as inhibition of blood platelet aggregation.

Description

• Evergreen, dioecious, small to fairly large tree up to 35(–40) m tall; bole branchless for up to 18 m, straight and slender, up to 60(–75) cm in diameter, often with small buttresses; bark surface smooth in young trees, later becoming rough and scaling off in strips or oblong plates, grey to dark green, dark brown or black, inner bark thin, fibrous, yellow-brown, darkening upon exposure; crown often small and narrow, with branches at right angles to main stem; twigs pendulous and usually glabrous.
• Leaves alternate, simple and entire; stipules absent; petiole 4–8 mm long; blade elliptical to oblong-elliptical, 3–15.5 cm × 1–5.5 cm, cuneate to rounded at base, obtuse to slightly acuminate at apex, thinly leathery, shining, nearly glabrous, pinnately veined with 5–12 pairs of lateral veins.
• Inflorescence in axils of leaves or on older branchlets, in male trees a 10–18-flowered contracted cyme, in female trees a (1–)3–5(–8)-flowered fascicle.
• Flowers unisexual, regular, 3–4-merous, creamy white to yellowish, scented; pedicel 1–2 mm long; male flowers with cup-shaped calyx c. 2 mm long, corolla 5–6 mm long, deeply lobed with lobes broadly elliptical, stamens 10–15, 2–4 mm long, ovary rudimentary; female flowers with cup-shaped calyx c. 6 mm long, divided nearly to the base, corolla similar to that of male flowers, rudimentary stamens 3–4, ovary superior, conical, c. 4 mm long, 6-celled, style short.
• Fruit an ellipsoid to nearly globose berry 8–14 mm × 8–9 mm, glabrous, yellow to orange, with persistent calyx at basis and style at apex, 1(–2) seeded.
• Seed globose to ellipsoid, c. 9 mm × 6 mm, with smooth endosperm.

Other botanical information

Diospyros is a large pantropical genus of about 500 species; in tropical Africa about 90 species occur and several produce valuable timber or edible fruits. There is quite some variation in the shape, size, venation and indumentum of leaves over the enormous eco-geographical range of Diospyros abyssinica, and some of this variation resulted in the recognition of 4 subspecies. Subsp. abyssinica covers the whole distribution area of the species, the other 3 subspecies are restricted to small regions in East and southern Africa.

Anatomy

Wood-anatomical description (IAWA hardwood codes):

• Growth rings: 2: growth ring boundaries indistinct or absent.
• Vessels: 5: wood diffuse-porous; (7: vessels in diagonal and/or radial pattern); (10: vessels in radial multiples of 4 or more common); 13: simple perforation plates; 22: intervessel pits alternate; (23: shape of alternate pits polygonal); 25: intervessel pits small (4–7 μm); 30: vessel-ray pits with distinct borders; similar to intervessel pits in size and shape throughout the ray cell; (40: mean tangential diameter of vessel lumina ≤ 50 μm); 41: mean tangential diameter of vessel lumina 50–100 μm; 48: 20–40 vessels per square millimetre; (49: 40–100 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; 70: fibres very thick-walled.
• Axial parenchyma: 77: axial parenchyma diffuse-in-aggregates; 78: axial parenchyma scanty paratracheal; 86: axial parenchyma in narrow bands or lines up to three cells wide; 92: four (3–4) cells per parenchyma strand.
• Rays: 96: rays exclusively uniseriate; (97: ray width 1–3 cells); 106: body ray cells procumbent with one row of upright and/or square marginal cells; 107: body ray cells procumbent with mostly 2–4 rows of upright and/or square marginal cells; 116: ≥ 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

In general Diospyros abyssinica is reported to grow slowly, but in Uganda it seems to be able to grow faster when planted in farmland. Trees have a full crown of leaves through the dry season, but most individuals drop their leaves during the wet season when new flushes appear. Fruits ripen about 3 months after flowering. They are eaten by various animals, such as baboons in Ghana, bulbuls in Malawi and hornbills in Zimbabwe; these may serve as seed dispersers.

Ecology

Diospyros abyssinica can be found in a wide diversity of forest types, and also in woodland and thickets. In its entire distribution area the altitudinal range is 200–2500 m and the mean annual rainfall range 650–2050 mm. However, its most characteristic habitat is moist semi-deciduous forest with well-distributed rainfall between 1250 and 1500 mm/year. Its presence in drier areas depends on the availability of water along watercourses, from runoff from rocky outcrops, or in water-retaining soils of termite mounds.

Propagation and planting

Usually Diospyros abyssinica is considered a pioneer species that is particularly characteristic for the early stages of forest succession, but may persist in old forest and may even regenerate there under shady conditions. However, light is reported to have a positive influence on seed germination and seedling growth. Seedlings are often common close to mother trees, but mortality is considered to be high.

Diospyros abyssinica is only propagated by seeds. One kg contains 2500–3000 seeds. Germination is slow. In a test in Kenya, 12% of fresh seeds had germinated after 3 weeks and 20% after 7 weeks. Seeds can be stored for several years if they are protected from insects. Ash is added to reduce insect damage. Pre-treatment of seeds before sowing is not necessary. Wildlings are sometimes used for planting.

Management

Diospyros abyssinica trees can be managed by pruning, pollarding and coppicing.

Diseases and pests

In mature trees, butt rot seems common. The fruits of Diospyros abyssinica are susceptible to attacks by the Mediterranean fruit fly (Ceratitis capitata), which is a pest of many fruit crops.

Genetic resources

In view of its wide distribution in tropical Africa and its occurrence in various habitats, Diospyros abyssinica does not seem to be threatened by genetic erosion. However, in many regions in West Africa it is uncommon. There are no indications of overexploitation or unsustainable usage.

Prospects

The wood of Diospyros abyssinica is presently not commercially important. The heartwood has not the dark colour and high durability of other Diospyros spp., but the wood is locally important for domestic uses. The medicinal properties are promising and more research is recommended on pharmacological activities in relation to drug development.

Major references

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

• Dale, I.R. & Greenway, P.J., 1961. Kenya trees and shrubs. Buchanan’s Kenya Estates Limited, Nairobi, Kenya. 654 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.

• Keay, R.W.J., 1989. Trees of Nigeria. A revised version of Nigerian trees (1960, 1964) by Keay, R.W.J., Onochie, C.F.A. & Stanfield, D.P. Clarendon Press, Oxford, United Kingdom. 476 pp.

• Maiga, A., Malterud, K.E., Diallo, D. & Paulsen, B.S., 2006. Antioxidant and 15 lipoxygenase inhibitory activities of the Malian medicinal plants Diospyros abyssinica (Hiern) F. White (Ebenaceae), Lannea velutina A. Rich. (Anacardiaceae) and Crossopteryx febrifuga (Afzel.) Benth. (Rubiaceae). Journal of Ethnopharmacology 104: 132–137.

• Noad, T. & Birnie, A., 1989. Trees of Kenya. A fully illustrated field guide. Nairobi, Kenya. 281 pp.

• Coates Palgrave, K., 1983. Trees of southern Africa. 2nd Edition. Struik Publishers, Cape Town, South Africa. 959 pp.

• White, F., 1983. Ebenaceae. In: Launert, E. (Editor). Flora Zambesiaca. Volume 7, part 1. Flora Zambesiaca Managing Committee, London, United Kingdom. pp. 248–300.

• White, F., 1988. The taxonomy, ecology and chorology of African Ebenaceae II. The non-Guineo-Congolian species of Diospyros (excluding sect. Royena). Bulletin du Jardin Botanique National de Belgique 58: 325–448.

Other references

• Aubréville, A., 1959. La flore forestière de la Côte d’Ivoire. Deuxième édition révisée. Tome troisième. Publication No 15. Centre Technique Forestier Tropical, Nogent-sur-Marne, France. 334 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.

• Burkill, H.M., 1994. The useful plants of West Tropical Africa. 2nd Edition. Volume 2, Families E–I. Royal Botanic Gardens, Kew, Richmond, United Kingdom. 636 pp.

• Bussmann, R.W., 2000. Germination of important East African mountain forest trees. Journal of East African Natural History 89: 101–111.

• Chikamai, B.N., Githiomi, J.K., Gachathi, F.N. & Njenga, M.G., undated. Commercial timber resources of Kenya. Kenya Forestry Research Institute (KEFRI), Nairobi, Kenya. 164 pp.

• Dakora, D.F., 1995. Plant flavonoids: Biological molecules for useful exploitation. Australian Journal of Plant Physiology 22: 87–99.

• Duncan, R.S. & Duncan, V.E., 2000. Forest succession and distance from forest edge in an Afro tropical grassland. Biotropica 32: 33–41.

• 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.

• Irvine, F.R., 1961. Woody plants of Ghana, with special reference to their uses. Oxford University Press, London, United Kingdom. 868 pp.

• Lieberman, D. & Li, M., 1992. Seedling recruitment patterns in a tropical dry forest in Ghana. Journal of Vegetation Science 3: 375–382.

• Maundu, P., Berger, D., Saitabau, C., Nasieku, J., Kipelian, M., Mathenge, S., Morimoto, Y. & Höft, R., 2001. Ethnobotany of the Loita Maasai. Towards community management of the forest of the Lost Child. Experiences from the Loita Ethnobotany Project. UNESCO People and Plants Working Paper 8, Paris, France. 34 pp.

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

• Odlo, K., 2009. Diospyros abyssinica. The Malian medicinal plants project, Global health research Norway-Mali. [Internet] http://folk.uio.no/ ingvilau/Plants.html. September 2009.

• Swaine, M.D., Lieberman, D. & Hall, J.B., 1990. Structure and dynamics of a tropical dry forest in Ghana. Vegetatio 88: 31–51.

• Widodo, S.H., 2001. Crescentia L. In: van Valkenburg, J.L.C.H. & Bunyapraphatsara, N. (Editors). Plant Resources of South-East Asia No 12(2): Medicinal and poisonous plants 2. Backhuys Publishers, Leiden, Netherlands. pp. 191–194.

• White, F., 1956. Notes on the Ebenaceae II. Diospyros piscatoria and its allies. Bulletin du Jardin Botanique de l’Etat (Bruxelles) 26: 277–307.

• White, F., 1983. Ebenaceae. In: Launert, E. (Editor). Flora Zambesiaca. Volume 7, part 1. Flora Zambesiaca Managing Committee, London, United Kingdom. pp. 248–300.

• White, F., 1987. Ebenaceae. In: Bamps, P. (Editor). Flore d’Afrique centrale. Spermatophytes. Jardin botanique national de Belgique, Brussels, Belgium. 103 pp.

• White, F., 1988. The taxonomy, ecology and chorology of African Ebenaceae II. The non-Guineo-Congolian species of Diospyros (excluding sect. Royena). Bulletin du Jardin Botanique National de Belgique 58: 325–448.

Sources of illustration

• 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.

• Noad, T. & Birnie, A., 1989. Trees of Kenya. A fully illustrated field guide. Nairobi, Kenya. 281 pp.

• White, F., 1987. Ebenaceae. In: Bamps, P. (Editor). Flore d’Afrique centrale. Spermatophytes. Jardin botanique national de Belgique, Brussels, Belgium. 103 pp.

Author(s)

• E.A. Obeng, Forestry Research Institute of Ghana (FORIG), University P.O. Box 63, KNUST, Kumasi, Ghana

Correct citation of this article

Obeng, E.A., 2010. Diospyros abyssinica (Hiern) F.White. [Internet] Record from PROTA4U. Lemmens, R.H.M.J., Louppe, D. & Oteng-Amoako, A.A. (Editors). PROTA (Plant Resources of Tropical Africa / Ressources végétales de l’Afrique tropicale), Wageningen, Netherlands.

Accessed 23 December 2024.

• See the Prota4U database.