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Nesogordonia kabingaensis (K.Schum.) Capuron ex R.Germ.

Protologue
Fl. Congo Belge 10: 225 (1963).
Family
Sterculiaceae (APG: Malvaceae)
Synonyms
Cistanthera kabingaensis K.Schum. (1897), Cistanthera papaverifera A.Chev. (1912), Cistanthera fouassieri A.Chev. (1917), Cistanthera leplaei Vermoesen (1923), Nesogordonia papaverifera (A.Chev.) Capuron ex Keay (1958), Nesogordonia fouassieri (A.Chev.) Capuron ex N.Hallé (1961), Nesogordonia leplaei (Vermoesen) Capuron ex R.Germ. (1963).
Vernacular names
Danta, kotibé (En). Kotibé, aborbora (Fr). Kisumungu, kissinhungo (Po). Kamema (Sw).
Origin and geographic distribution
Nesogordonia kabingaensis occurs in the semi-deciduous dense forest zone extending from Sierra Leone east to northern DR Congo and western Uganda, and south to Gabon and northern Angola (Cabinda).
Uses
The wood of Nesogordonia kabingaensis, known as ‘danta’, ‘kotibé’ or ‘aborbora’, is easy to work and hard, as well as being resistant to abrasion. It is used in exterior and interior joinery, parquetry, turnery, for staircase boards, window frames, furniture, cabinets, tool handles, mallets, and also for lorry bodies, coach/wagon work and small boats. It is excellent for wood carving. In West Africa it was formerly used to make butts for rifles. The wood is suitable for making sliced veneer and plywood.
The wood is used as firewood. In Ghana and Côte d’Ivoire twigs are used as chew-sticks and the Ando people of Côte d’Ivoire use a leaf decoction to relieve dental caries.
Production and international trade
International trade in danta is limited and statistics are scarce. Export statistics for the whole of Africa are only available for 1974, when 88,000 m³ of logs and 1000 m³ of sawn wood were exported. International trade of danta appears to be more or less stable through the years. In 1994 Côte d’Ivoire exported nearly 10,000 m³ as logs and 250 m³ as veneer; Gabon exported 6200 m³ in 1994 and 7400 m³ in 1995, and in total 22,000 m³ in the period 1998–2003. Cameroon exported 250 m³ of sawn wood in 2003.
Properties
The heartwood is pale brown to purplish brown with a tendency to become lighter on exposure to light, distinctly demarcated from the pale brown to pink sapwood, which is 2–5(–10) cm thick. The grain is straight or interlocked, texture fine. Growth rings mostly distinct. The wood shows a ribbon-like figure on quarter-sawn surfaces.
The wood is moderately heavy, the density is 740–830 kg/m³ at 12% moisture content. The shrinkage rates are moderately high, from green to oven dry 5.0–6.2% radial and 6.5–9.4% tangential. The timber dries slowly, with slight risk of distortion and checking. In Côte d’Ivoire air drying of 29 mm thick boards from 64% to 16.5% moisture content took 270 days and of 50 mm thick planks from 64% to 18% moisture content about one year. Initial surface drying prior to kiln drying is recommended. Once dry, it is moderately stable in service.
At 12% moisture content, the modulus of rupture is 108–183(–231) N/mm², modulus of elasticity (7800–)10,900–16,200 N/mm², compression parallel to grain 45–75 N/mm², shear 8–16 N/mm², cleavage 13–31 N/mm, Janka side hardness 7740–9520 N and Janka end hardness 7840 N.
The wood blunts edged tools moderately rapidly. Stellite-tipped sawteeth are recommended. A cutting angle of 15–20° is recommended when planing to prevent tearing. The peeling and slicing properties are good. Treatment with steam at 100°C for 48 hours is recommended to facilitate slicing and improve the quality of veneer. The wood is easy to work. The nailing and screwing are good, but pre-boring is sometimes needed. Gluing does not cause problems. The wood takes an excellent polish and can be varnished and painted without difficulty. The bending properties are moderate.
The heartwood is moderately durable, but should not be used in contact with the ground. It is moderately resistant to fungi and termites, but resistant to dry-wood borers; the sapwood is liable to powder-post beetle attack. The heartwood is susceptible to marine borers. It is resistant to preservative treatment, absorbing less than 20 l/m³.
Adulterations and substitutes
Danta timber has often been sold in mixtures with African mahogany (Entandrophragma and Khaya spp.), although it has a higher density and finer texture.
Description
Medium-sized to large tree up to 45(–50) m tall, mostly evergreen but sometimes shortly deciduous; bole usually straight and cylindrical, branchless for up to 25 m and 80(–120) cm in diameter, with narrow buttresses up to 3 m high; bark fissured and flaking, whitish to grey or greyish brown; crown rounded to pyramidal, small; young branchlets with brown stellate hairs. Leaves alternate, slightly clustered at the end of branchlets, simple; stipules needle-shaped, 4–9 mm long, early caducous; petiole 1.5–5 cm long, pubescent; blade elliptical to obovate, 6–14.5 cm × 3–7 cm, base rounded or obtuse, apex acuminate and mucronate, margin entire or sinuate towards the apex and slightly revolute, glabrous but with few stellate hairs on midrib, lateral veins in 5–9 pairs, with domatia in vein axils below. Inflorescence an axillary, compact, (1–)2–3(–6)-flowered cyme; peduncle 2–4.5 cm long. Flowers bisexual, regular, 5-merous; pedicel 5–15 mm long, articulate; calyx lobes shortly united at base, lanceolate to ovate, 8–12 mm long, densely stellate-hairy outside; petals broadly obovate, 8–10 mm long, white or cream-coloured, glabrous; stamens 15, in 5 groups of 3; staminodes 5, linear, longer than the stamens; ovary superior, globose to obovoid, densely stellate-hairy, 5-celled, with 5 styles. Fruit an obconic capsule 2.5–3.5 cm long, 5-ridged, shortly brown hairy, up to 10-seeded. Seeds ovoid, c. 7 mm long, with an ovate, thin wing 12–16 mm long. Seedling with epigeal germination; hypocotyl 3–5 cm long; cotyledons leafy, kidney-shaped, 7–10 mm × 16–24 mm, palmately veined; first leaves elliptical, toothed.
Other botanical information
Nesogordonia comprises 18 species, of which 14 are endemic to Madagascar, 1 to Mayotte and 3 occur in tropical mainland Africa. The three species in mainland Africa are closely related. Nesogordonia holtzii (Engl.) Capuron ex L.C.Barnett & Dorr differs from Nesogordonia kabingaensis in having only 10 stamens, smaller leaves and smaller fruits. Nesogordonia perpulchra N.Hallé differs in having 25 stamens (5 groups of 5) and larger flowers; it has only been collected once in Gabon.
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; (10: vessels in radial multiples of 4 or more common); 13: simple perforation plates; 22: intervessel pits alternate; 23: shape of alternate pits polygonal; 24: intervessel pits minute ( 4 μm); 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; 41: mean tangential diameter of vessel lumina 50–100 μm; 47: 5–20 vessels per square millimetre; (48: 20–40 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; (70: fibres very thick-walled). Axial parenchyma: 77: axial parenchyma diffuse-in-aggregates; 78: axial parenchyma scanty paratracheal; 92: four (3–4) cells per parenchyma strand; 93: eight (5–8) cells per parenchyma strand. Rays: 97: ray width 1–3 cells; 106: body ray cells procumbent with one row of upright and/or square marginal cells; 115: 4–12 rays per mm; (116: 12 rays per mm). Storied structure: 118: all rays storied; 120: axial parenchyma and/or vessel elements storied; 121: fibres storied. Mineral inclusions: 136: prismatic crystals present; 142: prismatic crystals in chambered axial parenchyma cells.
(L.N. Banak, H. Beeckman & P.E. Gasson)
Growth and development
The light requirement of Nesogordonia kabingaensis increases with age and large trees are generally exposed. Trees in the bole diameter class of 30–60 cm are more abundant in logged-over forest. Burning seems to have a negative effect on regeneration. Saplings can reach a height of 1–1.5 m in 4 years and mean annual diameter increments of 0.5 cm have been recorded. The average annual diameter growth in Côte d’Ivoire and Central African Republic was recorded as 3.5 mm, in Ghana 4 mm until 50 cm log diameter and then decreasing to 2.5 mm for logs more than 70 cm in diameter. Planted trees in Côte d’Ivoire reached 17 cm stem diameter in 14 years. In semi-deciduous forest in Ghana Nesogordonia kabingaensis is represented in the upper forest story by a few individual trees and in the lower canopy by many recruits. Fruits are produced throughout the year except during the dry season. The seeds are dispersed by wind. In mature forest individual trees of up to 125 years old have been recorded.
Ecology
Nesogordonia kabingaensis occurs in dense, semi-deciduous forest with a pronounced dry season, up to 500(–1000) m altitude. Its presence in a location is often taken as an indication of fertile, base-rich soil. In West Africa it occurs in high densities in forest with Khaya ivorensis A.Chev., Celtis spp. and Triplochiton scleroxylon K.Schum. In Côte d’Ivoire 7–21 stems of more than 10 cm in diameter per ha have been reported for some forests. It avoids swampy localities, except in north-eastern DR Congo. It is common on hillsides.
Propagation and planting
One kilogramme contains approximately 25,000 seeds. Germination of seeds takes 1–3.5 weeks and the germination rate is about 75%. Light shade seems to be needed for germination and natural regeneration is best in medium-large gaps in the forest; in large forest clearings, but also in small gaps and especially in dense forest, it is poorer.
Management
Nesogordonia kabingaensis is not grown in plantations due to its shade-demanding nature when young and comparatively low growth rates. Thinning operations in natural forest may result in an increase in diameter growth of 25–50%.
Harvesting
In the Central African Republic the minimum log diameter for exploitation was 70 cm until 1999, when it was reduced to 50 cm.
Handling after harvest
Freshly cut logs sink in water and cannot be transported by river. The wood may cause occupational asthma in people who regularly work with it. They may also develop allergic skin reactions.
Genetic resources
Nesogordonia kabingaensis is vulnerable in parts of its range and subject to genetic erosion in outlying populations such as in Sierra Leone, Liberia, Cameroon, Gabon and the Central African Republic. It has been classified as vulnerable by IUCN because of over-exploitation and reduction of the natural area of distribution. It is still common in Côte d’Ivoire and Ghana, but Ghana has prohibited its export as logs and in Côte d’Ivoire it is protected by law.
Prospects
The prospects of Nesogordonia kabingaensis as a plantation tree seem limited. However, this species is still widespread and occurs locally in fairly large numbers, and its timber is of good quality. More research is recommended on growth rates and requirements for adequate natural regeneration to develop systems of its sustainable exploitation in natural forest, needed to safeguard the resources of this valuable timber species for the future.
Major references
• 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.
• Chudnoff, M., 1980. Tropical timbers of the world. USDA Forest Service, Agricultural Handbook No 607, Washington D.C., United States. 826 pp.
• CIRAD-Forêt, 1999. Kotibé. Bois et Forêts des Tropiques 157: 41–52.
• CIRAD Forestry Department, 2003. Kotibé. [Internet] Tropix 5.0. Fiche No 145.http://tropix.cirad.fr/ afr/kotibe.pdf. Accessed June 2005.
• Durrieu de Madron, L., Favrichon, V., Dupuy, B., Bar-Hen, A., Houde, L. & Maître, H.-F., 1998. Croissance et productivité en forêt dense humide: bilan des expérimentations dans le dispositif de Mopri, Côte d’Ivoire. Document Forafri 3. Cirad, Montpellier, France. 73 pp.
• Hallé, N., 1961. Sterculiacées. Flore du Gabon. Volume 2. Muséum National d’Histoire Naturelle, Paris, France. 150 pp.
• Poorter, L., Bongers, F., Kouamé, F.Y.N. & Hawthorne, W.D., 2004. Biodiversity of West African forests: an ecological atlas of woody plant species. CABI, Wallingford, United Kingdom. 521 pp.
• Richter, H.G. & Dallwitz, M.J., 2000. Commercial timbers: descriptions, illustrations, identification, and information retrieval. [Internet]. Version 18th October 2002. http://delta-intkey.com/wood/index.htm. Accessed June 2005.
• Voorhoeve, A.G., 1979. Liberian high forest trees. A systematic botanical study of the 75 most important or frequent high forest trees, with reference to numerous related species. Agricultural Research Reports 652, 2nd Impression. Centre for Agricultural Publishing and Documentation, Wageningen, Netherlands. 416 pp.
Other references
• 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.
• Barnett, L.C., 1988. Systematics of Nesogordonia Baill. (Sterculiaceae). PhD thesis, University of Texas, Austin, United States. 230 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.
• Capuron, R., 1953. Identité des genres Nesogordonia H.Bn. et Cistanthera K.Schum. et description de deux espèces nouvelles de Madagascar. Notulae Systematicae, Herbier du Museum de Paris 14: 258–263.
• Détienne, P., Oyono, F., Durrieu de Madron, J., Demarquez, B. & Nasi, R., 1998. L’analyse de cernes: applications aux études de croissance de quelques essences en peuplements naturels de forêt dense africaine. CIRAD-Forêt, Montpellier, France. 36 pp.
• Durand, P., 1977. Essai de séchage naturel: Kotibé (Nesogordonia papaverifera) epaisseur 29 et 50 mm. Essai 211–04 – Côte d’Ivoire. GERDAT-CTFT, Nogent-sur-Marne, France. 23 pp.
• Durrieu de Madron, L., Nasi, R. & Détienne, P., 2000. Accroissements diamétriques de quelques essences en forêt dense africaine. Bois et Forêts des Tropiques 263(1): 63–74.
• Farmer, R.H., 1972. Handbook of hardwoods. 2nd Edition. Her Majesty’s Stationery Office, London, United Kingdom. 243 pp.
• Germain, R. & Bamps, P., 1963. Sterculiaceae. 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 10. Institut National pour l’Étude Agronomique du Congo belge, Brussels, Belgium. pp. 205–316.
• Gozalo-Reques, F. & Pelta-Fernandez, R., 1988. Occupational asthma to an exotic wood: Nesogordonia papaverifera, danta ro kotibé. Revue des Maladies Respiratoires 5: 71–73.
• InsideWood, undated. [Internet] http://insidewood.lib.ncsu.edu/search/. Accessed May 2007.
• Simpson, W.T., 1996. Method to estimate dry-kiln schedules and specific groupings: Tropical and temperate hardwoods. Research paper FPL-RP-548, Forest Products Laboratory, Forest Service, Department of Agriculture, Madison WI, United States. 57 pp.
• Takahashi, A., 1978. Compilation of data on the mechanical properties of foreign woods (part 3) Africa. Shimane University, Matsue, Japan, 248 pp.
• UNEP-WCMC, 2004. Contribution to an evaluation of tree species using the new CITES Listing Criteria. UNEP World Conservation Monitoring Centre, Cambridge, United Kingdom. [Internet]. http://www.unep wcmc.org /species/tree_study/index.html. Accessed June 2005.
• Visser, L.E., 1975. Plantes médicinales de la Côte d’Ivoire. Mededelingen Landbouwhogeschool Wageningen 75–15, Wageningen, Netherlands. 79 pp.
• Worbes, M., Staschel, R., Roloff, A. & Junk, W.J., 2003. Tree ring analysis reveals age structure, dynamics and wood production of a natural forest stand in Cameroon. Forest Ecology and Management 173: 105–123.
Sources of illustration
• Voorhoeve, A.G., 1979. Liberian high forest trees. A systematic botanical study of the 75 most important or frequent high forest trees, with reference to numerous related species. Agricultural Research Reports 652, 2nd Impression. Centre for Agricultural Publishing and Documentation, Wageningen, Netherlands. 416 pp.
Author(s)
L.P.A. Oyen
PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands


Editors
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
M. Brink
PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands
General editors
R.H.M.J. Lemmens
PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands
L.P.A. Oyen
PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands
J.R. Cobbinah
Forestry Research Institute of Ghana (FORIG), University P.O. Box 63, KNUST, Kumasi, Ghana
Photo editor
A. de Ruijter
PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands

Correct citation of this article:
Oyen, L.P.A., 2005. Nesogordonia kabingaensis (K.Schum.) Capuron ex R.Germ. In: Louppe, D., Oteng-Amoako, A.A. & Brink, M. (Editors). Prota 7(1): Timbers/Bois d’œuvre 1. [CD-Rom]. PROTA, Wageningen, Netherlands.
Distribution Map wild


1, flowering twig; 2, fruit; 3, seed.
Redrawn and adapted by Achmad Satiri Nurhaman



wood in transverse section


wood in tangential section