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Vitex grandifolia Gürke

Protologue
Bot. Jahrb. Syst. 18: 169 (1894).
Family
Verbenaceae (APG: Lamiaceae)
Chromosome number
2n = 32
Origin and geographic distribution
Vitex grandifolia occurs from Sierra Leone east to Cameroon and Gabon.
Uses
The wood is used on a local scale for light construction, drums and canoe seats. It is suitable for light flooring, joinery, interior trim, furniture, cabinet work, toys, novelties, shipbuilding, vehicle bodies, agricultural implements, boxes, crates, veneer, plywood and pulpwood. The fruits are edible and used to make an alcoholic drink. In traditional medicine the bark is used as a stomachic and to treat diarrhoea, bronchial complaints, rickets, sores and fever. Leaves are used in medications against colic, infections of the umbilical cord, toothache, rheumatism and orchitis. A tea made from the fruits is drunk as a tonic. The black juice exuding from leaves heated over a fire has been used as ink.
Production and international trade
The timber of Vitex grandifolia is used locally, although there are also reports on export to Europe from Cameroon and Gabon.
Properties
The heartwood is whitish to pale brown, darkening on exposure to brown, and indistinctly demarcated from the sapwood. The grain is usually straight, texture medium. The wood has a density of about 490 kg/m³ at 12% moisture content. The wood air-dries fairly easily, but has a tendency to cup; it may be reconditioned by steaming. The rates of shrinkage are moderately high: from green to oven dry 4.0% radial and 6.4% tangential. Once dried, the wood is moderately stable in service.
At 12% moisture content, the modulus of rupture is about 88 N/mm², modulus of elasticity 7700 N/mm², compression parallel to grain 35 N/mm², shear 8 N/mm², cleavage 15 N/mm and Chalais-Meudon side hardness 2.5.
The wood is easy to saw and work with hand and machine tools. It generally planes to a smooth surface and finishes well. The wood nails well without splitting. Veneer of good quality can be produced. The wood is moderately durable and reportedly resistant to termite attack. The sapwood is susceptible to Lyctus beetle attack. The heartwood is moderately resistant to impregnation by preservatives; the sapwood is fairly permeable.
Botany
Evergreen shrub or small to medium-sized tree up to 20 m tall; bole branchless for up to 15 m but usually much shorter, up to 60(–120) cm in diameter, often sinuous and slightly fluted at base; bark surface grey to reddish brown or greenish yellow, finely scaly, inner bark yellowish, rapidly darkening on exposure; young branches obtusely quadrangular, short-hairy or glabrous. Leaves opposite, digitately compound with 5(–7) leaflets; stipules absent; petiole 9–20 cm long, stout; petiolules up to 5(–10) mm long; leaflets obovate, 13–40 cm × 6–20 cm, acuminate at apex, entire, thin-leathery, glabrous. Inflorescence an axillary, compact cyme up to 7 cm long, many-flowered; peduncle up to 5 cm long. Flowers bisexual, zygomorphic, 5-merous; calyx 3–6 mm long, enlarging in fruit, with obscure teeth, finely hairy; corolla pale purple with yellowish limb, 15–20 mm long, finely hairy; stamens 4, inserted in the corolla tube, 2 long and 2 short; ovary superior, globose, 4-celled, glabrous but hairy at apex, style slender, curved. Fruit an ellipsoid to globose drupe 1.5–2 cm long, yellowish when ripe but later becoming black, fleshy, with woody, 4-celled stone, up to 4-seeded. Seeds without endosperm. Seedling with epigeal germination; hypocotyl 3–4 cm long, epicotyl 10–14 mm long; cotyledons thinly leathery, short-stalked; first pairs of leaves simple.
In Côte d’Ivoire Vitex grandifolia trees can be found flowering almost throughout the year and fruits mature in March to May and October.
Vitex comprises about 150 species and is pantropical with a few species in temperate regions. Approximately 60 species can be found in tropical Africa.
Ecology
Vitex grandifolia is often an understorey tree of lowland evergreen forest. In many regions it is rather uncommon, e.g. in Ghana and Gabon, but in other regions it may be locally common, especially in secondary forest, e.g. in Côte d’Ivoire and Cameroon.
Management
Seeds start to germinate 2–3 months after sowing. The germination rate may be up to 90%. In forest near Edéa (Cameroon) the average timber volume was recorded at 0.65 m³/ha. Logs are liable to blue stain attack and should be treated with preservatives or removed from the forest soon after felling.
Genetic resources and breeding
There are no reasons to consider Vitex grandifolia as threatened by genetic erosion because it is fairly widespread, at least locally common and also present in disturbed forest.
Prospects
Too little is known on ecology, growth rates and natural regeneration of Vitex grandifolia to judge its prospects as a timber tree in sustainably managed forest. However, the often poor shape and small size of the bole seem to limit its possibilities for commercial exploitation.
Major references
• 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., 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.
• Sallenave, P., 1964. Propriétés physiques et mécaniques des bois tropicaux. Premier supplément. Centre Technique Forestier Tropical, Nogent-sur-Marne, France. 79 pp.
• 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. & Aké Assi, L., 1979. Contribution au recensement des plantes médicinales de Côte d’Ivoire. Centre National de Floristique, Abidjan, Côte d’Ivoire. 358 pp.
• Akoègninou, A., van der Burg, W.J. & van der Maesen, L.J.G. (Editors), 2006. Flore analytique du Bénin. Backhuys Publishers, Leiden, Netherlands. 1034 pp.
• 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.
• de Koning, J., 1983. La forêt de Banco. Part 2: La Flore. Mededelingen Landbouwhogeschool Wageningen 83–1. Wageningen, Netherlands. 921 pp.
• 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.
• Huber, H., Hepper, F.N. & Meikle, R.D., 1963. Verbenaceae. In: Hepper, F.N. (Editor). Flora of West Tropical Africa. Volume 2. 2nd Edition. Crown Agents for Oversea Governments and Administrations, London, United Kingdom. pp. 432–448.
• Raponda-Walker, A. & Sillans, R., 1961. Les plantes utiles du Gabon. Paul Lechevalier, Paris, France. 614 pp.
Author(s)
R.H.M.J. Lemmens
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

Correct citation of this article:
Lemmens, R.H.M.J., 2008. Vitex grandifolia Gürke. In: Louppe, D., Oteng-Amoako, A.A. & Brink, M. (Editors). Prota 7(1): Timbers/Bois d’œuvre 1. [CD-Rom]. PROTA, Wageningen, Netherlands.