Prota 7(1): Timbers/Bois duvre 1
Journ. Linn. Soc., Bot. 55: 504 (1956).
False white ash (En).
Origin and geographic distribution
Pseudobersama mossambicensis occurs in coastal regions of Kenya, Tanzania, Mozambique and northern South Africa.
The wood is used for poles in local house building and as a general purpose timber. It is also used as fuelwood and for making charcoal.
The wood is lightweight but durable. Cytotoxic 7-hydroxy sterols have been isolated from Pseudobersama mossambicensis twigs and leaves. They showed toxicity against P-388 murine leukaemia cells, and some of them exhibited significant DNA-damaging activity.
Evergreen dioecious shrub or small to medium-sized tree up to 20 m tall; bark surface greyish; young branches reddish brown, slightly hairy. Leaves alternate, imparipinnately compound with 917 leaflets; stipules absent; petiole c. 5 cm long, rachis up to 25 cm long; petiolules up to 7 mm long; leaflets alternate to nearly opposite, elliptical to oblong-elliptical, 39(15) cm ื 14(6) cm, cuneate and often asymmetrical at base, shortly acuminate at apex, glabrescent but with tufts of hairs in vein axils below, pinnately veined. Inflorescence an axillary cyme, often head-like, short-hairy, up to 12-flowered; peduncle 16 cm long. Flowers unisexual, male and female flowers very similar in appearance, regular, 5-merous, whitish; pedicel c. 1 mm long; calyx cup-shaped, c. 3 mm long, lobed to the middle; petals free, 56 mm long; stamens 34 mm long, fused in lower half into a tube, hairy inside towards the apex; ovary superior, ovoid-globose, hairy, 5-celled, style 12 mm long, stigma obscurely lobed; male flowers with rudimentary ovary, female flowers with non-dehiscing anthers. Fruit an ellipsoid to globose capsule 34.5 cm in diameter, densely covered with antler-shaped appendages c. 7 mm long, red, dehiscing with usually 5 woody valves, up to 10-seeded. Seeds c. 7 mm ื 5 mm, glossy dark brown or black, covered by a bright red aril at one side.
Pseudobersama comprises a single species and is close to Trichilia. It is characterized by its antler-shaped fruit appendages. The wood anatomy of Pseudobersama mossambicensis differs little from that of some Trichilia spp., but the vessels are more commonly solitary and fewer in number in Pseudobersama mossambicensis.
Pseudobersama mossambicensis occurs in lowland coastal forest, where it is often found in the understorey of moist forest types and in forest margins. It can be found from sea-level up to 300(500) m altitude.
Genetic resources and breeding
Pseudobersama mossambicensis has a rather limited area of distribution, and is restricted to moister forest types within this area. This might make it easily liable to genetic erosion as a result of habitat destruction, although it appears to be little used by the local populations. In South Africa it is a protected plant species.
Its usually small bole size makes it very unlikely that the future importance of Pseudobersama mossambicensis wood will exceed its actual limited usage.
Coates Palgrave, K., 1983. Trees of southern Africa. 2nd Edition. Struik Publishers, Cape Town, South Africa. 959 pp.
Gasson, P. & Cheek, M., 1992. The wood anatomy of Pseudobersama mossambicensis and Trichilia capitata (Meliaceae) compared. Kew Bulletin 47(4): 753758.
Palmer, E. & Pitman, N., 19721974. 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.
Beentje, H.J., 1994. Kenya trees, shrubs and lianas. National Museums of Kenya, Nairobi, Kenya. 722 pp.
Gunatilaka, A.A.L., Samaranayake, G., Kingston, D.G.I., Hoffmann, G. & Johnson, R.K., 1992. Bioactive ergost-5-ene-3β, 7α-diol derivatives from Pseudobersama mossambicensis. Journal of Natural Products 55(11): 16481654.
Heltzel, C.E., Gunatilaka, A.A.L., Kingston, D.G.I., Hoffmann, G.A. & Johnson, R.K., 1994. Synthesis and structure-activity relationships of cytotoxic 7-hydroxy sterols. Journal of Natural Products 57(5): 620628.
Lovett, J.C., Ruffo, C.K., Gereau, R.E. & Taplin, J.R.D., 2007. 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://www.york.ac.uk/ res/celp/webpages/projects/ecology/ tree%20guide/guide.htm. Accessed January 2008.
Mulholland, D.A., Parel, B. & Coombes, P.H., 2000. The chemistry of the Meliaceae and Ptaeroxylaceae of Southern and Eastern Africa and Madagascar. Current Organic Chemistry 4(10): 10111054.
van Wyk, B.E. & Gericke, N., 2000. Peoples plants: a guide to useful plants of southern Africa. Briza Publications, Pretoria, South Africa. 351 pp.
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. 285319.
Correct citation of this article:
Lemmens, R.H.M.J., 2008. Pseudobersama mossambicensis (Sim) Verdc. In: Louppe, D., Oteng-Amoako, A.A. & Brink, M. (Editors). Prota 7(1): Timbers/Bois duvre 1. [CD-Rom]. PROTA, Wageningen, Netherlands.