Botanical Name: Leplaea thompsonii
Species: Leplaea thompsonii
Synonyms: Guarea le-testui Pellegr. Guarea oyemensis Pellegr. Guarea thompsonii Sprague & Hutch.
Common Name : Black Guarea or Dark bossé
Habitat: Leplaea thompsonii is native to Western tropical Africa – Liberia to Cameroon, south to Gabon, Congo and DR Congo. It grows in lowland evergreen rainforest, usually primary forest. It is most common in moist evergreen forest, especially in undisturbed forest, but it occurs also in moister types of semi-deciduous forest.
Leplaea thompsonii is an evergreen, dioecious, sub-canopy, medium-sized to fairly large tree; up to 35 to 55 metres tall; initial growth is slow. The stem is: straight, cylindrical; free of branches for up to 20 metres; fluted; up to 150 cm in diameter; sometimes with short, blunt buttresses at the base. It is in flower all year round. The plant is not self-fertile.
Suitable for: light (sandy), medium (loamy) and heavy (clay) soils, prefers well-drained soil and can grow in nutritionally poor soil. Suitable pH: mildly acid and neutral soils. It can grow in full shade (deep woodland) semi-shade (light woodland) or no shade. It prefers moist soil.
Leplaea thompsonii grows best in flat but well-drained sites. The tree is classified as a shade-bearer. In the forest, seedlings are most common in the shade, although generally less common than those of Leplaea cedrata. For proper development of seedlings, some opening of the forest canopy seems essential. Initial growth of seedlings is slow. When they are exposed to more sunlight after one year, growth may speed up. However, planted trees in Nigeria reached on average only 10 metres in height and 20 cm in diameter after 25 years, and it has been estimated that it takes about 200 years for Leplaea thompsonii trees to reach 100cm in bole diameter. Plants can flower and produce fruit all year round. A dioecious species, both male and female forms need to be grown if fruit and seed are required.
Propagation: Through seeds: Seed – best sown as soon as it is ripe because it has a short viability. Germination is rather slow, taking 20 – 35 days. Seedlings are drought sensitive.
Medicinal Uses: The bark is used in traditional medicine. A decoction of the bark is applied as an enema to treat kidney pain, bleeding after childbirth, rheumatism and leprosy. A bark maceration is taken as a strong purgative.
The heartwood is orangey brown when freshly cut, darkening to reddish brown upon exposure; it is usually distinctly demarcated from the 5 – 10cm wide band of paler sapwood. The grain is usually straight, sometimes interlocked; the texture fine; there is a slightly moire aspect. The wood is moderately heavy; moderately hard; moderately durable, being resistant to fungi and only occasionally attacked by termites and pinhole borers, but it is slightly more susceptible to attacks of powder-post beetles. It generally air dries fairly easily with little degrade, but has some tendency to checking during kiln drying; once dry it is stable in service. The wood is usually fairly easy to saw and work; it contains less silica than the wood of Leplaea cedrata, but is slightly more dense. It can be finished to a smooth surface, but there may be a slight tendency to pick up during planing of quarter-sawn material and some gum may appear at the surfaces. A cutting angle of 20° is recommended when interlocked grain is present. The wood holds nails and screws well, but may split upon nailing and pre-boring is recommended. It glues satisfactorily and takes paints, varnishes and stains well, but filling is recommended. The bending properties are usually moderate. The wood is . The heartwood is strongly resistant to impregnation, the sapwood permeable to moderately resistant. The wood is valued for house building, flooring, joinery, interior trim, panelling, doors, ship building, vehicle bodies, furniture, cabinet work, veneer and plywood. It is suitable for toys, novelties, boxes, crates, carving and turnery. Good-quality veneer can be produced by slicing. Traditionally, the wood is used for dugout canoes.
Known Hazards : The wood dust may cause irritation to the skin and mucous membranes]. The bark is used as a fish poison.
Disclaimer : The information presented herein is intended for educational purposes only. Individual results may vary, and before using any supplement, it is always advisable to consult with your own health care provider.