Afzelia africana Sm. Intsia africana Sm. It is mostly used for its high-grade timber but has good potential to provide fodder for livestock and food. Afzelia africana is a multipurpose tree suitable for use in agroforestry systems. Afzelia africana can grow up to m high in forests and up to m in savannah Orwa et al.
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Afzelia africana Sm. Like other Afzelia spp. The wood is durable and treatment with preservatives is unnecessary, even for usage in permanent humid conditions or in localities where wood-attacking insects are abundant. This makes it an excellent wood for use in pleasure-crafts, especially for keels, stems and panels, for bridges, as well as interior fittings. For such uses it is sometimes as much in demand as teak. The wood is also valued for joinery and panelling, both interior and exterior, parquet floors, doors, frames, stairs, furniture and sporting goods.
It has been used traditionally for canoes. It is commonly used for domestic articles such as boxes, bowls, spoons, mortars and masks, and is locally popular for making drums.
It is suitable for decorative sliced veneer. Because of its good resistance to many chemical products and great dimensional stability, it is often preferred to materials like metals and synthetics for vats and precision equipment in industrial applications. The neutral pH of the wood makes it suitable for applications in contact with vulnerable objects such as antiques and old books in libraries. However, it should not be used in contact with textiles under more humid conditions because of the presence of colorants.
A red dye can be prepared from the heartwood. The wood is also used as firewood and for charcoal production. The foliage is commonly used as forage and the tree is particularly important as a source of fodder for livestock in the dry season. In many regions, Afzelia africana is one of the most important woody fodder plants. The leaves are sometimes eaten cooked as a vegetable; young leaves are mixed with grounded cereals before cooking.
The flowers are used as condiment in sauces. The tree is valued in agroforestry systems for soil improvement because the leaves are rich in nitrogen and minerals. The seed aril is edible and reportedly sweet; precaution is needed because the seed has been reported to be toxic, although it is used as soup condiment in Nigeria and is rich in oil and used as thickening agent.
The fruits have been used as castanets, seeds for necklaces and for other ornamental and ritual purposes. Afzelia africana is considered a fetish tree in many regions. Roots, bark, leaves and fruits are used in traditional medicine. Root decoctions or macerations are used to treat stomach complaints, convulsions, trypanosomiasis and hernia, and as antidote. Root powder is applied externally to treat rheumatism.
The roots have also been used in mixtures to prepare arrow poison. Bark decoctions and macerations are administered in the treatment of constipation, fever, vomiting, oedema, tachycardia, hypertension, bronchitis, lung complaints and bleedings during pregnancy, and as anodyne, diuretic, galactagogue and aphrodisiac.
Bark ash is applied externally to treat lumbago and bark powder to wounds and swellings. The bark is also used as fish poison. Leaf decoctions and macerations are taken or applied externally against dysmenorrhoea, epilepsy, oedema, migraine, stomach-ache, asthenia, trypanosomiasis and as anodyne.
Fruit preparations are taken to treat lung complaints and as aphrodisiac. Fruit ash is applied against leprosy, and as soap substitute. Twigs are used as chewing sticks. Afzelia africana is not the most important Afzelia species for the international timber market. The heartwood is orange-brown to golden brown, becoming red-brown upon prolonged exposure, sometimes with darker streaks. It is distinctly demarcated from the whitish to pale yellow, up to 8 cm wide sapwood. The grain is usually straight, occasionally interlocked, texture medium to coarse but even.
The wood is slightly glossy and dried wood has a leather-like smell upon planing. Drying usually does not cause problems, without deformation and splitting, but the wood dries rather slowly. For thick boards more than 7.
The shrinkage rates are low, from green to oven dry 2. Once dry, the wood is very stable in service. The wood saws easily when good equipment is used; it contains little silica less than 0. Some logs have gum pockets, which may cause problems in sawing by blunting saw teeth. Tungsten-carbide-tipped cutting tools are recommended in planing and moulding operations. The use of a filler is recommended to obtain smooth surfaces.
The nailing and screwing properties are satisfactory, but pre-boring is recommended to avoid splitting. Gluing usually does not cause problems.
The wood paints and varnishes well, but wood zones close to the centre of the log may contain anti-oxidant substances that slow down drying of varnish and may cause problems in painting. Sliced veneer of good quality can be produced, but the wood is not suitable for peeling.
The wood has a good reputation for its resistance to acids and alkalines. The heartwood is durable, with an excellent resistance to fungal, termite and borer attacks, but it is liable to marine borers. The sapwood is susceptible to Lyctus attack. The heartwood is resistant to impregnation with preservatives. Saw dust may cause allergic reactions, irritation of mucous membranes and asthma in wood workers.
Investigations of the fibre and vessel characteristics indicate that the wood is not suitable for the production of good-quality pulp and paper. Logs may have crevices filled with a whitish powdery substance originating from the wood vessels; the substance consists of kaempferol and derivatives. Kaempferol and its glycosides have antibacterial, antifungal and anti-inflammatory activities. Several other flavonoids have been isolated from the wood. The crude protein content of the foliage decreases significantly from the late dry season to the cool season.
Tests with goats did not show adverse effects. The oil is semi-drying, needs little purification and has a long shelf-life. It is suitable for the formulation of alkyd resin and shoe polish. Linoleic acid is the predominant fatty acid. Toxicological studies of the oil showed no detectable toxins. The presence of a cyanogenic compound may explain the reputed toxicity of the seeds. Experiments showed that flour with potential for use in pastries can be made from the seeds. Experiments with chickens showed that seeds could be fed as a good source of protein, but it was recommended to roast the seeds before feeding because they may contain phytates and alkaloids.
In a study with type II diabetic patients in Nigeria, it was shown that the incorporation of Afzelia africana seeds in the diet had hypolipidemic effects. The twigs contain high concentrations of tannin, which explains their traditional use as chewing stick. The excellent properties of Afzelia africana wood concerning dimensional stability and high natural durability are comparable to some well-known timbers such as merbau Intsia spp.
Roberty and douka Tieghemella africana Pierre. Afzelia comprises about 11 species, 7 of which occur in tropical Africa and 4 in South-East Asia. It is closely related to Intsia. Seedlings are very sensitive to fire, browsing and drought. Low branching is often the result. For proper development, trees have to grow fast enough in the rainy season to have their terminal buds out of reach of the browsing animals in the dry season.
Once this critical period has passed, young trees may grow up to 1 m per year in height. Based on studies of growth rings, the mean annual diameter growth of the bole is up to 1 cm on termite mounds and localities with rich soils in savanna regions. In year-old plantations, trees attained an average height of 16 m and a mean annual diameter growth of 0.
In savanna areas the bole of trees is usually short, rarely reaching 12 m, but in the forest it may reach large dimensions. Trees usually flower in the rainy season.
The flowers are sometimes eaten by bats. Fruits take about 6 months to ripen after flowering. They may remain on the tree for another 6 months. The seeds are dispersed by birds such as hornbills, which feed on the arils.
The roots are associated with ectomycorrhizal fungi; more than 30 species of fungi have been recorded. Afzelia africana is characteristic for the transition zone between wooded savanna and dense dry forest, and for dense semi-deciduous forest in more humid regions. It has been considered a principal component of the semi-dry forest that once covered large parts of the region from southern Senegal to Guinea.
Afzelia africana shows a wide adaptation to climatological conditions, but is most common in areas with an annual rainfall of more than mm.
In drier regions it is limited to localities with deep, well-drained but moist soils and to termite mounds. It occurs up to m altitude. Afzelia africana is found on a wide variety of soil types, often on hardpans of calcareous, sandy or ferralitic soils, on steep slopes, as well as in depressions and in regularly inundated sites.
In the driest sites, Afzelia africana has a reputation of being fairly fire resistant, but in dense forest it appears to be susceptible even to occasional fires. Afzelia africana woodland decreases and is being invaded by more fire-tolerant species when it is commonly burned. However, they rarely develop into larger saplings. In general, Afzelia africana regenerates poorly. This is often a result of regular burning of the vegetation and high predation of seedlings by animals.
The seedlings are also susceptible to drought.
Studies on the biocidal and cell membrane disruption potentials of stem bark extracts of Afzelia africana Smith. Directory of Open Access Journals Sweden. Full Text Available We had recently reported antibacterial activity in the crude extract of the stem bark of Afzelia africana Akinpelu et al. In this study, we assessed the biocidal and cell membrane disruption potentials of fractions obtained from the crude extract of the plant. The aqueous AQ and butanol BL fractions exhibited appreciable antibacterial activities against the test bacteria.
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We are working on a subset of plants in the PFAF database identified as having the most potential for inclusion in such designs. We are adding search terms and icons to those plants pages, and providing a range of search options aligned to categories of plants and crop yields, with Help facilities including videos. A deciduous tree in the Fabaceae family that can grow up to 10 — 25 meters tall and up to 40cm in diameter, African mahogany or Lucky bean tree Aflezia africana is known for its very good quality wood that can be used as substitute for mahogany. The fruits, particularly the fleshy pulp in the seedpod or the aril, and leaves are edible.