Prota 7(2): Timbers/Bois d’œuvre 2
Engl. & Prantl, Nat. Pflanzenfam., II–IV Nachtr. 1: 223 (1987).
Cassine buchananii Loes. (1893).
Origin and geographic distribution
Elaeodendron buchananii is widespread, from Sierra Leone east to Kenya and south to Malawi, Zambia and Angola.
The wood is used for joinery and furniture. It is suitable for heavy construction, heavy flooring, interior trim, ship building, vehicle bodies, mine props, handles, ladders, sporting goods, toys, novelties, turnery, pattern making, veneer and plywood. The wood is also used as firewood and for charcoal production.
Leaf extracts are taken as abortifacient, oxytocic, tonic and vermifuge, and to treat fever. Leaves are chewed against diarrhoea. Root decoctions are drunk to treat digestive upsets, coughing with blood, excessive uterine bleeding and infertility. Root powder is taken to treat syphilis, and it is applied to wounds.
The heartwood is pale brown to reddish brown and distinctly demarcated from the whitish sapwood. The grain is straight or interlocked, texture moderately fine.
The wood is heavy, with a density of about 800 kg/m³ at 12% moisture content. It has a slight tendency of surface and end checking in drying. Once dry, it is stable in service. At 12% moisture content, the modulus of rupture is 128–135 N/mm², modulus of elasticity 14, 800–15,680 N/mm², compression parallel to grain 66–69 N/mm², shear 16–18 N/mm², cleavage 18 N/mm, Janka side hardness 7650 N and Janka end hardness 9065 N. The wood is fairly easy to saw, although it is hard and tough. It planes well and can be polished to a nice surface. It turns well. The wood is moderately durable. The heartwood is difficult to impregnate with preservatives, the sapwood moderately difficult.
Feeding on the leaves may cause death in livestock after dyspnoea, loss of coordination and diarrhoea. Leaves and fruits are also very poisonous to humans.
A methanol extract of the bark showed cytotoxic activity against L-1210 leukaemic cells, with elabunin, a dammarane-type triterpene, as active principle. A steroidal glycoside, buchaninoside, was isolated from the fruits; it exhibited antifeedant activity against African armyworm (Spodoptera exempta) larvae. Mutangin, a sesquiterpene of the eudesmane type, was isolated from unripe fruits and exhibited moderate antifeedant activity against larvae of the stem borer Chilo partellus.
Shrub or small to medium-sized tree up to 30 m tall; bole often irregular, up to 60 cm in diameter; bark surface becoming fissured, with many lenticels, dark grey to purplish brown; crown rounded, dense; twigs flattened to quadrangular and pale grey when young, becoming rounded and red-brown, glabrous. Leaves usually opposite, but sometimes alternate, simple; stipules small, free, caducous; petiole 0.5–1.5 cm long; blade elliptical to obovate, (5–)6.5–14(–18) cm × 2–8(–10) cm, cuneate at base, shortly acuminate to acute or obtuse at apex, margins toothed with incurved or appressed teeth, leathery, glabrous, pinnately veined with few lateral veins. Inflorescence an axillary cyme on specialized, 3–5 cm long shoots, glabrous. Flowers unisexual, regular, 4–5-merous, sweet-scented; pedicel c. 1 mm long; sepals rounded, c. 1 mm long; petals free, ovate to oblong, 1.5–2.5 mm long, spreading, white to green or yellow; stamens alternating with petals, c. 1 mm long, free; disk slightly lobed; ovary superior, ovoid-conical, c. 1 mm long, 2–3-celled, style short. Fruit an ellipsoid to globose, fleshy drupe 1.5–2 cm long, usually smooth, pale yellow to pale brown when ripe, 1-seeded.
Elaeodendron buchananii grows slowly. It has been reported that in Kenya young trees are often covered by webs made by caterpillars. The tree is evergreen and may attract livestock in the dry season, which can be problematic because of the risk of poisoning.
Elaeodendron comprises about 40 species and occurs in Asia, Australia, Central America and Africa, where 8 species are found.
The wood of Elaeodendron matabelicum Loes. (synonym: Cassine matabelica (Loes.) Steedman), a shrub or small tree up to 7(–20) m tall occurring in eastern Botswana, Zimbabwe and southern Mozambique, is used for carving utensils such as spoons. Bark and root infusions or decoctions are taken to treat excessive uterine bleeding, bloody diarrhoea and pains, and as aphrodisiac. The roots produce a yellow dye.
The whitish wood of Elaeodendron transvaalense (Burtt Davy) R.H.Archer (synonym: Cassine transvaalensis (Burtt Davy) Codd), a shrub or small tree up to 10(–15) m tall from southern Zambia, southern Angola, northern Namibia, Botswana, Zimbabwe, southern Mozambique, eastern South Africa and Swaziland, is used for implements and utensils. Bark infusions and decoctions are popular for the treatment of stomach complaints, fever, venereal diseases, kidney and bladder complaints, skin diseases, swellings, haemorrhoids, and to improve appetite. Root extracts are sometimes used for similar complaints. Leaves are chewed to treat throat problems, and a leaf decoction is drunk against poisoning. The bark has been used for tanning. The fruits are edible. Elaeodendron transvaalense is sometimes planted as ornamental tree in gardens. Extracts showed in-vitro activity against Trichomonas vaginalis, an important cause of urogenital infections.
In South Africa the brownish wood of Elaeodendron zeyheri Spreng. ex Turcz., a small tree up to 13 m tall, is used for beams and furniture. The wood has rather similar properties as that of Elaeodendron buchananii and is suitable for similar purposes. The bark has been used for tanning and dyeing, and in traditional medicine to treat snakebites. A root decoction has been used as emetic and ordeal poison. Elaeodendron zeyheri has been recorded from southern Mozambique, but is more widespread in eastern South Africa. In the literature it has been much confused with Elaeodendron croceum (Thunb.) DC. (synonym: Cassine papillosa (Hochst.) Kuntze), a shrub or small tree up to 10 m tall occurring in eastern Zimbabwe and eastern South Africa, of which the wood is probably used for similar purposes. Elaeodendron croceum is better known as a medicinal plant.
Elaeodendron buchananii occurs in dry evergreen forest, gallery forest and wooded grassland up to 2250 m altitude.
Only seeds are used for propagation. The tree can be managed by pollarding, lopping and pruning.
Genetic resources and breeding
Elaeodendron buchananii is widespread and locally common, and there are no indications that it is threatened by genetic erosion. However, local collection of the bark for medicinal purposes may threaten populations.
Elaeodendron buchananii will probably remain of some importance for its timber in areas where it is common, e.g. locally in Kenya. It is not well suited for agroforestry systems because of its slow growth and dense foliage that is poisonous to livestock.
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Correct citation of this article:
Lemmens, R.H.M.J., 2010. Elaeodendron buchananii (Loes.) Loes. In: Lemmens, R.H.M.J., Louppe, D. & Oteng-Amoako, A.A. (Editors). Prota 7(2): Timbers/Bois d’œuvre 2. [CD-Rom]. PROTA, Wageningen, Netherlands.