Tree is up to 22m high. Between the 2-foliate Leaflets is a distinctive tiny vestigial leaflet. The small, greenish bisexual Flowers, lack petals. Fruit is an indehiscent papery pod with 1 Seed.
Colophospermum mopane, Copaifera mopane, Hardwickia mopane, Copaiba mopane.
RSA Tree No. 198.
Common names: Mopane, Mopanie, Balsem Tree, Black Ironwood, White Ironwood, Butterfly Tree, Rhodesian Mahogany, Turpentine Tree, Balsem tree, Red Angola Copal.
Family: Fabaceae, Leguminosae (Pea, bean or legume family). After the Orchidaceae and the Asteraceae, the Fabaceae is the third largest Angiosperm (flowering plants) family with 700+ genera and close to 20 000 species. Local Tree genera include Acacia (Vauchellia, Senegalia), Albizia, Bauhinia, Bolusanthus, Burkea, Calpurnia, Colophospermum, Cyclopia, Erythrina, Erythrophleum, Faidherbia, Indigofera, Philenoptera and Schotia. The Fabaceae are recognisable by their fruit and by their pinnately compound Leaves. Leaves may also be simple and usually have stipules – some of which may be spinescent. Leaflets are usually entire. Flowers are bisexual and bracteate. Regular flowers usually have 4-5 sepals and the same number of petals. Irregular flowers have 4-5 sepals and 5 or less petals. Stamens have anthers that have 2 pollen sacs and there are usually at least twice the number of stamens as petals – often 10. The superior Ovary has one locule that may contain 1 or more ovules. The Stigma and Style are simple. The single carpel develops into the Fruit, which is usually a pod. The pod dehisces on both sides and may break into segments. Seeds vary.
Name derivation: Colophospermum – oily seed. mopane – from the local name of the tree. This is the only species in the genus Colophospermum.
Conservation Status: L C. (Least Concern). 2009 (Raimondo et al.).
Description. This spineless Tree is up to 22m high – but is usually much less. The very tall trees are known as cathedral trees. In the RSA, they usually range between 3-18m high forming a “mopane scrub”. Likewise, the Trunk is usually up to 1m wide. Mature Stems (main axis of the plant, the leaf and flower bearing as distinguished from the root bearing axis) are rough, dark grey to blackish and fissured lengthways (diagnostic). The Bark does flake in narrow strips and has a ropey appearance. More than one stem may develop.
Leaves. The semi deciduous tree may be without Leaves for up to 5 months. The hairless, coriaceous (leathery) leaves are oblique (slanted, unequal sided) or ovate (egg shaped) and smell of turpentine when crushed. The Petiole (leaf stalk) is up to 4cm long. The Stipules (basal appendages of the petiole) are caducous (an organ or part, which is easily detached and shed early). Between the 2 leaflet “wings” of the butterfly-like compound leaf is a small protuberance (diagnostic). This is a reduced, vestigial (stunted) terminal leaflet. The remaining opposite Leaflets are up to 8cm long and have no Petiolules (leaflet stalks). The area surrounding the junction between the “3” leaflets is a deep red colour. When viewed with a hand lens, against a strong light, translucent gland dots are visible on the 2 large leaflets. About 7-12 visible Veins radiate out from the point of attachment. The Margin is entire (with a continuous margin, not in any way indented but may be hairy). The leaves lack a Midrib (the main rib of a leaf or leaf-like part, a continuation of the petiole). The Apex tapers. The Base is markedly asymmetric and slightly lobed on the side moving away from the terminal leaflet. New leaves are pinkish.
The greenish or whitish and inconspicuous Flowers are bisexual, zygomorphic (irregular flower: when corolla is divisible into 2 equal halves in one plane only) and in short axillary Racemes (a simple elongated inflorescence with stalked flowers) or sprays up to 7cm long. The Pedicels (flower stalks) are up to 8mm long and the bracts are minute. The Calyx has 4 greenish Sepals and Petals are absent. Flowers have 20-25 free Stamens of equal length, which are substantially extended. This helps with wind pollination. The Anthers are dorsi-fixed and dehisce through longitudinal slits. The stalked, superior Ovary is compressed and glabrous (hairless). It contains a single Ovule with a lateral Style. Years may pass between flowerings. (Oct-Mar).
The flattened papery Fruit is an indehiscent Pod, which is up to 5cm long. Small reddish resin glands are present and are visible with the aid of a hand lens. Each pod contains a single Seed, which is orange or yellow when mature. Each seed is flat, usually reniform (kidney-shaped), sticky and distinctively corrugated. Seeds may germinate while still on the tree. (Mar-Jun).
Distribution & Ecology
These Trees occur found on sandy, poorly drained soils, in hot, dry, low-lying, frost-free areas. They also occur in high pH (alkaline) and alluvial soils. The 2-winged leaflets fold up in dry times to reduce water loss and, in the process, also reduce shade. The tree is commonly the dominant, even the only tree type in an area giving rise to the term Mopane woodland. Altitude range is 660 – 1 200m. The height of the trees is dependent on soil quality and other environmental factors. Trees occur in Mpumalanga – North of the Letaba River and in the northern Kruger National Park – just south of the Olifants River. They also are found in Limpopo e.g. Mapungubwe and northwards to include Botswana, Zimbabwe, Mozambique, Namibia e.g. Etosha National Park, Angola, Malawi and Zambia. In the RSA it is often shrub-like. The Leaves have high protein content. Buffalo, elephant and giraffe consume the leaves and pods. Larvae of the Foxy Emperor butterfly, (Charaxes jasius) feed on the leaves. The small cicada-like insect Arytaina mopani may be seen, and, in its larval stage has a protective waxy scale that is rich in sugar and is sought after by baboons and people. Trees are the nesting sites for Hornbills, which have a heavy bill supported by strong neck muscles and are the only birds with fused first and second (atlas and axis) neck vertebra. The sticky seeds cling to the hooves of passing animals and are often dispersed in this way.
The Sapwood is yellow but the Heartwood is hard, dense, very durable and termite resistant. The Wood is difficult to work with but implements, ornaments, furniture and musical instrument are manufactured. The wood is used as fuel. Domestic animals browse leaves. The caterpillar of the Gonometa postica moth produces a poisonous silky cocoon that has led to a new industry producing high quality silk fabric. The mopane bee (Plebina hildebrandti) is very small and can be irritating to the eyes and nose as it searches for moisture. It is, however, stingless and produces a strong dark honey. Larva of the Emperor Moth Gonimbrasia belina feed on the leaves. These larvae are up to 8 to 10cm long and about 2cm wide. Their larvae are the so-called mopane worms and they supply a vital protein supplement to man and animals. They can be dried and stored for many months. Twigs of the tree are used as toothbrushes. Milk from cattle grazing on these leaves is not adversely affected by the smell of turpentine in the leaves. Trees are grown from Seeds, which germinate easily but are susceptible to fungal attack. They usually bear flowers after about 5 years. The trees are sensitive to frost.
Bryant, C. Lombo, B. 2004. Trees of CC Africa, Double Story Books, Cape Town.
Coates Palgrave, M. 2002. Keith Coates Palgrave Trees of Southern Africa, edn 3. Struik, Cape Town.
Ginn P.J. Mcilleron W.G. and Milstein P. le S, 1989. The Complete Book of Southern African Birds. Struik, Cape Town.
Lawrence, G. H. M, 1951. Taxonomy of Vascular Plants, The Macmillan Company, New York. Tenth Printing 1965. p317.
Palmer, E. & Pitman, N. 1972. Trees of southern Africa, Balkema, Amsterdam, Cape Town. p842.
Schmidt, S. Lotter, M. & McCleland, W. 2002. Trees and Shrubs of Mpumalanga and the Kruger National Park. p184
van Wyk, B. & van Wyk, P. 1997 Field guide to Trees of Southern Africa, Struik, Cape Town. p378.