General Info

Tree is up to 30m high. The large imparipinnate Leaves lack stipules. The 5-merous actinomorphic Flowers are dioecious. Fruit: a dehiscing woody capsule with black Seeds with a bright aril.

Description

Tree

Trichilia dregeana, Trichilia chirindensis.

RSA No. 300.

Common names. Thunder tree, Christmas bells, Red ash, Bosrooiessenhout, Cape Mahogany, Forest Mahogany, Forest Natal Mahogany, White Mahogany.

Family: Meliaceae (Mahogany family). This family of shrubs and small trees has 50+ genera and 570+ species. In southern Africa, there are about 6 genera and 11 species including Ekebergia, Nymania, Khaya and Trichilia. Perhaps the best-known local alien tree in this family is the seringa (Melia azedarach). This tree is now considered invasive in the RSA. Most trees are evergreen and Leaves are large, simple or compound, lack stipules and are usually alternate. They occur in a large cluster or on short shoots. The bisexual or unisexual Flowers are regular, axillary and solitary. The Calyx has 4-5 sepals, which are free to near the base. The 4 Petals are imbricate (having regularly arranged, overlapping edges). The 5 to many Stamens are free except at the base and the Anthers are attached in the middle. The superior Ovary has a simple Style, which ends in a disc-like, head-like or lobed Stigma. The Fruit is a capsule or a drupe and may be winged or have a pulpy covering.

Name derivation: Trichilia – in 3 parts (referring to the 3-lobed fruits). dregeana – refers to Johan Franz Drege who visited RSA between 1826 and 1834. His story is worth reading about. He collected over 200 000 specimens in 8 000 different species. There are 2 species of the genus Trichilia in the RSA. The other one is T. emetica.

Conservation Status: LC (least concern). 2009 (Raimondo et al.).

Tree may reach 30m and rarely 40m in height. The Trunk is straight, has a diameter up to 1,8m, and may be lightly buttressed. The Crown is spreading. Bark is smooth and grey to black with a rougher base. It may be mottled with pink.

Leaves

This evergreen tree has Leaves that are large and imparipinnate (compound leaf ending in a single leaflet). Leaflets are large and have 3 to 5 pairs of opposite or alternate leaflets and a terminal one. Leaflet Blades have 8-12 pairs of lateral veins (usually less than in Trichilia emetica). These veins are more prominent and raised below. Leaflets are dark glossy green above, lighter below and up to 21 x 9cm – usually smaller. Leaflets are oblong, obovate or oblanceolate. They may be larger near the apex of the leaf. The Margin is entire (with a continuous margin, not in any way indented but may be hairy) and slightly rolled under. The Midrib and most lateral veins protrude below. Here the net veins are also clearly visible. The Apex tapers. The Base is rounded, narrowed or tapering. The Petiole (leaf stalk) is up to 15cm long and the base is thick. The thick Petiolule (leaflet stalk) is up to 1,5cm long and may be hairy (photo 312). Stipules (basal appendages of the petiole) are absent.

Flowers

The pleasantly scented Flowers occur in cymose (a cyme is a broad, more or less flat-topped, determinate flower cluster, with central flowers opening first) Panicles (indeterminate, branched inflorescence with stalked flowers). The flowers borne in axils of leaves or they may be terminal. They are large creamy white, velvety, unisexual and dioecious (having male and female parts on separate plants). Flowers are actinomorphic (regular, symmetrical. The Perianth – calyx and corolla – is divisible into 3 or more identical sectors or mirror images). The Calyx has 5 Sepals. The Corolla has 5 imbricate (having regularly arranged, overlapping edges, as roof tiles) velvety Petals up to 2,5cm long. The Disc (a more or less fleshy or elevated development of the receptacle) is fused to the base of the staminal tube. The 10 Stamens are fused near the base of the Filaments in the Male flowers. In the Female flowers, there is a single Pistil (a unit of the Gynoecium, the female element of the flower, composed of the Ovary, Style and Stigma). The superior Ovary is villous (provided with long and soft, not matted hairs). Each of the 2-4 Locules contains 1 or 2 Ovules. The villous Style is circular in cross section. The Stigma is capitate (formed like a head). (Oct-Dec).

Fruit

Fruit is up to 0, 5cm in diameter, is an almost spherical, pale green, woody Capsule (a dry fruit resulting from the maturing of a compound ovary which usually opens at maturity by one or more lines of dehiscence). It usually has 2-4 valves (separable parts of a pod; the units or pieces into which a capsule splits or divides in dehiscing). The fruit is velvety and lacking a distinct neck joining it to the stalk. The capsule dehisces revealing a bright red to scarlet fleshy aril (an appendage or outer covering of a seed and may appear as a pulpy covering) almost surrounding the black seeds. (Dec-May). The Seeds have a high fat content.

Distribution & Ecology

These Trees are common in high rainfall evergreen forests up to an altitude of 1 220m – often on mountain slopes. Location: Eastern Cape, KwaZulu-Natal – Mitchell Park has one of the largest trees, Limpopo, Mpumalanga, North West Province, Swaziland, Zimbabwe, Mozambique, Angola, DRC, Kenya, Tanzania and Ethiopia. The tree is frost sensitive. In order to stop harvesting of this species from the natural forest in Uganda (where the availability of trees is rapidly, decreasing), authorities have decided to make an effort to provide seedlings to local communities so that they can grow them on their farms. (This is similar to the action being taken with the pepper bark tree, Warburgia salutarus, in Mpumalanga). Many birds including the Purple Crested Turaco, which is the national bird of Swaziland, eat the seeds.

Ethnobotany

The Wood polishes well and is initially pink, turning a darker colour when oiled. It makes good furniture. It is used for carving and the making of traditional musical instruments and canoes. It is a good general-purpose timber but needs to be treated against insect attack. It is also used for making household implements and bats. The fatty Seeds are utilized for the industrial production of pharmaceutical products, for cosmetics, cooking, making candles and soap. After the removal of the seed coats, the seeds are edible. Parts of the Bark are toxic and used for the preparation of fish poison. If planted soon after they have developed, seeds tend to germinate well. This tree is not for small gardens.

References

Boon, R. 2010. Pooley’s Trees of eastern South Africa. Flora and Fauna Publications Trust, Durban.

Coates Palgrave, M. 2002. Keith Coates Palgrave Trees of Southern Africa, edn 3. Struik, Cape Town.

Ginn, P.J. McIlleron, W.G. Milstein, S. 1989. The Complete Book of Southern African Birds. Struik Publishers (PTY) LTD. Third impression 1991.

Lawrence, G. H. M, 1951. Taxonomy of Vascular Plants, The Macmillan Company, New York. Tenth Printing 1965.

Palmer, E. & Pitman, N. 1972. Trees of southern Africa, Balkema, Amsterdam, Cape Town.

Schmidt, S. Lotter, M. & McCleland, W. 2002. Trees and Shrubs of Mpumalanga and the Kruger National Park.

van Wyk, B. & van Wyk, P. 1997. Field guide to Trees of Southern Africa, Struik, Cape Town.

 

http://redlist.sanbi.org/species.php?species=950-1

http://www.plantzafrica.com/planttuv/trichildreg.htm

http://www.zimbabweflora.co.zw/speciesdata/species.php?species_id=133560

https://en.wikipedia.org/wiki/Trichilia_dregeana

http://tropical.theferns.info/viewtropical.php?id=Trichilia+dregeana

http://posa.sanbi.org/flora/browse.php?src=SP 

https://www.britannica.com/plant/Meliaceae

https://en.wikipedia.org/wiki/Johann_Franz_Dr%C3%A8ge