Common Name: African Teak

General Information

Milicia excelsa is a large, deciduous tree with a wide, flat crown; it can grow up to 50 metres tall[]. The straight bole can be branchless for the first 20 metres and up to 350cm in diameter[]. The bole has short buttresses[].
This tree produces one of the most valuable timbers of Africa, where it is often also planted as an ornamental and shade tree[]. In Nigeria it is planted to mark boundaries between farms or villages[]. In many parts of Africa it is considered to be a sacred tree and is frequently protected when growing near houses and in cultivated fields[].
Because of its high quality timber, this species has been greatly over-exploited in the wild, where it is becoming much rarer[]. At present its exploitation is not sustainable in most countries - it requires protection and exploitation has to be limited if it is to become sustainable[]. The plant is classified as 'Near Threatened' in the IUCN Red List of Threatened Species(1998)[].

Known Hazards

The wood and sawdust may cause dermatitis, irritation to nose and throat, and asthmatic reactions, due to the presence of the phenol chlorophorin[].

Botanical References

Range

Tropical Africa - Guinea Bissau east to Ethiopia and south to Angola, Zimbabwe and Mozambique.

Habitat

Deciduous, semi-deciduous or evergreen, primary or secondary forest, with an apparent preference for drier forest types, at elevations up to 1,200 metres. Often occurs in gallery forest and in forest islands or as lone trees in savannah regions[].

Properties

Conservation Status	Near Threatened
Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Deciduous Tree
Height	50.00 m
Self-fertile	No
Cultivation Status	Cultivated, Ornamental, Wild

Cultivation Details

A tree of moist to wet tropical forests at low to medium elevations from sea level to 1,600 metres[]. It occurs in regions with an average annual temperature of 25 - 35°c and an average annual rainfall of 1,150 - 1,900mm[]. The tree can tolerate a dry season of up to 6 months and can grow in areas with mean annual rainfall as low as 700mm provided it has access to extra water from a perennial stream or underground source[].
African teak succeeds on a large variety of soils so long as they are fertile, it is especially sensitive to low levels of potassium and phosphorus[]. Its presence is considered to be an indicator of fertile soil suitable for cultivation[]. It prefers well-drained soils and does not tolerate impeded drainage[]. It is a pioneer species, demanding intense light and unable to stand deep shade[].
Young trees grow continuously, but growth of adult trees is periodical[].
Trees are fairly fast growing - in a 6-year-old plantation some trees were over 6 metres tall, although the variability was large[]. On average it takes 130 years here for a tree to reach a trunk diameter of 80cm[].
Male trees can start flowering within 10 years from seed, but females can take 15 years[].
It takes 5 - 6 weeks from fertilization to fruit maturation. Seed dispersal is mostly by birds, bats and squirrels[].
Trees respond well to pruning and coppicing[].
In the dry season Milicia excelsa is deciduous for a short period[].
Dioecious - both male and female forms need to be grown if seed is required[].

Edible Uses

Young leaves - cooked[].

The ripe fruits are edible[].
The fruit juice is used for flavouring[].
The fruit is green, wrinkled, fleshy and resembles a fat green caterpillar[]. It is up to 7.5cm long and 2.5 cm wide[].

Medicinal

African teak is widely used in African traditional medicine.
Research has shown that chlorophorin, a phenolic compound found in the plant, has inhibitory effects on melanin biosynthesis. Its more stable derivative, hexahydrochlorophorin, may have potential for use in skin-whitening agents and for treating disturbances in pigmentation[].
Two phenolic compounds (chlorophorin and iroko) have shown in-vitro anti-amoebic activity[].
A methanol extract of the stem bark has shown in-vivo anti-inflammatory properties[].

A root decoction is taken to treat female sterility. A decoction of the root and stem bark is taken as an aphrodisiac[].

The bark is aphrodisiac, galactagogue, purgative and tonic[]. It is used to treat a wide range of conditions including cough, asthma, heart trouble, lumbago, spleen pain, stomach pain, abdominal pain, oedema, ascites, dysmenorrhoea, gonorrhoea, general fatigue, rheumatism, sprains[].
Bark preparations are externally applied to treat scabies, wounds, loss of hair, fever, venereal diseases and sprains[]. They are also applied as an enema to cure piles, diarrhoea and dysentery[].

The latex is considered to be galactagogue[]. It is taken in the treatment of stomach problems, hypertension, tumours and obstructions of the throat[].
Externally, it is applied on burns, wounds, sores and against eczema and other skin problems[].

The leaves are galactagogue[]. They are eaten to treat insanity, and a decoction is taken for the treatment of gallstones[].
Externally, leaf preparations are used in the treatment of snakebites and fever, and as eye drops to treat filariasis.

Agroforestry Uses:

The tree is used for soil improvement through its leaf mulch, and soil conservation[, ].
A natural pioneer species within its native range, supplying a high-grade timber. It could be a useful addition in reforestation projects to restore native woodland[].

Other Uses

The mature leaves have been used as sandpaper[].

The bark is used for dyeing leather and cloth[].

The bark is used for making the roofs of houses[].

The bark of young trees has been used for making loincloths[].

The heartwood is pale yellow to yellow, darkening on exposure to yellowish or greenish brown or sometimes to chocolate brown; it is clearly demarcated from the 50 - 75mm wide band of yellowish white sapwood. The grain is interlocked; texture medium to coarse; figure mottled. The wood is somewhat greasy and is odourless[].
The wood is of medium weight, moderately hard, of good durability, being resistent to fungi, dry wood borers and termites. Working properties for hand and machine tools are generally good but variable; the interlocked grain may hamper sawing and planing. The wood is rather abrasive due to the presence of hard deposits (‘iroko stones’, mainly consisting of calcium carbonate), which can blunt cutting edges. Tearing in planing can be avoided by using cutting angles of 15° or less. The wood has good nailing, screwing, mortising and gluing properties and turns easily. It finishes well, but filler is needed. The wood contains the stilbene derivative chlorophorin, which prevents oil-based paints from drying, and which corrodes metal in contact with it. Steam-bending properties of the wood are moderate[].
The wood is a highly valued commercial timber in Africa, for which demand is large. It is used for construction work, shipbuilding and marine carpentry, sleepers, sluice gates, framework, trucks, draining boards, outdoor and indoor joinery, stairs, doors, frames, garden furniture, cabinet work, panelling, flooring and profile boards for decorative and structural uses. It is also used for carving, domestic utensils, musical instruments and toys. As it is resistant to acids and bases, it is used for tanks and barrels for food and chemical products and for laboratory benches. It is used as sliced veneer but only rarely as rotary veneer[, ].
The wood is also used as firewood and for making charcoal.[].

Propagation

Seed - can be stored at room temperature for at least 12 months[]. When sown fresh it normally gives good germination rates of 90% or more within 2 - 4 weeks[]. Seeds are sown in a seedbed and transplanted to pots or nursery beds 3 weeks after germination. Seedlings should be grown under shade to limit attacks by Phytolyma spp[]. About 4 months after sowing the seedlings are around 30cm tall and ready for planting out in the field[]. Young plants transplant well[].
Stem cuttings[]. Successful propagation has been achieved using stem cuttings from 1- and 2-year-old trees, but from mature trees cuttings should be taken from coppice shoots[].
Root cuttings[].
Grafting[].

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