Botanical Name: Entandrophragma utile
Species: E. utile
Synonyms: Entandrophragma macrocarpum A.Chev. Entandrophragma roburoides Vermoesen Entandrophragma thomasii Le
Common Names:Sipo mahogany, Sipo or Utile
Local Names: English (sipo mahogany,mufumbi mahogany,mahogany,feather
sepele,budongo heavy mahogany,Ashanti cedar,African cedar); French
(sipo,assie,acajou); Luganda (muyovu,mukola); Trade name
Habitat: Entandrophragma utile is native to nearly all of tropical Africa facing the Atlantic. It is most commonly found in moist semi-deciduous forest, though it can also be found in evergreen forest.
Entandrophragma utile is a large tree growing up to 55 m tall with blunt buttresses. The straight, cylindrical bole is usually up to 300 cm in diameter and can be branchless for up to 50 m. Sometimes extending into large surface roots; bark surface silvery grey to greyish brown or yellowish brown, fissured and becoming scaly with elongate scales, inner bark pinkish red, fibrous, without distinct smell; crown dome-like, with few but massive branches; young twigs brownish short-hairy but soon glabrescent, marked with leaf scars. Leaves alternate, clustered near ends of twigs, paripinnately compound with (12–)14–32 leaflets; stipules absent; petiole 5–15 cm long, with 2 faint lateral ribs or slightly winged at base, rachis up to 45 cm long, slightly grooved; petiolules 1–5 mm long; leaflets opposite to alternate, oblong-elliptical to oblong-lanceolate or oblong-ovate, (3.5–)5–15 cm × (1.5–)2–5.5 cm, rounded to slightly cordate and asymmetrical at base, usually short-acuminate at apex, papery to thinly leathery, almost glabrous but with tufts of hairs in vein axils below, pinnately veined with 10–16 pairs of lateral veins. Inflorescence an axillary or terminal panicle up to 25 cm long, short-hairy. Flowers unisexual, regular, 5-merous; pedicel 2–3 mm long; calyx cup-shaped, shortly lobed, 0.5–1 mm long, short-hairy outside; petals free, ovate, 5–6 mm long, short-hairy outside, greenish white; stamens fused into an urn-shaped tube 3–4 mm long, with 10 anthers at the slightly toothed or nearly entire apex; disk cushion-shaped, small; ovary superior, conical, 5-celled, style c. 1.5 mm long, stigma disk-shaped; male flowers with rudimentary ovary, female flowers with smaller, non-dehiscing anthers. Fruit a pendulous, club-shaped capsule 14–28 cm × 4.5–7 cm, brownish black and with numerous reddish brown lenticels, dehiscing from the apex with 5 woody valves, up to 30-seeded with seeds attached to the upper part of the central column. Seeds 8–11 cm long including the large apical wing, medium to dark brown. Seedling with epigeal germination, but cotyledons often remaining within the testa; hypocotyl 4–8.5 cm long, epicotyl 2–4 cm long; first 2 leaves opposite, simple.
A tree of low to medium elevations in the moist tropics, where it can be found at elevations up to 1,400 metres. It is found mainly in regions with an annual rainfall in the range 1,400 – 2,500 mm, where there is a dry period of 2 – 4 months and a mean annual temperature of 24 – 26°c. Prefers well-drained localities on deep soils. The species is characterized as a non-pioneer light demander and is generally noted to be more light-demanding and tolerant of dry conditions than other embers of the genus. Natural regeneration is often scarce in the forest, although it has also been reported as abundant. Regeneration in large forest gaps is reportedly poor, but seedlings perform well in small forest gaps. Saplings are more light-demanding than those of other members of the genus. Young seedlings grow slowly; root development takes considerable time. In Ghana, seedlings reached only up to 1 metre tall after 4 years, in silviculturally treated forest up to 1.5 metres. Under nursery conditions, however, seedlings can reach 40 cm tall in 6 months and 75 cm in one year. Fruit production starts when trees have reached bole diameters above 50 cm, and this has implications for forest management; minimum felling diameters should be well above 50 cm to allow natural regeneration. A dioecious species, both male and female forms need to be grown if fruit and seed are required.
Seed – pre-soaking the seeds in warm water is reported to improve germination. Fresh seeds have a germination rate of about 75%, whilst that of 3-month-old seeds is still about 60%. The seeds are liable to rotting and should hardly be covered with soil. Germination starts 13 – 19 days after sowing. Overhead shade promotes the survival of young seedlings, which are liable to mite and insect attacks in full sunlight. The seedlings are physiologically well adapted to heavy shade and make efficient use of low light intensities – they usually die when growing under full light conditions. Seedlings growing in 10 – 12% of full sunlight maintained high growth rates, and an irradiance of 25% of full sunlight is recorded to optimize growth of young seedlings. When seedlings are grown in pots, it should be taken into account that they develop a long taproot; the roots should be cut back several times in the 1 – 2-year-long period that the seedlings are raised in the nursery. Seeds can be stored for about 3 months in sealed containers in a cool place, but insect damage, to which they are very susceptible, should be avoided, e.g. by adding ash. Stumps and striplings have been used for propagation, but the success rate of stumps was low.
The bark is used in traditional medicine. It is used to treat malaria and is claimed to heal peptic ulcers. The bark sap is taken internally, or used as a wash, to treat stomach-ache and kidney pain. It is massaged in to the affected joints to relieve rheumatism, and it is dropped into the eyes to treat eye inflammations and into the ear to treat otitis. A massage with a bark maceration is considered useful as tonic and stimulant. The charred and pulverized bark, mixed with salt and palm oil, is rubbed into scarifications to treat headache. Research has shown the presence of a range of medically active substances in the bark, including the lactone entandrophragmin, tetranortriterpenoids called utilins, heptanortriterpenoids called entilins, methyl angolensate and an ergosterol derivative. An aqueous bark extract has shown significant protection against peptic ulcers. This supports the traditional medicinal use of the bark against peptic ulcers in Nigeria. Bark extracts have shown fungicidal activity against Pyricularia oryzae. Some entilins have shown moderate in-vitro antimalarial activity against chloroquine-resistant strains of Plasmodium falciparum.
The fruit valves have been used as spoons. The seeds contain 30 – 54% of fat by weight. The fatty acid composition is characterized by the presence of about 30% cis-vaccenic acid, a rare isomer of oleic acid that can be used in the industrial production of nylon-11. The main fatty acid is linolenic acid (46%). The heartwood is reddish brown to purplish brown with moiré shades; it is distinctly demarcated from the 2 – 6cm wide band of pinkish white to pale brown sapwood. The grain is slightly interlocked and irregular; texture moderately fine; when seasoned it has a faint cedar-like smell. The wood is moderately heavy; soft to moderately hard; moderately durable, being moderately resistant to powder-post beetle, pinhole borer, termite and marine borer attacks. It air dries somewhat slowly, and may be liable to splitting and distortion; once dry, it is moderately stable in service. The wood saws and works fairly easily with both hand and machine tools, with only slight blunting effects on cutting edges; finishing usually gives good results, with a nice polish, but the use of a filler may be needed; it is not liable to splitting in nailing and screwing, with good holding properties; gluing, staining and polishing properties are satisfactory, but the steam bending properties are poor. The wood is highly valued for exterior and interior joinery, interior trim, panelling, stairs, furniture, cabinet work, ship building, veneer and plywood. It is suitable for construction, flooring, vehicle bodies, boxes, crates, carvings and turnery. The bole is traditionally used for dug-out canoes. Wood that can not be utilized as timber may be used as firewood and for charcoal production.
Disclaimer : The information presented herein is intended for educational purposes only. Individual results may vary, and before using any supplement, it is always advisable to consult with your own health care provider.