Uapaca mole (PROTA)

Plant Resources of Tropical Africa Introduction

List of species

General importance
Geographic coverage Africa
Geographic coverage World
Medicinal
Timber

Uapaca mole Pax

Protologue: Bot. Jahrb. Syst. 19: 79 (1894).

Family: Euphorbiaceae (APG: Phyllanthaceae)

Chromosome number: 2n = 26

Synonyms

• Uapaca paludosa Aubrév. & Leandri (1935).

Vernacular names

• Rikio des marais, rikio à grandes feuilles (Fr).

Origin and geographic distribution

Uapaca mole occurs from Liberia east to Uganda and Tanzania, and south to Cabinda (Angola).

Uses

The wood is used for joinery, boxes and kitchen utensils. It is suitable for construction, flooring, mine props, ship building, vehicle bodies, furniture, railway sleepers and vats. In Ghana it is considered a good firewood, and it is also used to produce charcoal.

In Congo a root infusion is taken to treat headache caused by fever. Crushed roots are applied as an embrocation to ease pain. A root infusion is considered expectorant and taken to treat a blocked nose and pulmonary afflictions. Bark decoctions are drunk to treat female sterility, dysentery and food-poisoning. They are used as a mouth wash to treat toothache, as a vapour bath to treat rheumatism and oedema, as an enema to treat piles, and in baths to strengthen rachitic and premature children. Pulped leaves or stem bark with palm oil are applied to furuncles to mature them and also to treat migraine and rheumatism.

The fruits are edible and taste like avocado.

Properties

The heartwood is pale pink to pale red and not distinctly demarcated from the sapwood. The grain is often wavy to interlocked, texture moderately coarse. Quarter-sawn surfaces show an attractive stripy figure.

The wood is medium-weight, with a density of about 760 kg/m³ at 12% moisture content. It air dries fairly well with little splitting or warping, although the rates of shrinkage are quite high, from green to oven dry 5.9–6.3% radial and 11.3–12.8% tangential.

At 12% moisture content, the modulus of rupture is 133–175 N/mm², modulus of elasticity 17,840 N/mm², compression parallel to grain 54–57 N/mm², shear 10.5 N/mm², cleavage 25 N/mm and Chalais-Meudon side hardness 2.6.

The wood is rather difficult to saw and work, particularly dried wood; it contains silica. It is recommended to use stellite-tipped saw teeth and tungsten-carbide tipped cutting edges. The wood planes to a smooth surface. It holds nails and screws well, but pre-boring is necessary. It is moderately durable, being quite resistant to fungi and dry-wood borers, and moderately resistant to termites and marine borers. It is moderately resistant to impregnation with preservatives.

Ethanolic and dichloromethane bark extracts showed moderate antiplasmodial activity in vitro.

Description

Deciduous, dioecious, small to medium-sized tree up to 20(–40) m tall; bole often fluted, up to 75 cm in diameter, usually on stilt roots up to 4 m high; bark surface grey; crown much-branched; twigs reddish brown short-hairy, becoming glabrous, with conspicuous leaf scars. Leaves arranged spirally, crowded towards the end of the branches, simple and entire; stipules ovate-lanceolate to ovate-spatulate, often slightly asymmetrical, leaf-like, (0.5–)1–3 cm long, persistent; petiole (1.5–)3–6(–9) cm long, robust; blade obovate-elliptical, 9–30(–50) cm × 4–17(–30) cm, base cuneate to rounded or slightly cordate, apex usually rounded, thick-papery to thin-leathery, short-hairy on veins below, pinnately veined with (8–)9–12(–20) pairs of lateral veins. Male inflorescence an axillary globose to ovoid head 8–10 mm in diameter, with peduncle 1–2.5 cm long and up to 12 yellowish bracts up to 1 cm long; female flowers solitary. Flowers unisexual, 4–5-merous, petals usually absent; male flowers sessile, with calyx lobes up to 1.5 mm long, stamens free, c. 2 mm long, rudimentary ovary c. 1 mm long, short-hairy; female flowers with 1–2 cm long pedicel, calyx shallowly cup-shaped with triangular to rounded lobes c. 1 mm long, short-hairy, ovary superior, globose, 3–4 mm in diameter, 3(–4)-celled, slightly hairy, styles 3, 3–4.5 mm long, reflexed, 5–6-fid towards apex. Fruit an ovoid-globose drupe 2–3 cm in diameter, slightly rough, sparingly short-hairy, greenish becoming brown, with 3(–4) stones, each stone 1-seeded. Seedling with epigeal germination; hypocotyl 8–9 cm long, channeled, epicotyl c. 2 cm long, finely hairy; cotyledons rounded, up to 3.5 cm wide; first leaves alternate.

Other botanical information

Uapaca comprises about 50 species from tropical Africa and Madagascar, and is in need of a complete revision.

The fruits are eaten by birds such as turacos, and by fruit bats, monkeys, chimpanzees, gorillas and elephants, which all may disperse the seeds.

Uapaca staudtii

Uapaca staudtii Pax resembles Uapaca mole in having distinct stipules, but these are ear- or cap-shaped; moreover, it has comparatively narrower leaves and slightly hairy fruits. It is a small to medium-sized tree up to 25 m tall, occurring in riverine and swamp forest from Nigeria to Gabon. The reddish brown wood is used for joinery, interior trim, furniture and railway sleepers. It is also used for charcoal production. The fruits are edible.

Uapaca vanhouttei

Uapaca vanhouttei De Wild. (synonyms: Uapaca brieyi De Wild., Uapaca letestuana A.Chev.) also resembles Uapaca mole. It differs in its shorter and narrower stipules, and is a small to medium-sized tree up to 30 m tall with stilt-rooted bole up to 65 cm in diameter, occurring from southern Nigeria to DR Congo. Its purplish brown wood is medium-weight with a density of 655–795 kg/m³ at 12% moisture content, fairly hard and moderately durable, and is used for similar purposes as that of Uapaca mole, and also as firewood and for charcoal production. The bark is probably also used for similar purposes in traditional medicine, and the fruits are edible.

Ecology

Uapaca mole occurs in swamp, lakeside and riverine forest, but also in rainforest on slopes and crests as well as in well-drained valley bottoms, up to 1400 m altitude.

Management

Uapaca mole can be propagated by seed and wildlings. It can be pollarded and coppiced.

Genetic resources

There are no signs that Uapaca mole is threatened by genetic erosion.

Prospects

The wood is mainly used locally and this situation will probably not change because the stilt roots, the often poor shape of the bole and difficulties in processing the timber limit the possibilities for export. In Central Africa Uapaca mole has many medicinal uses. The antiplasmodial activity of the root bark is promising, and more research is warranted to elucidate the chemical compounds and evaluate the potential of these compounds for future medicine development.

Major references

• Bolza, E. & Keating, W.G., 1972. African timbers: the properties, uses and characteristics of 700 species. Division of Building Research, CSIRO, Melbourne, Australia. 710 pp.
• Breteler, F.J., 2012. Novitates Gabonensis 71. A new species of Uapaca (Phyllanthaceae, formerly Euphorbiaceae) from Gabon. Plant Ecology and Evolution 145(1): 129–131.
• Burkill, H.M., 1994. The useful plants of West Tropical Africa. 2nd Edition. Volume 2, Families E–I. Royal Botanic Gardens, Kew, Richmond, United Kingdom. 636 pp.
• Carter, S. & Radcliffe-Smith, A., 1988. Euphorbiaceae (part 2). In: Polhill, R.M. (Editor). Flora of Tropical East Africa. A.A. Balkema, Rotterdam, Netherlands. pp. 409–597.
• Takahashi, A., 1978. Compilation of data on the mechanical properties of foreign woods (part 3) Africa. Shimane University, Matsue, Japan. 248 pp.

Other references

• Aubréville, A., 1959. La flore forestière de la Côte d’Ivoire. Deuxième édition révisée. Tome deuxième. Publication No 15. Centre Technique Forestier Tropical, Nogent-sur-Marne, France. 341 pp.
• de Koning, J., 1983. La forêt de Banco. Part 2: La Flore. Mededelingen Landbouwhogeschool Wageningen 83–1. Wageningen, Netherlands. 921 pp.
• de la Mensbruge, G., 1966. La germination et les plantules des essences arborées de la forêt dense humide de la Côte d’Ivoire. Centre Technique Forestier Tropical, Nogent-sur-Marne, France. 389 pp.
• Fouarge, J. & Gérard, G., 1964. Bois du Mayumbe. Institut National pour l’Etude Agronomique du Congo (INEAC), Brussels, Belgium. 579 pp.
• Hawthorne, W.D., 1995. Ecological profiles of Ghanaian forest trees. Tropical Forestry Papers 29. Oxford Forestry Institute, Department of Plant Sciences, University of Oxford, United Kingdom. 345 pp.
• Hawthorne, W. & Jongkind, C., 2006. Woody plants of western African forests: a guide to the forest trees, shrubs and lianes from Senegal to Ghana. Kew Publishing, Royal Botanic Gardens, Kew, United Kingdom. 1023 pp.
• Mbatchi, S.F., Mbatchi, B., Banzouzi, J.T., Bansimba, T., Nsonde Ntandou, G.F., Ouamba, J.M., Berry, A. & Benoit-Vical, F., 2006. In vitro antiplasmodial activity of 18 plants used in Congo Brazzaville traditional medicine. Journal of Ethnopharmacology 104(1–2): 168–174.
• Vivien, J. & Faure, J.J., 1985. Arbres des forêts denses d’Afrique Centrale. Agence de Coopération Culturelle et Technique, Paris, France. 565 pp.
• Vivien, J. & Faure, J.J., 1996. Fruitiers sauvages d’Afrique: espèces du Cameroun. Ministère Français de la Coopération, Paris, France & CTA, Wageningen, Netherlands. 416 pp.
• White, L. & Abernethy, K., 1997. A guide to the vegetation of the Lopé Reserve, Gabon. 2nd edition. Wildlife Conservation Society, New York, United States. 224 pp.

Author(s)

• G.H. Schmelzer, PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands

Correct citation of this article

Schmelzer, G.H., 2008. Uapaca mole Pax. In: Lemmens, R.H.M.J., Louppe, D. & Oteng-Amoako, A.A. (Editors). Prota 7(2): Timbers/Bois d’œuvre 2., Wageningen, Netherlands. Accessed 1 April 2025.

• See the Prota4U database.