Strephonema pseudocola (PROTA)

Plant Resources of Tropical Africa Introduction

List of species

General importance
Geographic coverage Africa
Geographic coverage World
Medicinal
Timber

Strephonema pseudocola A.Chev.

distribution in Africa (wild)

Protologue: Bull. Soc. Bot. France 58: 172 (1912).

Family: Combretaceae

• Faux colatier, potopoto (Fr).

Strephonema pseudocola is native of West Africa and occurs in the forest zone of Guinea, Sierra Leone, Liberia, Côte d’Ivoire and Ghana.

In Sierra Leone the gum is applied to rheumatism as pain relief. The seed oil is used to rub the body to treat craw-craw and the head to treat lice. In Liberia a stem bark decoction is considered astringent and is taken to treat diarrhoea. In Côte d’Ivoire the stem sap or the heated gum is topically applied to treat yaws on the soles of the feet. A leaf decoction is taken, or the leaves are put in baths, to treat dropsy and oedema. A leafy twig decoction is taken as a tonic and to treat aenemia. A root decoction is taken as a diuretic, or externally applied as eye drops to treat ophthalmia and is used in vapor baths and frictions to treat oedema. A root bark decoction, together with several other medicinal plants, is taken to treat difficult childbirth. The wood (trade names: aweruku, potopoto) is used to make agricultural implements, boats, furniture, floors, joinery, tool handles, ladders, toys and sporting goods. The bark slash yields much clear watery gum, which thickens into a translucent gelatinous glue. The cotyledons resemble those of kola nut (Cola spp.), and are sometimes used as an adulterant, but they are very bitter and considered hardly edible.

The quantity of timber produced is limited and no statistics are available on its production and trade.

The heartwood is yellowish-brown to pale olive; it is not clearly demarcated from the sapwood. The grain is usually straight, texture fine. High differential shrinkage may cause twisting. The wood is relatively heavy with a density of 650–720 kg/m³ at 12% moisture content. The rates of shrinkage are high, from green to oven dry 5.7–6.0% radial and 11.1–12.5% tangential. At 12% moisture content, the modulus of rupture is 116–171 N/mm², modulus of elasticity 12,642–15,092 N/mm², compression parallel to grain 51–54 N/mm², shear 11.8 N/mm², cleavage 17–19 N/mm, Janka side hardness 7467 N, Janka end hardness 7644 N and Chalais-Meudon side hardness 4.4–4.5. The wood is strong and tough and saws fairly easily. It is prone to degrade if seasoned quickly. The log ends become gummy and the wood is not easy to work, although it gives a smooth finish. The wood glues well, but splits in nailing. It is not durable being susceptible to attacks by Lyctus borers, pinhole borers, termites and marine borers. The heartwood is resistant to preservatives.

• Evergreen, medium-sized tree up to 25(–30) m tall; bole straight, cylindrical, fairly short, usually without buttresses, crown heavily branched, spreading, already flowering when 4 m tall; bark thin, scaly, grey; slash pinkish-brown, soft brittle and gritty with large pores, becoming darker with gelatinous, gummy exudate.
• Leaves alternate, simple, sparingly toothed, sometimes entire; stipules absent; petiole up to 1.5 cm long; blade oblong or sometimes obovate, up to c. 40 cm × c. 12 cm, base cuneate, apex abruptly acuminate, glabrous, with 2 basal glands, rusty brown-haired, pinnately veined with 8–18 pairs of lateral veins; very young leaves covered with two-armed hairs and scattered glands on margins, making an indent. Inflorescence an axillary or terminal raceme, crowded towards the end of branches, many-flowered, rachis up to 12 cm long, covered with two-armed hairs; bracts 3–4 mm long.
• Flowers bisexual, regular, 5-merous; pedicel 2–6 mm long; receptacle 6–8 mm × 5–7 mm, short-hairy, brown-green; sepals 2–3 mm long; petals obovate, 5–7 mm × 3–4 mm, white, margin ciliate; stamens 10, in 2 rows, exserted for c. 10 mm, filaments white, anthers yellow; ovary semi-inferior, 2-celled, style exserted for c. 15 mm.
• Fruit irregularly globose, 4–6.5 cm × 3–4.5 cm, fleshy, brown, indehiscent, receptacle persistent, 1–2-seeded.
• Seeds ovoid, cotyledons hemispherical, fleshy, red.
• Seedling with hypogeal germination, cotyledons remaining in the fruit, first leaves scale-like.

Strephonema is restricted to the rainforests of West and Central Africa and comprises 3 species. Only Strephonema pseudocola occurs in West Africa. The other 2 species, Strephonema mannii Hook.f. and Strephonema sericeum Hook.f., occur in the humid forest of Central Africa and are up to 30 m and 45 m tall respectively. Their wood is probably also used as timber. In Gabon the stem bark of Strephonema mannii is medicinally used.

Stephonema pseudocola occurs in humid rainforest and along rivers. Flowering and fruiting is between July and February.

Stephonema pseudocola is relatively common in its distribution area, and probably not threatened by genetic erosion. In Sierra Leone it is considered an important species in forest regeneration.

Phytochemical and pharmacological research on the different plant parts, which are medicinally used, is necessary to evaluate its potential. The timber of Strephonema pseudocola is of limited use.

• 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.
• Burkill, H.M., 1985. The useful plants of West Tropical Africa. 2nd Edition. Volume 1, Families A–D. Royal Botanic Gardens, Kew, Richmond, United Kingdom. 960 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.
• Irvine, F.R., 1961. Woody plants of Ghana, with special reference to their uses. Oxford University Press, London, United Kingdom. 868 pp.
• Jongkind, C.C.H., 1995. Review of the genus Strephonema (Combretaceae). Annals of the Missouri Botanical Garden 82(4): 535–541.

• Kerharo, J. & Bouquet, A., 1950. Plantes médicinales et toxiques de la Côte d’Ivoire - Haute-Volta. Vigot Frères, Paris, France. 291 pp.
• Kryn, J.M. & Fobes, E.W., 1959. The woods of Liberia. Report 2159. USDA Forest Service, Forest Products Laboratory, Madison, Wisconsin, United States. 147 pp.
• Oteng-Amoako, A.A. (Editor), 2006. 100 tropical African timber trees from Ghana: tree description and wood identification with notes on distribution, ecology, silviculture, ethnobotany and wood uses. 304 pp.
• Sallenave, P., 1955. Propriétés physiques et mécaniques des bois tropicaux de l’Union française. Centre Technique Forestier Tropical, Nogent-sur-Marne, France. 129 pp.
• Savill, P.S. & Fox, J.E.D., 1967. Trees of Sierra Leone. Forest Department, Freetown, Sierra Leone. 316 pp.
• Takahashi, A., 1978. Compilation of data on the mechanical properties of foreign woods (part 3) Africa. Shimane University, Matsue, Japan. 248 pp.

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

Schmelzer, G.H., 2013. Strephonema pseudocola A.Chev. In: Schmelzer, G.H. & Gurib-Fakim, A. (Editors). Prota 11(2): Medicinal plants/Plantes médicinales 2. PROTA, Wageningen, Netherlands. Accessed 6 April 2025.

• See this page on the Prota4U database.