Croton sylvaticus (PROTA)

Plant Resources of Tropical Africa Introduction

List of species

General importance
Geographic coverage Africa
Geographic coverage World
Medicinal
Timber
Fuel
Ornamental
Forage / feed
Auxiliary plant

Croton sylvaticus Hochst. ex Krauss

Protologue: Flora 28: 82 (1845).

Family: Euphorbiaceae

Synonyms

• Croton oxypetalus Müll.Arg. (1864).

Vernacular names

• Forest croton, fever tree, forest fever berry (En).
• Msinduzi (Sw).

Origin and geographic distribution

Croton sylvaticus occurs from Guinea east to Ethiopia and south to Zimbabwe, Mozambique and South Africa (Natal).

Uses

In Central and East Africa a leaf infusion is taken as a purgative, while in Gabon the seed and seed oil are taken as a strong purgative. A bark or root decoction is taken to treat tuberculosis, fever, digestive problems and abdominal pain. Charred, powdered bark is rubbed onto bleeding gums. In Kenya a stem bark extract is taken to treat malaria. In southern Africa a bark decoction is taken to treat rheumatism; bark powder is rubbed on cuts and inflammations. In South Africa the bark is used to treat abdominal disorders, dropsy, fever and uterus problems. The bark is also used as a fish poison. In cattle the powdered bark is used as a remedy for gall bladder problems. In DR Congo wood scrapings are rubbed on the feet to treat elephantiasis. The pounded roots are used as poultice on swellings. In East Africa a leaf decoction is used as a wash to treat oedema caused by kwashiorkor and tuberculosis. In South Africa the juice of young leaves is used to treat ear infections. A leaf poultice is externally applied to treat tuberculosis.

In Zimbabwe Croton sylvaticus is sometimes cultivated as a garden ornamental. In Central and East Africa it is used as shade tree in coffee plantations and other crops. Edible caterpillars feed on the leaves and the flowers are attractive to bees. It is a useful timber tree with soft, easily workable wood, which is used to make furniture, shelves, beehives, drums, tool handles, poles and fruit boxes. The wood burns even when green, and is also used to make charcoal.

Production and international trade

The bark is one of the most commonly stocked products in Witwatersrand (South Africa). No information is available on amounts traded or prices. In 2006, 5 seeds were sold for about US$ 11 on the internet.

Properties

The seed contains an oil composed of palmitic acid, stearic acid and linoleic acid; it also contains the rare tiglic acid (2-methyl,2-butenoic acid or 2,3-dimethylacrylic acid). A glutarimide alkaloid isolated from the stem bark showed moderate toxicity in the brine shrimp test. The bark is strongly aromatic, and yields 2.7% tannins. Dichloromethane and methanol extracts of different parts of Croton sylvaticus show mutagenicity or DNA damage in in-vitro tests. Aqueous and methanol extracts of the stem bark showed anti-inflammatory and anti-oxidant activities in vitro.

Description

Monoecious, semi-deciduous shrub or small to medium-sized tree up to 25(–40) m tall; bole cylindrical, up to 100 cm in diameter; bark smelling of black pepper, grey to greenish brown, smooth; inner bark pale brown with brown streaks; crown open; young twigs sparingly to densely stellate hairy, later almost glabrous and dark grey-brown. Leaves alternate, simple; stipules linear, up to 10 mm long, soon falling; petiole up to 7 cm long, thickened at both ends; blade ovate, elliptical-ovate to ovate-lanceolate, 3–21 cm × 2–14 cm, base cuneate to rounded, with 2 stalked or sessile glands, apex acuminate, margins glandular-toothed, young leaves stellate hairy, later almost glabrous on both sides. Inflorescence an upright, terminal raceme 6–21 cm long, with either only male or female flowers or mixed and then with male flowers in upper part and 1-several female flowers at base. Flowers unisexual, 5-merous; male flowers with pedicel 2–6 mm long, sepals elliptical-ovate to ovate-lanceolate, 2–3 mm long, pale yellowish green, petals elliptical-lanceolate to oblong-lanceolate, 2–3 mm long, whitish yellow to greenish cream, stamens 14–17, free; female flowers with pedicel 1–2 mm long, stout, sepals linear-lanceolate, c. 3 mm long, whitish, petals absent or 5, linear, c. 2 mm long, greenish, ovary superior, rounded, densely stellate hairy, 3-celled, styles 3, 2-fid to base, 4–5 mm long, twisted and curved. Fruit a rounded to ellipsoid drupe 9–11 mm × 7–10 mm, slightly 3-lobed, partly or not dehiscent, stellate hairy, apex centrally depressed, salmon-pink, orange or yellow, 3-seeded. Seeds ellipsoid, c. 6 mm × 4–5 mm, flattened, whitish, aril white. Seedling with epigeal germination.

Other botanical information

Croton comprises about 1200 species and occurs throughout the warmer regions of the world. It is best represented in the Americas; about 65 species occur in continental Africa and about 125 in Madagascar.

Growth and development

In Central Africa Croton sylvaticus flowers from October–December and fruits from January–May. The seeds are dispersed by birds, which feed on the fruits.

Ecology

Croton sylvaticus occurs in semi-deciduous savanna, secondary forest and mixed evergreen forest, often on rocky slopes, in river gully forest and on rocky outcrops, from sea-level up to 1700 m altitude. In Uganda it often occurs in old Eucalyptus plantations. It prefers light to deep shade, but survives in full sun.

Propagation and planting

Croton sylvaticus is propagated by seed or wildlings. The fruits are collected before they open and placed in the sun to dry and open, after which the seeds are collected. The seeds need to be stored cool and dry. They are sown in containers in a mixture of river sand and compost (1:2), lightly covered with compost and kept moist. Germination occurs after 2–3 weeks. The seedlings are transplanted at the 2-leaf stage, either in the field or in plastic bags filled with river sand and compost (1:1).

Management

Croton sylvaticus is fast growing, and does not need particular care.

Harvesting

The bark, leaves and roots can be harvested whenever the need arises. Fruits can be harvested during 5–6 months per year.

Handling after harvest

The plant parts harvested are used fresh or dried and stored in a dry, cool place for later use.

Genetic resources

Croton sylvaticus is relatively common in many parts of tropical Africa, except in West Africa, where it is quite rare. It grows in several types of vegetation and is therefore not likely to be threatened by genetic erosion, except in localities where it has been overharvested.

Prospects

Croton sylvaticus has a wide range of local medicinal uses, especially its bark. Several laboratory tests showed toxicity but also pharmacological activity, and more research is needed to identify the active compounds in order to evaluate its effective and safe use.

Major references

• Elgorashi, E.E., Taylor, J.L.S., Maes, A., de Kimpe, N., van Staden, J. & Verschaeve, L., 2002. The use of plants in traditional medicine: potential genotoxic risks. South African Journal of Botany 68(3): 408–410.

• Frum, Y. & Viljoen, A.M., 2006. In vitro 5-lipoxygenase and anti-oxidant activities of South African medicinal plants commonly used topically for skin diseases. Skin Pharmacology and Physiology 19: 329–335.

• Grace, O.M., Prendergast, H.D.V., Jäger, A.K. & van Staden, J., 2002. Bark medicines in traditional healthcare in KwaZulu-Natal, South Africa: an inventory. South African Journal of Botany 69(3): 301–363.

• Kapingu, M., Mbwambo, Z., Moshi, M.J. & Magadula, J., 2005. Brine shrimp lethality of a glutarimide alkaloid from Croton sylvaticus Hochst. The East and Central African Journal of Pharmaceutical Sciences 8(1): 3–5.

• Katende, A.B., Birnie, A. & Tengnäs, B., 1995. Useful trees and shrubs for Uganda: identification, propagation and management for agricultural and pastoral communities. Technical Handbook 10. Regional Soil Conservation Unit, Nairobi, Kenya. 710 pp.

• Kokwaro, J.O., 1993. Medicinal plants of East Africa. 2nd Edition. Kenya Literature Bureau, Nairobi, Kenya. 401 pp.

• Latham, P., 2004. Useful plants of Bas-Congo province, Democratic Republic of the Congo. DFID, London, United Kingdom. 320 pp.

• Baerts, M. & Lehmann, J., 2006. Croton sylvaticus. [Internet]. Prelude Medicinal Plants Database. Metafro-Infosys, Royal Museum for Central Africa, Tervuren, Belgium http://www.metafro.be/prelude. January 2007.

• Moshi, M.J., Cosam, J.C., Mbwambo, Z.H., Kapingu, M. & Nkunya, M.H.H., 2004. Testing beyond ethnomedical claims: brine shrimp lethality of some Tanzanian plants. Pharmaceutical Biology 42(7): 547–551.

• Radcliffe-Smith, A., 1996. Euphorbiaceae, subfamilies Phyllantoideae, Oldfieldioideae, Acalyphoideae, Crotonoideae and Euphorbioideae, tribe Hippomaneae. In: Pope, G.V. (Editor). Flora Zambesiaca. Volume 9, part 4. Royal Botanic Gardens, Kew, Richmond, United Kingdom. pp. 1–337.

Other references

• Beentje, H.J., 1994. Kenya trees, shrubs and lianas. National Museums of Kenya, Nairobi, Kenya. 722 pp.

• 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.

• Coates Palgrave, K., 1983. Trees of southern Africa. 2nd Edition. Struik Publishers, Cape Town, South Africa. 959 pp.

• Grace, O.M., Prendergast, H.D.V., Jäger, A.K. & Van Staden, J., 2003. The suitability of thin layer chromatography for authenticating bark medicines used in South African traditional healthcare. South African Journal of Botany 69(2): 1–5.

• Léonard, J., 1962. Euphorbiaceae. In: Robyns, W., Staner, P., Demaret, F., Germain, R., Gilbert, G., Hauman, L., Homès, M., Jurion, F., Lebrun, J., Vanden Abeele, M. & Boutique, R. (Editors). Flore du Congo belge et du Ruanda-Urundi. Spermatophytes. Volume 8, 1. Institut National pour l’Étude Agronomique du Congo belge, Brussels, Belgium. 214 pp.

• Lovett, J.C., Ruffo, C.K., Gereau, R.E. & Taplin, J.R.D., 2006. Field guide to the moist forest trees of Tanzania. [Internet] Centre for Ecology Law and Policy, Environment Department, University of York, York, United Kingdom. http://www.york.ac.uk/ res/celp/webpages/projects/ecology/ tree%20guide/guide.htm. January 2007.

• Raponda-Walker, A. & Sillans, R., 1961. Les plantes utiles du Gabon. Paul Lechevalier, Paris, France. 614 pp.

• Vieux, A.S. & Kabele Ngiefu, C., 1970. Etude de quelques espèces oléagineuses de la République Démocratique du Congo. Oléagineux 25: 395–399.

Sources of illustration

• Léonard, J., 1962. Euphorbiaceae. In: Robyns, W., Staner, P., Demaret, F., Germain, R., Gilbert, G., Hauman, L., Homès, M., Jurion, F., Lebrun, J., Vanden Abeele, M. & Boutique, R. (Editors). Flore du Congo belge et du Ruanda-Urundi. Spermatophytes. Volume 8, 1. Institut National pour l’Étude Agronomique du Congo belge, Brussels, Belgium. 214 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., 2007. Croton sylvaticus Hochst. ex C.Krauss. In: Schmelzer, G.H. & Gurib-Fakim, A. (Editors). PROTA (Plant Resources of Tropical Africa / Ressources végétales de l’Afrique tropicale), Wageningen, Netherlands. Accessed 17 December 2024.

• See the Prota4U database.