Nuxia congesta (PROTA)

Plant Resources of Tropical Africa Introduction

List of species

Nuxia congesta R.Br. ex Fresen.

Protologue: Flora 21: 606 (1838).

Family: Loganiaceae (APG: Stilbaceae)

Synonyms

Lachnopylis sambesina (Gilg) C.A.Sm.

Vernacular names

Common wild elder, brittle wood (En).

Origin and geographic distribution

Nuxia congesta is the most widespread species of the genus, occurring from Guinea eastward to Ethiopia and Somalia and southward through East Africa to South Africa and Swaziland. It is also found in southern Arabia.

Uses

The wood of Nuxia congesta is mainly used for poles for construction, fence posts and carpentry. It is suitable for furniture. It is also used as firewood and for charcoal production, whereas branches are used as firesticks. The abundance of fragrant flowers makes Nuxia congesta an attractive ornamental. It is suitable as boundary, barrier and support tree. The trees prevent erosion on rocky sites and provide shade or shelter. The foliage is browsed by livestock. In traditional medicine in Kenya, bark decoctions are taken to treat indigestion and menstrual problems, and as an expectorant. Bark and leaves are also chewed against indigestion, whereas ash of leafy twigs is taken in water against diarrhoea. In Uganda the bark is applied against toothache and impotence. Smoke from the leaves is applied to the udder to treat mastitis in cattle. In Kenya and Tanzania Nuxia congesta is an important honey plant.

Properties

The heartwood is white to whitish yellow and indistinctly demarcated from the sapwood. The texture is fine and even. The wood is medium-weight to fairly heavy, with a density of 650–860 kg/m³ at 12% moisture content, and moderately hard. It has a severe risk of surface checking and end splitting during air drying. At 12% moisture content, the modulus of rupture is 71 N/mm² and compression parallel to grain 53 N/mm². The wood is not durable.

Description

Evergreen shrub or small tree up to 15(–25) m tall; bole often gnarled and fluted, up to 60(–100) cm in diameter; bark surface fissured, peeling in narrow strips or scales, grey to brown, inner bark yellowish white; twigs short-hairy to glabrous, often orange. Leaves arranged in whorls of 3(–4) at the ends of branches, simple; stipules absent; petiole up to 2 cm long; blade elliptical to obovate or nearly orbicular, (1–)2–15 cm × (0.5–)1–7.5 cm, base cuneate, apex rounded to acute or short-acuminate, entire or sometimes toothed, leathery, glabrous or slightly short-hairy, pinnately veined with up to 10 pairs of lateral veins. Inflorescence a terminal or axillary, often umbel-like panicle up to 15 cm × 15 cm, short-hairy. Flowers bisexual, nearly regular, 4-merous, fragrant, nearly sessile; calyx tubular, 3–8 mm long, with short lobes; corolla whitish, tube usually slightly shorter than calyx, lobes 2–5 mm long, hairy in the throat of the tube; stamens inserted at apex of corolla tube, alternating with lobes, up to 8 mm long; ovary superior, ovoid to ellipsoid, 1.5–2.5 mm long, hairy, 2-celled, style slender, up to 11 mm long. Fruit an ovoid to ellipsoid capsule slightly longer than the persistent calyx, hairy, dehiscing with 2–4 valves, many-seeded. Seeds spindle-shaped, c. 2 mm long, brown.

Other botanical information

Nuxia congesta frequently develops suckers when it is subject to regular fires. The flowers produce abundantly nectar and pollen and are commonly visited by bees, which are probably the main pollinators.

Nuxia comprises about 15 species occurring in southern Arabia and throughout tropical Africa, including Comoros, Madagascar and the Mascarene Islands.

Ecology

Nuxia congesta is a pioneer in evergreen forest, wooded savanna and grassland, usually in mountain regions up to 3200 m altitude, but in South Africa also occurring near sea-level. It is often found growing on edges of open, upland or lower montane forest, often associated with bamboo, Juniperus procera Hochst. ex Endl. or Olea europaea L. It may be common on rocky ridges.

Management

Direct seeding is the most reliable method of propagation. Mature fruits should be collected and seeds can be obtained by threshing. The seeds can be stored in a dry and cool locality for some time. Nuxia congesta is suitable for planting in marginal areas and on rocky soils. It can be coppiced.

Genetic resources

Nuxia congesta is very widespread and common in many regions, and not in danger of genetic erosion.

Prospects

The wood of Nuxia congesta is likely to remain an important source of poles for construction and fencing, but its suitability as a general-purpose timber warrants testing. However, the usually small size and poor shape of the bole is a major drawback. The many uses in traditional medicine need to be investigated.

Major references

• Chikamai, B.N., Githiomi, J.K., Gachathi, F.N. & Njenga, M.G., undated. Commercial timber resources of Kenya. Kenya Forestry Research Institute (KEFRI), Nairobi, Kenya. 164 pp.

• Coates Palgrave, K., 2002. Trees of southern Africa. 3rd Edition. Struik Publishers, Cape Town, South Africa. 1212 pp.

• Leeuwenberg, A.J.M., 1975. The Loganiaceae of Africa. 14. A revision of Nuxia. Mededelingen Landbouwhogeschool Wageningen 75–8. Wageningen, the Netherlands. 80 pp.

• Maundu, P. & Tengnäs, B. (Editors), 2005. Useful trees and shrubs for Kenya. World Agroforestry Centre - East and Central Africa Regional Programme (ICRAF-ECA), Technical Handbook 35, Nairobi, Kenya. 484 pp.

• Orwa, C., Mutua, A., Kindt, R., Jamnadass, R. & Simons, A., 2009. Agroforestree database: a tree reference and selection guide. Version 4.0. [Internet] World Agroforestry Centre (ICRAF), Nairobi, Kenya. http://www.worldagroforestry.org/ resources/databases/ agroforestree. December 2011.

Other references

• Bekele-Tesemma, A., 2007. Useful trees and shrubs for Ethiopia: identification, propagation and management for 17 agroclimatic zones. Technical Manual No 6. RELMA in ICRAF Project, Nairobi, Kenya. 552 pp.

• Bruce, E.A. & Lewis, J., 1960. Loganiaceae. In: Hubbard, C.E. & Milne-Redhead, E. (Editors). Flora of Tropical East Africa. Crown Agents for Oversea Governments and Administrations, London, United Kingdom. 47 pp.

• Burkill, H.M., 1995. The useful plants of West Tropical Africa. 2nd Edition. Volume 3, Families J–L. Royal Botanic Gardens, Kew, Richmond, United Kingdom. 857 pp.

• Friis, I., 1992. Forests and forest trees of northeast tropical Africa: their natural habitats and distribution patterns in Ethiopia, Djibouti and Somalia. Kew Bulletin, Additional Series 15, H.M.S.O., London, United Kingdom. 396 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.

• Latham, P., 2007. Plants visited by bees and other useful plants of Umalila, southern Tanzania. Third edition. P.Latham, DFID, United Kingdom. 216 pp.

• Leeuwenberg, A.J.M., 1983. Loganiaceae. In: Launert, E. (Editor). Flora Zambesiaca. Volume 7, part 1. Flora Zambesiaca Managing Committee, London, United Kingdom. pp. 327–374.

• Lovett, J.C., Ruffo, C.K., Gereau, R.E. & Taplin, J.R.D., 2007. Nuxia floribunda. 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://celp.org.uk/ webpages/projects/ecology/tree%20guide/pages/LOGANIACEAE/ Nuxia%20floribunda.htm. December 2011.

• Mothogoane, M.S., 2011. Nuxia congesta. [Internet] South African National Biodiversity Institute, Pretoria, South Africa. http://www.plantzafrica.com/ plantnop/ nuxiacongesta.htm. December 2011

• Neuwinger, H.D., 2000. African traditional medicine: a dictionary of plant use and applications. Medpharm Scientific, Stuttgart, Germany. 589 pp.

Author(s)

• L.P.A. Oyen, PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands

Correct citation of this article

Oyen, L.P.A., 2012. Nuxia congesta R.Br. ex Fresen. In: Lemmens, R.H.M.J., Louppe, D. & Oteng-Amoako, A.A. (Editors). PROTA (Plant Resources of Tropical Africa / Ressources végétales de l’Afrique tropicale), Wageningen, Netherlands. Accessed 22 April 2026.

• See the Prota4U database.