Combretum collinum (PROTA)

Plant Resources of Tropical Africa Introduction

List of species

General importance
Geographic coverage Africa
Geographic coverage World
Carbohydrate / starch
Essential oil / exudate
Medicinal
Timber
Fuel
Ornamental
Forage / feed
Auxiliary plant
Climate change

Combretum collinum Fresen.

distribution in Africa (wild)

1, inflorescence and leaf; 2, flower in longitudinal section; 3, fruit. Redrawn and adapted by Achmad Satiri Nurhaman

Protologue: Mus. Senckenberg. 2: 153 (1837).

Family: Combretaceae

Chromosome number: 26

Synonyms

• Combretum binderanum Kotschy (1865),
• Combretum geitonophyllum Diels (1907),
• Combretum hypopilinum Diels (1907),
• Combretum lamprocarpum Diels (1907).

Vernacular names

• Variable bush-willow, variable combretum (En).
• Mlama (Sw).

Origin and geographic distribution

Combretum collinum is widespread in the dry savanna of tropical Africa, and occurs from Senegal to East Africa and south throughout southern Africa to north-eastern South Africa.

Uses

Combretum collinum has a large number of uses in Africa, and especially in traditional medicine. A fresh or dried leaf infusion and root decoction is widely taken as a cholagogue, diuretic and purgative and also to treat gastro-intestinal problems, including diarrhoea, dysentery, stomach-ache and ascariasis. A leaf and leafy twig decoction is drunk and fresh roots are chewed to treat lung problems including coughs, bronchitis and tuberculosis and also to treat snakebites and jaundice. The juice from the roots is further externally applied to snakebite wounds, syphilitic sores and toothache. A root maceration or decoction is taken to treat gonorrhoea, female sterility and pyomyositis. A root decoction, together with roots and bark of Kigelia africana (Lam.) Benth., is taken for the treatment of excessive menstrual bleeding beyond the normal time. Furthermore, a root infusion is given to delivering women to enhance labour and to epileptic patients. Root powder in petroleum jelly is applied topically in the treatment of epilepsy. Bark powder is eaten in porridge to treat rectal prolapse and haemorrhoids. A twig bark and root decoction is drunk to treat pain in the side and headache. Leaf sap is applied to wounds, ulcers and leprosy and also used as ear drops to treat earache. Crushed leaves are applied as poultice and used for bathing to treat fatigue and rheumatism. A leaf and root infusion is taken as a blood tonic.

Leaves, stem bark and roots are often used alone or in mixtures with other plants to treat fever, malaria and appendicitis. The gum exuded from injured branches is edible and used to cure toothache or to plug a tooth with caries. Seed powder is applied to eye infections in cattle.

The wood of Combretum collinum is fairly hard and durable and rather termite resistant but prone to rot in the ground. It is popular for fencing poles, canoes and tool handles and has been used for wagon building. The wood is a good source of firewood and makes very good charcoal. Combretum collinum can be planted as an ornamental for shade or shelter. It can be planted as a firebreak, as the tree is tolerant of grass fires. Flowers produce good nectar for honey. The leaves are widely browsed by sheep, goats and cattle, although in some regions cattle does not like it.

In Nigeria unidentified parts have been used as famine food. The roots provide a fiber used in basket work. In Uganda the wood is used for fermenting local beer. In South Africa, the winged fruits can be strung together to make attractive room-dividers or spray-painted as Christmas decorations.

Production and international trade

Parts of Combretum collinum are sold at local markets for medicinal use. In South Africa the winged fruits are locally commercialized for ornamental purposes.

Properties

Few phytochemical and pharmacological analyses have been done on Combretum collinum. The stilbenoids combretastatins A and B and several phenanthrenes have been isolated from the aerial parts. The triterpenoid components of the leaves and fruits of 3 southern African subspecies of Combretum collinum yielded varying amounts of 4 cycloartane acids. None of these compounds appeared to be responsible for the toxic properties of the fruits. From the gum exudate a range of amino acids has been isolated, with aspartic acid, glycine, glutamic acid and alanine as the most important ones.

The crude extract and ethanol extract of fresh shoot bark showed significant and dose-dependent larvicidal activity on fourth instar larvae of the yellow fever mosquito, Aedes aegypti. Different leaf extracts were found to have weak antifungal and anthelmintic activities in vitro. An aqueous root and stem bark extract showed antibacterial activity against Proteus mirabilis.

Combretum collinum has whitish-brown sapwood, which is not clearly differentiated from the pale brown heartwood. The wood has an interlocked grain and a course texture.

Description

Shrub or small to medium-sized, multi-stemmed, deciduous tree up to 12(–17) m tall, with a heavy, rounded or flat crown; bark pale grey, creamy-brown, reddish-brown or brown-black, fissured, transversely cracked, with smooth scales of various sizes; young shoots densely covered with short, soft hairs. Leaves opposite, alternate or in whorls of 3, very variable, simple and entire; stipules absent; petiole 1–3(–4) cm long; blade narrowly elliptical to broadly ovate or obovate, 6–18(–22) cm × 3–8 cm, apex attenuate, base broadly cuneate, almost glabrous above, dark green, reddish olive to yellowish brown when dry, glabrous to densely woolly-hairy below, pale green to silvery, conspicuously scaly, pinnately veined with (6–)8–16(–20) pairs of lateral veins. Inflorescence an axillary or supra-axillary spike or panicle up to 10 cm long, rachis glabrous to woolly hairy. Flowers bisexual, 4-merous, regular, cream to yellow, up to 5 mm in diameter, sweetly scented, sessile; receptacle consisting of 2 parts, lower part 2–4 mm long, glabrous or hairy, scaly, upper part c. 3.5 mm × 2.5 mm, campanulate at base, cup-shaped at apex, glabrous to hairy, scaly; sepals broadly triangular, c. 1 mm long; petals free, transversely elliptical to obovate or circular, apex notched, clawed; stamens 8, 4.5–6.5 mm long; ovary inferior, 1-celled, style up to 7.5 mm long. Fruit a 4-winged nut, variable in shape, 2.5–6 cm long, stipe up to 2 cm long, wings variable in width, rusty red when young, becoming dark chocolate brown or deep golden brown when mature, with a metallic sheen caused by the scales, indehiscent, 1-seeded. Seedling with hypogeal germination.

Other botanical information

Combretum is a very large genus, comprising about 250 species and distributed worldwide in the tropics and subtropics. About 140 species occur in tropical Africa; c. 20 species are endemic to Madagascar.

Combretum collinum is a highly variable species and at least 11 subspecies have been distinguished, differing from each other only in minor characters.

Growth and development

In West Africa it flowers during the second half of the dry season or the beginning of the rainy season. In southern Africa it flowers in August to October with the previous season’s leaves still present and fruiting occurs from January to August. Old fruits may be found on the tree for most of the year. Fruiting can be sparse or prodigious.

Ecology

Combretum collinum occurs in arid, semi-arid and tree savanna, as well as in deciduous and evergreen thickets and on termite mounds, from sea-level up to 2200 m altitude.

It grows in a variety of soils, in semi-arid to medium rainfall conditions. It is drought and frost tolerant when mature.

Propagation and planting

Combretum collinum is propagated by seedlings and wildlings. Seeds storage behaviour is orthodox. The seeds retain their viability for several months if kept dry and free from insects, at a maximum temperature of 20ºC. For best germination, pre-sowing treatments such as fruit scarification or soaking should be done. The pretreated fruits do not store well and should be sown immediately. Seeds can also be extracted from the fruit, but removal of the seed is not easy, and soaking of the fruit in cold water before opening facilitates the process. The seeds should be soaked for a few hours in water before being sown in a mixture of river sand and compost. Seedlings may appear after 8–20(–35) days, and the germination rate varies from 0 to 90%. After 5–6 weeks the first leaves appear, and the seedlings are vulnerable to fungal attack in humid conditions; 55–80% survives the seedling stage. The seedlings can be transplanted into growing containers once they reach the 2-leaf stage. Growth is rapid, at least 50 cm per year. Natural germination is hampered by bush fires and dry spells.

Management

Combretum collinum can be pollarded, coppiced, trimmed and pruned. Young plants are vulnerable to cold wind and frost. In cultivation, it prefers a humus-rich soil and partial shade. Over-watering results in poor flowering.

Combretum collinum has a higher incidence of coppicing than other Combretum spp. because of its good fuel wood properties. It sprouts quickly after cutting and fire.

Diseases and pests

The larvae of the bark borer moths Salagena obsolescens and Salagena transversa feed on Combretum collinum, and the larvae may kill branches or sometimes even the whole tree. The seeds of Combretum collinum are often parasitized.

Harvesting

The leaves, stems, bark and roots of Combretum collinum are harvested from the wild or from home gardens, whenever the need arises. Removal of the bark should be done in small pieces and not by ring barking, as is commonly done. Harvesting the roots is even more destructive.

Handling after harvest

The harvested bark, leaves, stems and roots are washed and air-dried before use or trade. For long-term storage (up to 6 months), the plant parts are sun-dried and stored in airtight containers. A decoction of the leaves, root, stem or bark can be stored in bottles to be used within a week. If refrigerated, it can be stored for much longer.

Genetic resources

Combretum collinum is widespread in most of its area of distribution and is not in danger of genetic erosion. In regions where population pressure is high, it is overexploited for firewood and is frequently cut down on agricultural land. In Uganda and South Africa excessive cutting of Combretum collinum has been reported and this calls for measures to protect some of its natural stands. Combretum collinum subsp. suluense (Engl. & Diels) Okafor is listed as ‘low risk but least concern’ on the IUCN Red List in KwaZulu-Natal and neighboring regions of South Africa. However, no systematic germplasm collections exist; however, there are small collections in botanical gardens, private gardens and research institutions in Kenya, Uganda, Tanzania, Zimbabwe and South Africa.

Prospects

Combretum collinum is widespread and commonly used in traditional medicine. In view of these uses, surprisingly few phytochemical and pharmacological analyses have been carried out, and further research to identify bioactive compounds need to be carried out to corroborate the medicinal properties. Research on propagation and domestication as well as quality control and measures for sustainable utilization are needed.

Major references

• Adamu, H.M., Abayeh, O.J., Agho, M.O., Abdullahi, A.L., Uba, A., Dukku, H.U. & Wufem, B.M., 2005. An ethnobotanical survey of Bauchi State herbal plants and their antimicrobial activity. Journal of Ethnopharmacology 99(1): 1–4.
• Baerts, M. & Lehmann, J., 2011. Combretum collinum. [Internet] Prelude Medicinal Plants Database. Metafro-Infosys, Royal Museum for Central Africa, Tervuren, Belgium http://www.metafro.be/prelude. Accessed April 2011.
• 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.
• Eloff, J.N., Katerere, D.R. & McGaw, L.J., 2008. The biological activity and chemistry of the southern African Combretaceae. Journal of Ethnopharmacology 119: 686–699.
• Exell, A.W., 1978. Combretaceae. In: Launert, E. (Editor). Flora Zambesiaca. Volume 4. Flora Zambesiaca Managing Committee, London, United Kingdom. pp. 100–183.
• Katerere, D.R.P., 2001. Phytochemical and pharmacological studies of African Combretaceae. PhD Thesis. University of Strathclyde, Glasgow, United Kingdom.
• Neuwinger, H.D., 2000. African traditional medicine: a dictionary of plant use and applications. Medpharm Scientific, Stuttgart, Germany. 589 pp.
• Palmer, E. & Pitman, N., 1972–1974. Trees of southern Africa, covering all known indigenous species in the Republic of South Africa, South-West Africa, Botswana, Lesotho and Swaziland. 3 volumes. Balkema, Cape Town, South Africa. 2235 pp.
• Watt, J.M. & Breyer-Brandwijk, M.G., 1962. The medicinal and poisonous plants of southern and eastern Africa. 2nd Edition. E. and S. Livingstone, London, United Kingdom. 1457 pp.
• Wickens, G.E., 1973. Combretaceae. In: Polhill, R.M. (Editor). Flora of Tropical East Africa. Crown Agents for Oversea Governments and Administrations, London, United Kingdom. 99 pp.

Other references

• Abreu, P.M., Martins, E.S., Kayser, O., Bindseil, K.-U., Siems, K., Seemann, A. & Frevert, J., 1999. Antimicrobial, antitumor and antileishmania screening of medicinal plants from Guinea-Bissau. Phytomedicine 6(3): 187–195.
• Adjanohoun, E.J., Adjakidjè, V., Ahyi, M.R.A., Aké Assi, L., Akoègninou, A., d’Almeida, J., Apovo, F., Boukef, K., Chadare, M., Cusset, G., Dramane, K., Eyme, J., Gassita, J.N., Gbaguidi, N., Goudote, E., Guinko, S., Houngnon, P., Lo, I., Keita, A., Kiniffo, H.V., Kone-Bamba, D., Musampa Nseyya, A., Saadou, M., Sodogandji, T., De Souza, S., Tchabi, A., Zinsou Dossa, C. & Zohoun, T., 1989. Contribution aux études ethnobotaniques et floristiques en République Populaire du Bénin. Agence de Coopération Culturelle et Technique, Paris, France. 895 pp.
• Anderson, D.M.W., Howlett, J.F. & McNab, C.G.A., 1987. Amino acid composition of gum exudates from some African Combretum, Terminalia and Anogeissus species. Phytochemistry 26(3): 837–839.
• Arbonnier, M., 2004. Trees, shrubs and lianas of West African dry zones. CIRAD, Margraf Publishers Gmbh, MNHN, Paris, France. 573 pp.
• Coates Palgrave, K., 2002. Trees of southern Africa. 3rd Edition. Struik Publishers, Cape Town, South Africa. 1212 pp.
• Eloff, J.N., 1999. The antibacterial activity of 27 southern African members of the Combretaceae. South African Journal of Science 95: 148–152.
• Fyhrquist, P., Mwasumbi, L., Haeggstrom, C.A., Vuorela, H., Hitunen, R. & Vuorela, P., 2004. Antifungal activity of selected species of Terminalia, Pteleopsis and Combretum (Combretaceae) collected in Tanzania. Pharmaceutical Biology 42(4/5): 308–317.
• Fyhrquist, P., Mwasumbi, L., Vuorela, P., Vuorela, H., Hitunen, R., Murphy, C. & Adlercreutz, H., 2006. Preliminary antiproliferative effects of some species of Terminalia, Combretum and Pteleopsis collected in Tanzania on some human cancer cell lines. Fitoterapia 77(5): 358–366.
• 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.
• Leyens, T. & Lobin, W., 2009. Manual de plantas úteis de Angola. Bischöfliches Hilfswerk Misereor, Aachen, Germany. 181 pp.
• Masoko, P. & Eloff, J.N., 2006. Bioautography indicates the multiplicity of antifungal compounds from twenty-four southern African Combretum species (Combretaceae). African Journal of Biotechnology 5(18): 1625–1647.
• Masoko, P. & Eloff, J.N., 2007. Screening of twenty-four South African Combretum and six Terminalia species (Combretaceae) for antioxidant activities. The African Journal of Traditional, Complementary and Alternative Medicine 4(2): 231–239.
• McGaw, L.J., Rabe, T., Sparg, S.G., Jäger, A.K., Eloff, J.N. & van Staden, J., 2001. An investigation on the biological activity of Combretum species. Journal of Ethnopharmacology 75: 45–50.
• Odda, J., Kristensen, S., Kabasa J. & Waako, P., 2008. Larvicidal activity of Combretum collinum Fresen against Aedes aegypti. Journal of Vector Borne Diseases 45(4): 321–324.
• Panzini, I., Pelizzoni, F., Verotta, L. & Rogers, C.B., 1992. The search for the "hiccup nut" toxin: a chemical investigation of Combretum fruit. Planta Medica 58(7): A711–A712.
• Rogers, C.B. & Coombes, P.H., 1999. Acidic triterpene glycosides in trichome secretions differentiate subspecies of Combretum collinum in South Africa. Biochemical. Systematics and Ecology 27: 321–323.
• SEPASAL, 2011. Combretum collinum. [Internet] Survey of Economic Plants for Arid and Semi-Arid Lands (SEPASAL) database. Royal Botanic Gardens, Kew, Richmond, United Kingdom. http://www.kew.org/ ceb/sepasal/. Accessed April 2011.

Sources of illustration

• Engler, A., 1899. Monographien Afrikanischer Pflanzen-Familien und - Gattungen. 3. Combretaceae - Combretum. Wilhelm Engelmann, Leipzig, Germany. 116 pp. + 30 tables.

Author(s)

• A. Maroyi, Department of Biodiversity, School of Molecular and Life Sciences, University of Limpopo, Private Bag X 1106, Sovenga 0727, South Africa

Correct citation of this article

Maroyi, A., 2012. Combretum collinum Fresen. In: Schmelzer, G.H. & Gurib-Fakim, A. (Editors). Prota 11(2): Medicinal plants/Plantes médicinales 2. PROTA, Wageningen, Netherlands. Accessed 22 December 2024.

• See this page on the Prota4U database.