Boscia salicifolia (PROTA)

Plant Resources of Tropical Africa Introduction

List of species

General importance
Geographic coverage Africa
Geographic coverage World
Fruit
Vegetable
Carbohydrate / starch
Medicinal
Timber
Fuel
Ornamental
Forage / feed
Auxiliary plant
Food security
Climate change

distribution in Africa (wild)

Boscia salicifolia Oliv.

1, tree habit; 2, flowering twig; 3, flower; 4, fruits. Redrawn and adapted by J.M. de Vries

Protologue: Fl. trop. Afr. 1: 93 (1868).

Family: Capparaceae

Vernacular names

• Willow-leaved boscia (En).

Origin and geographic distribution

Boscia salicifolia is very widespread and occurs from Mauritania, Senegal and Gambia eastward to Somalia and southward to Botswana, Zimbabwe and Mozambique. It is also found in southern Egypt.

Uses

Bark decoctions or infusions are taken as aphrodisiac and applied externally to treat conjunctivitis. Root decoctions are taken to treat diarrhoea, inflammations, oedema and psychiatric disorders, and as aphrodisiac. Powdered leaves are administered in milk or gruel as galactagogue and to treat skin complaints. Throughout its distribution area pounded leaves are applied to wounds, abscesses, furuncles, swollen glands, haemorrhoids and itching skin, and as anodyne. Leaf ash is taken as antidote for poisoning and to treat tuberculosis. Pounded leaves in water are added to food of livestock to treat diarrhoea.

The bark and leaves are added to soup, particularly in times of food shortage. In southern Africa roasted roots are occasionally eaten, but have also been said to be toxic. In Niger the roots have been used as an ingredient in the preparation of arrow poison. Seeds are eaten after cooking. The foliage is browsed by livestock. The wood is used for building poles and as firewood. The tree provides shade for livestock, and is occasionally planted as roadside tree.

Production and international trade

Dried leaves and bark are occasionally found in local markets.

Properties

Several glycosides of the flavonols rhamnocitrin and rhamnetin have been isolated from the leaves, as well as the triterpene lupeol and some sterols such as stigmasterol and β-sitosterol. The β-ionone derivative (–)-boscialin has also been isolated from the leaves. This compound showed some activity against various microbes and against Trypanosoma brucei, and showed cytotoxicity against human cancer cell lines. Bark and leaf extracts showed antibacterial activity against Staphylococcus aureus and Escherichia coli, as well as antifungal activity. Aqueous and methanol extracts of the bark showed pronounced in-vitro antiplasmodial activity against both chloroquine-sensitive and chloroquine-resistant Plasmodium falciparum strains. Methanol extracts significantly prolonged the survival time of mice infected with Plasmodium berghei. Aqueous extracts had little effect, but when used in combinations with water extracts of other medicinal plants used to treat malaria (Lannea schweinfurthii (Engl.) Engl., Sclerocarya birrea (A.Rich.) Hochst. and Searsia natalensis (Bernh. ex Krauss) F.A.Barkley) they exhibited high suppression of the malaria parasite in vivo. In tests, dried powdered bark burnt on glowing charcoal killed all yellow fever mosquitoes (Aedes aegypti) within 20 minutes.

The bark of Boscia salicifolia tastes sweet. In a test, the yield of sugars was 10.1%, consisting of 100% sucrose. Boscia salicifolia is considered a valuable forage species in the Sahel region, with a crude protein content of about 20%.

Description

Usually deciduous shrub or small tree up to 12(–15) m tall; bole often short but massive, often twisted; bark surface rough, becoming scaly to cracked, silver-grey to dark grey, inner bark yellow; crown rounded but often flattened, often with drooping branches; twigs finely hairy, soon becoming glabrous. Leaves alternate, simple and entire; stipules absent or soon falling; petiole 8–15 mm long, usually short-hairy; blade narrowly ovate or narrowly elliptical to linear, (4.5–)7–15(–17.5) cm × 1–2(–3.5) cm, cuneate at base, acute at apex, thin-leathery, glabrous or finely hairy below, pinnately veined with indistinct veins.

Inflorescence an axillary or terminal raceme up to 10 cm long, short-hairy, many-flowered. Flowers bisexual, regular, greenish yellow; pedicel 0.5–1 cm long; sepals 4(–5), free, ovate-oblong, 3–4.5 mm long, hairy; petals absent, but receptacle with fringed disk; stamens 14–22, free, 5–9 mm long; ovary superior, stalked, ovoid, glabrous, 1-celled, style very short but thick, stigma prominent, flattened. Fruit a globose berry 1–2 cm in diameter, slightly pitted, orange-yellow, 1–3-seeded. Seeds globose, c. 1 cm in diameter, rough, brown.

Other botanical information

Boscia comprises about 20 species and mainly occurs in semi-arid regions of mainland Africa, Madagascar and Arabia. Several other Boscia spp. are used in traditional medicine in tropical Africa.

Boscia senegalensis (Pers.) Lam. ex Poir. occurs in similar habitats as Boscia salicifolia, from Mauritania and Senegal east to Eritrea and Ethiopia. It is an important medicinal plant, but even more important for its edible fruits. Boscia albitrunca (Burch.) Gilg & Benedict and Boscia coriacea Pax are other species of which the edible fruits are more important than their medicinal uses.

Boscia foetida Schinz is a spiny shrub or small tree up to 5 m tall, occurring in dry woodland in Namibia, Botswana, Zimbabwe, Mozambique and South Africa. Decoctions of leafy twigs are applied to treat earache and eye complaints. Leaf decoctions are taken to promote menstruation and as anodyne. Pounded and cooked roots are eaten as porridge. Root powder has been used as coffee substitute. The fruits are edible.

Boscia mossambicensis Klotsch is a shrub or small tree up to 8 m tall, widespread from southern Ethiopia and Somalia southward to northern South Africa. In southern Ethiopia it is used for cleansing implements used during milking and it is browsed by livestock, whereas its wood is used in house construction and as firewood.

Boscia longifolia Hadj-Moust. is a shrub or small tree up to 10 m tall occurring in dry forest in southern Madagascar. In Madagascar a root decoction is taken to treat fever and dizziness, and to stimulate appetite. Decoctions of the aerial parts of the plant are also taken against fever, and leaf infusions against rheumatism.

Boscia madagascariensis (DC.) Hadj-Moust. is a shrub or small tree up to 10 m tall, characterized by leaves with 3 leaflets and widespread in dry forest of western Madagascar. Bark and leaves are reputed to be aphrodisiac and tonic.

Boscia plantefolii Hadj-Moust. is a shrub or small tree up to 10 m tall occurring in dry forest in northern and western Madagascar. It is reputed for its stimulant, tonic and aphrodisiac properties.

Growth and development

In West Africa Boscia salicifolia flowers during the first part of the dry season. The flowers are pollinated by insects, which are attracted by the copious nectar. The fruits are eaten by birds, which serve as seed dispersers.

Ecology

Boscia salicifolia occurs in deciduous woodland and wooded grassland, up to 2100 m altitude. It is often found on stony or rocky soils, but also on sandy soils. It is locally common on termite mounds. Boscia salicifolia is very drought resistant; it grows in dry regions with 200–400 mm annual rainfall.

Propagation and planting

There are 4000–5000 seeds per kg. The germination rate of seeds is generally high even without pre-treatment, and seeds germinate rapidly. However, they should be sown soon after collecting.

Management

The trees can be coppiced well, with about 80% of the stumps resprouting.

Genetic resources

Boscia salicifolia has a very large distribution area, and therefore it is not threatened by genetic erosion. However, it is not common in most regions.

Prospects

Some uses of Boscia salicifolia in traditional medicine have been supported by the results of pharmacological investigations, particularly relating to antibacterial properties. Bark extracts showed interesting antimalarial activity, but thorough toxicological studies are still needed before they can be developed into new medicines. The bark could be used as basis for the production of mosquitocides.

Several parts of the plant are edible and play an important role in times of food scarcity for humans as well as animals in the drier parts of Africa. This multipurpose species is worth of protection, and should be taken up into planting programmes.

Major references

• Arbonnier, M., 2004. Trees, shrubs and lianas of West African dry zones. CIRAD, Margraf Publishers Gmbh, MNHN, Paris, France. 573 pp.
• Bein, E., Habte, B., Jaber, A., Birnie, A. & Tengnäs, B., 1996. Useful trees and shrubs in Eritrea: identification, propagation and management for agricultural and pastoral communities. Technical Handbook No 12. Regional Soil Conservation Unit, Nairobi, Kenya. 422 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.
• Busch, J., Grether, Y., Ochs, D. & Sequin, U., 1998. Total synthesis and biological activities of (+)- and (-)-boscialin and their 1’-epimers. Journal of Natural Products 61(5): 591–597.
• Gathirwa, J.W., Rukunga, G.M., Njagi, E.N.M., Omar, S.A., Guantai, A.N., Muthaura, C.N., Mwitari, P.G., Kimani, C.W., Kirira, P.G., Tolo, F.M., Ndunda, T.N. & Ndiege, I.O., 2007. In vitro anti-plasmodial and in vivo anti-malarial activity of some plants traditionally used for the treatment of malaria by the Meru community in Kenya. Journal of Natural Medicines 61(3): 261–268.
• Gathirwa, J.W., Rukunga, G.M., Njagi, E.N.M., Omar, S.A., Mwitari, P.G., Guantai, A.N., Tolo, F.M., Kimani, C.W., Muthaura, C.N., Kirira, P.G., Ndunda, T.N., Amalemba, G., Mungai, G.M. & Ndiege, I.O., 2008. The in vitro anti-plasmodial and in vivo anti-malarial efficacy of combinations of some medicinal plants used traditionally for treatment of malaria by the Meru community in Kenya. Journal of Ethnopharmacology 115(2): 223–231.
• Hussain, R.A., Lin, Y.M., Poveda, L.J., Bordas, E., Chung, B.S., Pezzuto, J.M., Soejarto, D.D. & Kinghorn, A.D., 1990. Plant-derived sweetening agents: saccharide and polyol constituents of some sweet-tasting plants. Journal of Ethnopharmacology 28(1): 103-115.
• Kazembe, T.C. & Nkomo, S., 2010. Mosquitocides of Ageratum conyzoides, Boscia salicifolia and Grewia monticola. Indian Journal of Traditional Knowledge 9(2): 394–397.
• Mbuya, L.P., Msanga, H.P., Ruffo, C.K., Birnie, A. & Tengnäs, B., 1994. Useful trees and shrubs for Tanzania: identification, propagation and management for agricultural and pastoral communities. Technical Handbook 6. Regional Soil Conservation Unit/SIDA, Nairobi, Kenya. 542 pp.
• Neuwinger, H.D., 1998. Afrikanische Arzneipflanzen und Jagdgifte. Chemie, Pharmakologie, Toxikologie. 2nd Edition. Wissenschaftliche Verlagsgesellschaft mbH, Stuttgart, Germany. 960 pp.

Other references

• Adjanohoun, E.J., Ahyi, M.R.A., Aké Assi, L., Dan Dicko, L., Daouda, H., Delmas, M., de Souza, S., Garba, M., Guinko, S., Kayonga, A., N'Golo, D., Raynal, J. & Saadou, M., 1985. Médecine traditionnelle et pharmacopée - Contribution aux études ethnobotaniques et floristiques au Niger. Agence de Coopération Culturelle et Technique, Paris, France. 250 pp.
• Andrews, F.W., 1950. The flowering plants of the Anglo-Egyptian Sudan. Volume 1. Buncle, Arbroath, United Kingdom. 237 pp.
• Beentje, H.J., 1994. Kenya trees, shrubs and lianas. National Museums of Kenya, Nairobi, Kenya. 722 pp.
• Berhaut, J., 1974. Flore illustrée du Sénégal. Dicotylédones. Volume 2. Balanophoracées à Composées. Gouvernement du Sénégal, Ministère du Développement Rural et de l’Hydraulique, Direction des Eaux et Forêts, Dakar, Sénégal. 695 pp.
• Burkill, H.M., 2000. The useful plants of West Tropical Africa. 2nd Edition. Volume 5, Families S–Z, Addenda. Royal Botanic Gardens, Kew, Richmond, United Kingdom. 686 pp.
• Elffers, J., Graham, R.A. & Dewolf, G.P., 1964. Capparidaceae. In: Hubbard, C.E. & Milne-Redhead, E. (Editors). Flora of Tropical East Africa. Crown Agents for Oversea Governments and Administrations, London, United Kingdom. 88 pp.
• Geerling, C., 1982. Guide de terrain des ligneux Sahéliens et Soudano-Guinéens. Mededelingen Landbouwhogeschool Wageningen 82–3. Wageningen, Netherlands. 340 pp.
• Gelfand, M., Mavi, S., Drummond, R.B. & Ndemera, B., 1985. The traditional medical practitioner in Zimbabwe: his principles of practice and pharmacopoeia. Mambo Press, Gweru, Zimbabwe. 411 pp.
• Hauman, L. & Wilczek, R., 1951. Capparidaceae. 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 2. Institut National pour l’Étude Agronomique du Congo belge, Brussels, Belgium. pp. 454–521.
• Hedberg, I., Hedberg, O., Madati, P.J., Mshigeni, K.E., Mshiu, E.N. & Samuelsson, G., 1982. Inventory of plants used in traditional medicine in Tanzania. I. Plants of the families Acanthaceae-Cucurbitaceae. Journal of Ethnopharmacology 6(1): 29–60.
• Kers, L.E., 1986. Capparidaceae. Flore du Cameroun. Volume 29. Muséum National d’Histoire Naturelle, Paris, France. 141 pp.
• Kers, L.E., 2000. Capparidaceae. In: Edwards, S., Mesfin Tadesse, Demissew Sebsebe & Hedberg, I. (Editors). Flora of Ethiopia and Eritrea. Volume 2, part 1. Magnoliaceae to Flacourtiaceae. The National Herbarium, Addis Ababa University, Addis Ababa, Ethiopia and Department of Systematic Botany, Uppsala University, Uppsala, Sweden. pp. 74–120.
• Kokwaro, J.O., 1993. Medicinal plants of East Africa. 2nd Edition. Kenya Literature Bureau, Nairobi, Kenya. 401 pp.
• Luoga, E.J., Witkowski, E.T.F. & Balkwill, K., 2004. Regeneration by coppicing (resprouting) of miombo (African savanna) trees in relation to land use. Forest Ecology and Management 189: 23–35.
• 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.
• Neuwinger, H.D., 2000. African traditional medicine: a dictionary of plant use and applications. Medpharm Scientific, Stuttgart, Germany. 589 pp.
• Newmark, W.D., 2001. Conserving biodiversity in East African forests: a study of the eastern arc mountains. Ecological Studies 155. Springer, Berlin, Germany. 197 pp.
• von Maydell, H.-J., 1986. Trees and shrubs of the Sahel: their characteristics and uses. Schriftenreihe der GTZ No 196. Deutsche Gesellschaft für Technische Zusammenarbeit, Eschborn, Germany. 525 pp.
• Walter, A. & Sequin, U., 1990. Flavonoids from the leaves of Boscia salicifolia. Phytochemistry 29(8): 2561–2563.
• Wild, H., 1960. Capparidaceae. In: Exell, A.W. & Wild, H. (Editors). Flora Zambesiaca. Volume 1, part 1. Crown Agents for Oversea Governments and Administrations, London, United Kingdom. pp. 195–245.

Sources of illustration

• Andrews, F.W., 1950. The flowering plants of the Anglo-Egyptian Sudan. Volume 1. Buncle, Arbroath, United Kingdom. 237 pp.
• Arbonnier, M., 2004. Trees, shrubs and lianas of West African dry zones. CIRAD, Margraf Publishers Gmbh, MNHN, Paris, France. 573 pp.
• Berhaut, J., 1974. Flore illustrée du Sénégal. Dicotylédones. Volume 2. Balanophoracées à Composées. Gouvernement du Sénégal, Ministère du Développement Rural et de l’Hydraulique, Direction des Eaux et Forêts, Dakar, Sénégal. 695 pp.

Author(s)

• R.H.M.J. Lemmens, PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands

Correct citation of this article

Lemmens, R.H.M.J., 2013. Boscia salicifolia Oliv. In: Schmelzer, G.H. & Gurib-Fakim, A. (Editors). PROTA (Plant Resources of Tropical Africa / Ressources végétales de l’Afrique tropicale), Wageningen, Netherlands. Accessed 18 December 2024.

• See this page on the Prota4U database.