Diversity of medicinal plants in West African habitats

This paper examines the habitats of 439 species of wild and cultivated plants in West Africa which are used in traditional medicine. About 30% of the medicinal plants in West Africa (138 species) are introduced into cultivation for other economic reasons. Most medicinal plants still grow in the wild, with 95 species in tropical closed forests (medicinal plant diversity H = 1.66), 80 species in secondary forests and regrowth (H = 1.34) and 82 species in savanna woodlands (H = 1.19). Sahel savanna arid lands and coastal sandy beach habitats are just as diverse with H = 1.55 but with only 31 medicinal species (7.1% of total). Wetland ecosystems are the least diverse (H = 0.90) and only a few medicinal plants are found in mangrove swamps and inland freshwater swamps (3.0%). The most important medicinal plants are understorey trees and shrubs in tropical closed forests (57.9%), not the timber trees; in tropical forest regrowth, the most important are scrambling shrubs and farmbush forbs (62.5%); trees and shrubs are important in savanna woodlands (75.6%) and also in the Sahel savanna.