Ecological distribution, diversity and use of the genus Digitaria Haller (Poaceae) in Senegal

The genus Digitaria Haller is one of the most important of grass flora of Senegal by both its specific richness and the socio-economic value of its species. Despite this importance, no studies have been done specifically on these species. This study aims, therefore, to document the diversity, distribution, ecology and usefulness of the genus of such species for raising public awareness about botanical, ecological distribution, and status of such species and their uses in Senegal. Data collection approach was based on field work conducted in Senegal that has allowed the preparation of distribution maps of species related to ecological factors such as climate, vegetation and soil coupled with a literature review used to determine the use of species. Consequently, literature accessed has revealed that various species of Digitaria exist and they consist mainly of weeds, forage or food crops. Digitaria spp. has a wider distribution with some species having a broader distribution whereas others are restricted to some African regions. They are generally encountered throughout the tropics including in rainforests, savannas and steppes; wherein soils are sandy and acidic types. In Senegal, most of the species are found in the south under a Sudano-Sahelian zone, growing on almost all vegetation and soil types. This study, which is a contribution to the improvement and preservation of the living environment of these species, is an important step for the facilitation of any conservation action. It also encourages a greater appreciation of the value of these species, which are potential sources of genes from Digitaria exilis, the cultivated species.   Key words: Digitaria, climatic zones, vegetation types, soil types, conservation, Senegal.