Generic delimitations in African groups which also have wide distributions outside Africa

Abstract

At least at the generic level, the African continent is not isolated, i.e. many genera are not restricted to that continent. Which genera are endemic and which are not can be established only after extensive and thorough research in most cases. This research may reveal connections not known before or lead to the rupture of entities in two or more parts along continental boundaries. At least some knowledge of the family on a worldwide scale is needed to know where to look for possible connections. These connections with other continents may be to the East or to the West, quite often dependent on the family or subfamily in question. In Africa, the taxonomic exploration of the tropical lowland rain forest started much later than in the other continents, which may have important consequences of priority in nomenclature. Before the colonial era, botanists worked on a mondial or at least on a continental scale. In colonial times taxonomists restricted themselves to a colony, a national possession, frequently, in competition with colleagues from other colonial powers working for their colonies. The more genera and species they published the better, often with severe consequences for the quality of their work. At present taxonomists are gradually returning to the continental or cosmopolitical scale and do more monographic work. A rapid production of a good generic monograph is no longer possible. Examples of several African groups will be given to illustrate the different aspects of the problems encountered