Abstract:
In a historical revue of the nomenclature of A. karroo it is clear that different authors have already been aware of the fact that several variating forms do exist in the taxon A. karroo. They even described some of the variations as new species! A single population of A. karroo has been studied beforehand in order to obtain a proper set and quantity of characteristics for numeric taxonomic analysing purposes. 1 Altogether 38 characteristics have been carefully selected beforehand in order to use in the analysis of the variations of A. karroo. Different populations of the geographical distribution area of A. karroo in southern Africa were thoroughly studied and analysed by means of computerized numerical taxonomic methods. Environmental characteristics of the different populations were also quoted. The anatomy of the pinnule have also been studied. According to the results it seems that six well defined infraspecific groups are distinguishable. The seedlings of these six groups were cultivated under similar environmental conditions and show the same range of phenetic variation as the six above mentioned groups. It proves that these infraspecific groups' characteristics have already been genetically fixed. Though there are even further subvariations in some of the six infraspecific variating forms, the six variations can still be distinguished from one another: They are well defined groups with a taxonomic rank of at least that of subspecies. These different infraspecific groups of A. karroo as well as two interspecific hybrid forms are described in detail. Their geographical distribution in southern Africa as well as certain ecological characteristics are also provided in this thesis. Probable new name combinations for new subspecies are suggested in case these six infraspecific groups might in future be regarded as subspecies. A key to distinguish between the different groups are also provided.
