Software dependent phenetic relationships of non-nodulating African species of Acacia

The phenetic analysis of non-nodulating Acacia species by Harrier et al. (1 997) was repeated to illustrate how different computer programs may generat e alternative UPGMA trees for the very same data, even in the absence of da ta input order effects (ties). For example, all Harrier et al.'s UPGMA dend rograms produced by software from the Scottish Agricultural Statistics Serv ice differed from those obtained by the packages NTSYS and MVSP87. Particul arly, the positions of A. albida, A. rovumae, and A. pentagona, as well as the relationships between Diacanthae and Triacanthae were affected by this phenomenon. Hence, whenever: clustering techniques are used, care should be taken to consider possible software-dependent caveats and artefacts. Never theless, all programs provided clusterings that largely coincided with the subgeneric and sectional groupings proposed by Vassal (1972) although the p ositions of some species varied depending on whether morphological or molec ular data were considered (e.g. A. albida and A. rovumae).