XVI International Botanical Congess

There is now wide acceptance of the idea that classifications should unambiguously reflect phylogeny and that taxa should be monophyletic. It is surprising, however, that taxonomic groups, as presented in courses in plant systematics or treated in floristic studies are often traditionally defined and non-monophyletic. In fact, we see an increasing divergence and isolation of phylogenetic and floristic researchers. We recommend the rapid incorporation of well supported phylogenetic hypotheses into both floristics and teaching. We outline criteria for accepting novel taxonomic circumscriptions and discuss the implications of the application of alternative systems of nomenclature in floristics and teaching. Increased collaboration of molecular and traditional systematists is desirable, and a widely available, easily accessible, and frequently updated database of cladistic analyses of vascular plants is an urgent need. Certainly, formal taxonomic ranks are not required in teaching (or floristics)Cthe concepts to be emphasized are monophyletic groups, their diagnostic characters, and sister-group relationships.