XVI International Botanical Congess

The last formal treatment of the genus Pelargonium was by R. Knuth in 1912 and was based predominantly on vegetative and floral morphology. Currently the genus is classified into 16 sections based on data from comparative morphology, karyology, phytochemistry and palynology produced by laboratories from England, Germany, South Africa and the US. From recent molecular systematic studies using cladistic analysis of DNA sequences obtained from three genomes, some of these sections are shown to be non-monophyletic. In the light of this molecular phylogenetic hypothesis the classification of Pelargonium is re-appraised to reflect evolutionary relationships.