XVI International Botanical Congess

Pinus, with about 110 species, is the largest and most heteromorphic genus of conifers. Numerous proposals to classify the species have been made. Many of these classifications are purely artificial. The one most often utilized (Little & Critchfield 1969) suffers from this bias no less than the others. Phylogenetic reconstructions using cladistics now abound, most are based on molecular data. These only analyzed a limited sample of species and predictably gave variable results. A comprehensive analysis is still wanting. This is so because within the monophyletic genus there are both ancient, relict species and modern, rapidly evolving taxa. The fossil record, selection pressure (e.g. through co-evolution)and morphology remain important factors alongside molecular evidence and all are to be taken into account in order to construct a truly natural classification of the genus.