XVI International Botanical Congess

Phylogenetic analysis of sequences from the chloroplast genes matK and rbcL and from the chloroplast trnL-F region have been used to assess the generic relationships within the pine family and infrageneric and specific relationships among the pines. Chloroplast sequence comparisons confirm the split of the type subgenus (hard pines) into an Old World clade (with two apparently relictual New World species included) and a very speciose New World clade with major radiations in the eastern and western U.S. and Mexico. Groupings within the soft pine subgenus highlight the positions of some of the unusual species placed in the pinyon pine group. Results from sequence analyses are compared to the recent classifications of the genus based largely upon morphology plus crossability.