XVI International Botanical Congess

The molecular systematic analyses of 14 species in the Umbilicariaceae are based on nrDNA ITS sequences. The phylogenetic hypothesis using parsimony analysis suggests that the number and size of ascospore combined with the thallus pustulate or non-pustulate can be used as characters to distinguish genera within the family. The genera Umbilicaria and Lasallia are shown to be monophyletic. In addition, there are a few conspecific and allospecific species having eastern Asian, North American disjunctions in the Umbilicariaceae. A special emphasis on some disjunctions and vicariisms, such as U. esculenta, U. mammulata, U. muehlenbergii, L. pensylvanica, etc. is addressed based on the four sequences sets representing different regions (ITS1, 5.8S, ITS2 and 25S(partial)) of the nrDNA.