Phylogenetic Analysis of the Lichen Family Umbilicariaceae based on nuclear ITS1 and ITS2 rDNA Sequences

The lichen family Umbilicariaceae is accepted by most lichenologists as consisting of two genera, Lasallia and Umbilicaria . The monophyly of these two genera was examined by phylogenetic analyses of nucleotide sequences of ITS 1 and ITS2 rDNA. Sequences of these regions from three Lasallia and 17 Umbilicaria species were aligned to those of seven representatives of the outgroup taxa including Eurotiales, Onygenales and Caliciales ( Mycocaliciaceae ) and subjected to maximum parsimony, maximum likelihood and neighbour-joining analyses. The resulting phylogenetic hypotheses supported the monophyly of the representative species of Lasallia . However, the species of Umbilicaria did not form a monophyletic sistergroup to Lasallia due to the basal placement of other Umbilicaria species in some analyses. Based on these analyses, if Lasallia is recognized as a separate genus then Umbilicaria appears to be paraphyletic. Although further taxon sampling is required to resolve the monophyly of Umbilicaria , for the present we recommend retaining the current treatment of Lasallia as separate from Umbilicaria .