Phylogenetic studies in the Candelariaceae (lichenized Ascomycota) based on nuclear ITS DNA sequence data.

The phylogeny of the lichen family Candelariaceae was investigated using nucleotide sequences from the ITS region of the nuclear ribosomal DNA. 23 species of Candelariella, 6 species of Candelaria, 2 species of Candelina and 2 species of Placomaronea were included in the study. Acarospora cervina and Pleopsidium chlorophanum were used as outgroup species. The phylogenetic analysis were performed using maximum parsimony and Bayesian MCMC inference. The resulting trees were poorly resolved and strong support were only found for terminal clades. The results indicate, however, that polyspored asci have evolved a limited number of times within the family and appear within four clades. One of these clades comprises the core group of Candelariella including the type species C. vitellina. Placomaronea and Candelina both form strongly supported monophyletic clades, but neither genera are distinctly morphologically separated from Candelariella, and their positions in the tree are uncertain. The genus Candelaria is probably polyphyletic and should possibly be restricted to comprise only polyspored species with a lower cortex.