The principal goal of our study was to test whether ecologically and chemically different populations of lichens in thePhysconia muscigenagroup belong to a single, or multiple, species. We used sequence data from three markers (ITS rDNA, mtSSU rDNA and TEF1-alpha) for the reconstruction of phylogenetic trees based on a sampling of mostly European and Canadian populations ofP. muscigena(Ach.) Poelt,P. muscigenavar.bayeri(Nadv.) Poelt andP. isidiomuscigenaEssl.
In addition, we sought any possible geographical or ecological trends among chemotypes and haplotypes. Results show that: 1) sequence data of ITS rDNA and TEF1-alpha show large genetic variation in thePhysconia muscigenagroup, which does not correlate with geographical distribution or thallus chemistry; 2)Physconia muscigenavar.bayeriandP. isidiomuscigenaappear undifferentiated withP. muscigenain our phylogenetic trees, and the three species cannot be distinguished on the basis of ITS rDNA, mtSSU rDNA and TEF1-alpha sequences.
We therefore synonymizedPhysconia muscigenavar.bayeriwithP. muscigenaand we recombineP. isidiomuscigenaas a variety ofP. muscigena.