A preliminary phylogeny of theLecanora saligna-group, with notes on species delimitation

Abstract

AbstractLecanoras. lat. is a genus of crustose, rarely placodioid lichens comprisingc. 1000 recognized species and subdivided into several morphology-based groups. Some of these groups have been supported in phylogenetic analyses and segregated as new genera. One of the remaining groups that has not been previously studied by molecular methods in much detail, theL. saligna-group, includes corticolous and lignicolous crustose lichens, usually containing isousnic or usnic acid (or both) as major secondary metabolites. As part of our ongoing project ‘Lecanomics’, a phylogenetic analysis based on two loci was conducted and found theL. saligna-group to be divided into two main clades and several well-supported minor clades. TheL. variaclade, chosen as one of the outgroups, emerged within theL. saligna-group. The majority of the clades are characterized by phenotypic differences. However, several well-supported clades share similarities with their sister groups, suggesting that species circumscriptions based solely on phenotypic characters may be too conservative to characterize the true species diversity present within the group. Also, there is evidence for some geographical separation of lineages; for example, most North American individuals, previously known asLecanora salignaandL. albellula, form two clades separate from their European namesakes and are here preliminarily called ‘Lecanorasp. B’, ‘Lecanorasp. C’ and ‘Lecanorasp. D’. However,L. salignaandL. albellulaalso appear to occur in North America, and some specimens from the Caucasus and Iran cluster within the North American clades.Lecanora anoptaandL. subravidaare reported for the first time from Iran.