A phylogenetic framework for reassessing generic concepts and species delimitation in the lichenized familyTrypetheliaceae(Ascomycota: Dothideomycetes)

Abstract

AbstractWe provide an expanded and updated, 2-locus phylogeny (mtSSU, nuLSU) of the lichenized fungal familyTrypetheliaceae, with a total of 196 ingroup OTUs, in order to further refine generic delimitations and species concepts in this family. As a result, the following 15 clades are recognized as separate genera, including five newly established genera:Aptrootia,Architrypethelium,Astrothelium(including the bulk of corticate species with astrothelioid ascospores; synonyms:Campylothelium,Cryptothelium,Laurera),Batheliums. str. (excludingB. degeneransand relatives which fall intoAstrothelium), the reinstatedBogoriella(for tropical, lichenized species previously placed inMycomicrothelia),Constrictoluminagen. nov. (for tropical, lichenized species ofArthopyrenia),Dictyomeridiumgen. nov. (for a subgroup of species with muriform ascospores previously placed inPolymeridium),Julella(provisionally, as the type species remains unsequenced),Marcelaria(Laurera purpurinacomplex),Nigrovotheliumgen. nov. (for theTrypethelium tropicumgroup),Novomicrotheliagen. nov. (for an additional species previously placed inMycomicrothelia),Polymeridiums. str.,Pseudopyrenula,Trypetheliums. str. (T. eluteriaegroup), andViridotheliumgen. nov. (for theTrypethelium virensgroup). All recognized genera are phenotypically characterized and a discussion on the evolution of phenotypic features in the family is given. Based on the obtained phylogeny, species delimitations are revised and the importance of characters such as thallus morphology, hymenial inspersion, and secondary chemistry for taxonomic purposes is discussed, resulting in a refined species concept.