Phylogeny and Taxonomy of Polyblastia and allied taxa (Verrucariaceae)

Sammanfattning: Polyblastia A. Massal. is a genus of lichenized fungi belonging to Verrucariaceae (Ascomycota). Traditional classification heavily rested on a few cardinal characters, primarily ascoma structure and spore morphology, but the delimitation of Polyblastia was problematic. Using DNA sequences from nucLSU, and RPB1 the position of the ‘Polyblastia group’, as a strongly supported clade within Verrucariaceae, was confirmed. A three marker phylogeny (including nucITS) based on a wide taxon sampling reveals strongly supported clades within the ‘Polyblastia group’. Thus Polyblastia s.str. is recognized. The phylogeny of the strongly supported Thelidium clade is not completely resolved. In a different clade, Verrucaria rupestris, the type of Verrucaria, is a sister to the Henrica melaspora/H. theleodes clade. Trimmatothele perquisita, the type of Trimmatothele, forms a strongly supported group with a Verrucaria species. The genus Sporodictyon, until recently included in Polyblastia, is resurrected.Species delimitation in Sporodictyon is investigated, and the morphological variation within and between the monophyletic groups is evaluated in an effort to reconcile morphological and molecular data. A taxonomic revision of Sporodictyon, occurring in Northern Europe and the adjacent Arctic is provided, and two new species are described. A comprehensive material is investigated, a key to the species is provided.A generic revision of the family Verrucariaceae, based on recent molecular phylogenetic analyses and previous morphological studies, is offered. Three new genera (Hydropunctaria, Parabagliettoa and Wahlenbergiella) are proposed. Several other monophyletic groups are identified for which the taxon sampling is insufficient for proposing taxonomic changes. The nomenclature of the genera in the family is revised, including the study of type materials and several lectotypifications are suggested.The new genus Atla (Verrucariaceae) is described, and three new species to science, A. alpina, A. palicei and A. praetermissa, are included. An identification key to the species and a revision of the genus is supplied.