Revision of Immersaria and a new lecanorine genus in Lecideaceae (lichenised Ascomycota, Lecanoromycetes)

The species Immersaria cupreoatra has been included in Bellemerea. This caused us to reconsider the relationships between Bellemerea and the lecanorine species of Immersaria and to question the monophyly of Immersaria. Amongst 25 genera of the family Lecideaceae, most have lecideine apothecia, the exceptions being Bellemerea and Koerberiella, which have lecanorine apothecia. According to previous classifications, Immersaria included species with both lecanorine and lecideine apothecia. A five-loci phylogenetic tree (nrITS, nrLSU, RPB1, RPB2, and mtSSU) for Lecideaceae showed that Immersaria was split into two clades: firstly, all the lecideine apotheciate species and secondly, all the lecanorine apotheciate species. The latter clade was closely related to the remaining lecanorine apotheciate genera: Bellemerea and Koerberiella. Therefore, the genus concept of Immersaria is revised accordingly and a new lecanorine genus Lecaimmeria is proposed. Furthermore, four new species for Immersaria and seven new species and three new combinations for the new genus Lecaimmeria are proposed. Keys to Immersaria and the new genus Lecaimmeria are provided.