Verrucoccum (Dothideomycetes, Dictyosporiaceae), a new genus of lichenicolous fungi on Lobaria s. lat. for the Dothidea hymeniicola species complex

Two lichenicolous fungi, one growing on the thallus of Lobaria pulmonaria in the United Kingdom (Scotland) and the other in apothecia of Lobaria linita and L. oregana in northwestern North America (Alaska and British Columbia) and northeast Asia (Russian Far East, Khabarovsk Krai), show similarities to the species originally described as Dothidea hymeniicola (later transferred to Polycoccum s. lat and Endococcus) from a Lobaria s. lat. species in Central America. Critical morphological comparison showed that, despite the superficial resemblance between Alaskan, Canadian, Russian, and Scottish collections and the holotype of Dothidea hymeniicola, they can be distinguished by detailed microscopic analyses. Using three molecular markers, sequences of the nuc 18S, 28S, and internal transcribed spacer (ITS) rDNA regions of the recent Scottish and Alaskan collections were obtained. Phylogenetic analyses confirmed separation of the species and revealed them as a new lineage in Pleosporales, for which the new generic name Verrucoccum is introduced for the three species: V. coppinsii, sp. nov., V. hymeniicola, comb. nov. (syn. Dothidea hymeniicola), and V. spribillei, sp. nov.

Automated summary

Two lichenicolous fungi growing in different regions show similarities to a previously described species, but can be distinguished through detailed microscopic analysis and molecular markers. Phylogenetic analyses confirmed their separation as a new lineage, for which a new generic name was introduced.