Psora mediterranea (Lecanorales, Psoraceae), a new lichen species from Europe, including a new concept for P. himalayana and a revised key to the European species

Abstract Herein, we describe Psora mediterranea , found in the Mediterranean region of Europe. Previously misidentified as Psora pseudorussellii based on morphology, P. mediterranea has a distinct molecular lineage and geographic distribution. This new species is phylogenetically the sister to a species that we henceforth epitypify as Psora himalayana , from the Himalayas. These sister Psora taxa are distinct due to morphology, current known geographic range, and preferred habitat. We provide two updated keys to the Psora species in Europe, including a key with morphologically similar species that may be confused with Psora in this region and a simplified “hand lens” key. To assist with ongoing DNA barcoding of lichens, we publish the first barcode ITS sequences from Psora gresinonis (an isotype) and the first sequences of P. pseudorussellii from North America. We also include sequences from understudied taxa, including Glyphopeltis , Romjularia , and Protomicarea . Further, we suggest updates to the circumscription of the Psoraceae by suggesting a new family for Glyphopeltis , Glyphopeltidaceae , and supporting the placement of Protomicarea in the Pilocarpaceae. Graphical Abstract