The epiphytic lichen Porina pseudohibernica is described as new. It is characterised by a richly isidiate thallus, 7–8(–9)-septate ascospores and the presence of periphyses. It resembles P. hibernica s.str., differing in the size and septation of ascospores, and in the dimensions of the terete, branched isidia. The new species was found fertile at a single site in the Carnic Alps (SE Alps, Italy), but it is also known in sterile condition from scattered localities in the humid (sub-)montane belt of Slovenia, the Czech Republic and Ukraine, occurring on smooth bark of Fagus and Carpinus. Porina hibernica is restricted to the coastal lowlands of Atlantic Europe, and it prefers rather dry, base-rich bark of Quercus and Ulmus. The characters previously used to segregate the isidiate European Porina into the genus Zamenhofia are also discussed.
