Porina pseudohibernica sp. nov., an isidiate, epiphytic lichen from central and south-eastern Europe

The epiphytic lichenPorina pseudohibernicais described as new. It is characterized by a richly isidiate thallus, 7–8(–9)-septate ascospores and the presence of periphyses. It resemblesP. hibernicas. 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 a sterile condition from scattered localities in the humid (sub-)montane belt of Slovenia, the Czech Republic and Ukraine, occurring on smooth bark ofFagusandCarpinus.Porina hibernicais restricted to the coastal lowlands of Atlantic Europe, and it prefers rather dry, base-rich bark ofQuercusandUlmus. The characters previously used to segregate the isidiate EuropeanPorinainto the genusZamenhofiaare also discussed.