Abstract
Sixteen sorediate epiphytic species of Lecanora with atranorin from Europe are reported here. Lecanora substerilis is described as a new species from Carpathian beech forests in the Czech Republic, Slovakia, Romania and Ukraine; it belongs to the L. subfusca group in its strict sense and is characterized by its usually verrucose thallus, sorediate apothecial margin, epihymenium with coarse granules at paraphyses tips, amphithecium with large crystals and it produces atranorin and fatty acid(s).
A new, yellow chemotype of L. barkmaniana containing pulvinic acid derivatives is recognized from Austria. Morphological, ecological and chemical variation in L. exspersa, L. farinaria and L. variolascens is discussed in detail, and brief comments on the remaining 11 species are provided.
Evaluation of the type material and molecular data indicate that the predominantly saxicolous L. caesiosora is a sorediate form of L. cenisia. Molecular data confirmed the identities of the sorediate forms of L. albella and L. allophana that are conspecific with their fertile counterparts.
New Central European localities are listed for the rare species, L. barkmaniana, L. exspersa, L. mughosphagneti, L. norvegica and L. variolascens. Positions in ITS and mtSSU phylogenies are outlined for most species.
Identification keys to fertile as well as sterile populations are provided.