Four new epiphytic species in theMicarea prasinagroup from Europe

In this study we clarify the phylogeny and reassess the current taxonomy of theMicarea prasinagroup, focusing especially on theM. byssaceaandM. micrococcacomplexes. The phylogeny was investigated using ITS, mtSSU andMcm7regions from 25 taxa belonging to theM. prasinagroup. A total of 107 new sequences were generated. Data were analyzed using maximum parsimony and maximum likelihood methods. The results reveal five undescribed well-supported lineages. Four of the lineages represent new species described asMicarea pseudomicrococcaLaunis & Myllys sp. nov.,M. czarnotaeLaunis, van den Boom, Sérusiaux & Myllys sp. nov.,M. microareolataLaunis, Pykälä & Myllys sp. nov. andM. laetaLaunis & Myllys sp. nov. In addition, a fifth lineage was revealed that requires further study.Micarea pseudomicrococcais characterized by an olive green granular thallus, small cream-white or brownish apothecia lacking the Sedifolia-grey pigment and two types of paraphyses up to 2 µm wide.Micarea czarnotaeforms a granular, densely granular or continuous olive green thallus, convex to hemispherical apothecia often with the Sedifolia-grey pigment and no crystalline granules in the thallus.Micarea microareolatais characterized by a ± pale green areolate thallus (composed of goniocysts), cream-white apothecia lacking the Sedifolia-grey pigment and narrow spores.Micarea laetahas a vivid to olive green granular thallus, pale apothecia lacking the Sedifolia-grey pigment and wider spores compared toM. microareolata. Descriptions, images and a key are provided for the new species. Crystalline granules are introduced as a novel species-level character forMicarea.