Altitudinal range: from the submediterranean/colline belt (potential vegetation: mixed deciduous forests dominated by Quercus and Carpinus) to the montane belt (potential vegetation: deciduous forests dominated by Fagus sylvatica and closed coniferous forests with Picea abies)
Note: in the protologue the name is given as “P. muelleri Hepp in litt.”. As there is no indication that the diagnosis has been provided by Hepp too, the name has to be attributed to the author of the publication (ICN Art. 46.5). A species with a habitus somewhat intermediate between those of Lathagrium cristatum and Scytinium lichenoides: black lobes with lobulate margins, richly fertile along the margins and on the tips, with punctiform and urceolate apothecia; on boulders along streams and rivers (at the type locality together with Lichinella heppii).
