Central Europe in general is poor in Teloschistaceae lichen crusts (Caloplaca s. lat.). Diversity of these lichens is increased by the occurrence of some Arctic, Mediterranean and continental species, which are here close to the limits of their range. Examples include:
Caloplaca interfulgens, previously known from arid territories of northern Africa and western Asia, is recorded, surprisingly, from Austria, Czech Republic, Germany, Slovakia and southern Russia. In Central Europe, it is restricted to scattered xerothermic limestone outcrops.2)
Caloplaca scabrosa, previously known only from Svalbard, is recorded from the Sudetes in the Czech Republic. It is similar to, but not conspecific with, C. furfuracea. Its diagnostic characters include a blastidiate thallus and the presence of atranorin. Our results show that atranorin is absent in the majority of taxa related to C. furfuracea with only two exceptions: the sample from Eastern Carpathians, here called C. aff. scabrosa, and in one Sudetan sample identified as C. crenularia.3)
Caloplaca emilii, newly described below, is closely related to the Mediterranean C. areolata. We consider C. emilii a Mediterranean species rarely occurring in higher latitudes in Austria, the Czech Republic and Germany. It is distinguished from C. areolata mainly by the presence of vegetative diaspores (blastidia); a possible role of blastidia in the distribution pattern of C. emilii is discussed below. Status of the names Caloplaca areolata, C. isidiigera and C. spalatensisis, formerly used for the new taxon, is clarified.4)
Caloplaca molariformis, newly described below, belongs to the Pyrenodesmia group (a lineage of Caloplaca without anthraquinones). It is a continental species, frequently collected on limestone or lime-rich tuffs in steppes or deserts in Turkey, Iran, western Kazakhstan and southern Russia, and is also known from eastern Ukraine and southern Slovakia. Caloplaca molariformis is characterized by its thick thallus with fungal and algal tissues arranged in high stacks.5)
Caloplaca substerilis, newly described below, is distinguished from the closely related C. ulcerosa by its endophloeodal or minutely squamulose thallus with soralia formed in bark crevices or on margins of squamules. While C. ulcerosa has a maritime distribution in Europe, C. substerilis is typically a continental species. North American continental lichens called “C. ulcerosa” are phylogenetically closer and more similar to C. substerilis.
The positions within Teloschistaceae of the taxa considered are demonstrated by ITS phylogenies. The distributions of C. areolata, C. emilii and C. interfulgens are mapped. The new species are fully described using more than a hundred phenotype characters, and diagnostic characters are indicated separately.