Genus Dimerella (Coenogoniaceae, lichenized Ascomycota) in Slovakia

Abstract

The genus Dimerella, comprising ca 25 species worldwide, was studied to clarify its occurrence in Slovakia. The paper, based on literature review, revision of collections (BP, BRA, PR, PRC, SAV, W, herb. Vfezda, herb. Pi{út) and fieldwork, brings together evidence of two species, D. pineti and D. lutea. The first voucher specimens and published data for D. pineti date back to the second half of 19th century; 20th century records are only occasional, therefore the species was regarded as rare. However, this investigation shows that it is widely distributed throughout Slovakia, mainly on tree bases, stumps or mossy soil in forests. The sub-oceanic D. lutea is recorded from Slovakia for the first time. Its historical occurrence in the Vihorlat Mounts complements our current observation in the Eastern Carpathians (Bukovské vrchy Mts) in 2002. From an investigation of its ecological requirements, it is evident that the species is confined to humid, well preserved forest biotopes. Within the studied territory the species has not been overlooked, but is extremely rare, which is the reason for including it in the Red List of Lichens of Slovakia as critically endangered. Vernacular names for both the species are introduced