Published online by Cambridge University Press: 29 July 2020
A new species of Synarthonia, S. leproidica, is described from Luxembourg. Phylogenetic analyses of mtSSU and RPB2 sequences were used to determine the generic affiliation of this sterile species. Synarthonia leproidica differs from all other species of the genus by the combination of a leproid thallus and the production of psoromic acid. It is the sister species to S. muriformis in our phylogenetic analyses. The discovery of the new species suggests that other strictly sorediate lichen species might have been overlooked in Europe, even in intensely explored countries such as Luxembourg. Phylogenetic analyses further confirm the placement of Reichlingia anombrophila in the genus Reichlingia and of Synarthonia astroidestera in the genus Synarthonia. Arthonia atlantica is transferred to the genus Reichlingia as R. dendritica.