A new Agonimia from Europe with a flabelliform thallus

Agonimia flabelliformis sp. nov. (Verrucariaceae, Ascomycota) is described as a new species from the Czech Republic, Germany and Great Britain. Except for the distinctive, flabelliform to minutely coralloid thallus the species mostly resembles A. allobata. It differs from other related species of Agonimia in the absence of cortical papillae and in ascospore size. The distinctness of the new species and its placement within the genus Agonimia is supported by analyses of mitochondrial small subunit ribosomal DNA sequences from several samples of the taxon, and from many other representatives of Verrucariales including newly sequenced A. repleta and A. vouauxii. Additionally, ITS rDNA sequence data supports the distinction of A. flabelliformis from A. allobata. However, A. allobata was found to be highly variable and relationships, as well as the monophyly of taxa within Agonimia, are still unresolved and need further investigation.