Two new calcicolous caloplacoid lichens from South Korea, with a taxonomic key to the species of Huriella and Squamulea

Pyrenodesmia rugosa Lee & Hur and Huriella aeruginosa Lee & Hur are described as new lichen-forming fungi from a calcareous mountain of South Korea. Pyrenodesmia rugosa is distinguishable from Pyrenodesmia micromontana (Frolov, Wilk & Vondrak) Hafellner & Turk, the most similar species, by thicker thallus, rugose areoles, larger apothecia, shorter hymenium, shorter hypothecium and narrower tip cells of paraphyses. Huriella aeruginosa, the second new species, differs from 'Squamulea' chelonia Bungartz & Sochting by dark greenish-grey to grey thallus without pruina, gold to yellow-brown epihymenium, larger ascospores and thallus K- and KC- reaction. Molecular analyses employing internal transcribed spacer (ITS), mitochondrial small subunit (mtSSU) and nuclear large subunit ribosomal RNA (LSU) sequences strongly support the two caloplacoid species to be distinct in their genera. A surrogate key is provided to assist in the identification of all 20 taxa in Huriella and Squamulea.