Xanthoria tendraensis sp. nov. and Xanthorietum tendraensis ass. nova from the northern Black Sea coast (Ukraine)

A new species, Xanthoria tendraensis (Teloschistales, Lecanoromycetes), is described from species-poor lichen communities on shell dunes of the Tendra Spit (northern Black Sea coast, Ukraine), based both on morphological and molecular data. This lichen is similar to X. ectaneoides but differs in having longer ascospores with thicker walls at the poles. A new lichen association, Xanthorietum tendraensis, is described from stable grey dunes. Its characteristic species are Lecania sylvestris s. lat., Polyozosia perpruinosa, Scythioria phlogina and X. tendraensis. The species composition of the new association is similar to communities of Aspicilion contortae (Verrucarietea nigrescentis). Six new sequences of nrITS region were obtained for Xanthoria tendraensis, Xanthocarpia fulva s. lat. and Trebouxia crenulata, which was identified as a photobiont of X. tendraensis.