Circinaria grossheimii (Megasporaceae, lichenized ascomycetes): phylogeny, distribution, and corrected morphological and anatomical descriptions

Corrected anatomical and morphological data on Aspicilia grossheimii Oxner, a little-known crustose lichen species described from the Absheron Peninsula (Azerbaijan) are presented. The species has areolate, 1–5 mm thick, yellowish-white, grayish to greenish thallus, large apothecia up to 4 mm diam., surrounded by a whitish thalline margin, large spheroid spores, 20–34 µm diam., 1–4 per ascus, branching, moniliform paraphyses, and 8–14 µm long pycnoconidia, that characterize it as a representative of the genus Circinaria. According to the phylogenetic tree assembled using nuITS, nuLSU and mtSSU loci, Aspicilia grossheimii does not have close relationships with any known taxon within Circinaria. The species is known from Azerbaijan, Georgia, Russia (Republic of Daghestan and Astrakhan Region), and Romania (Dobrogea). A new combination, Circinaria grossheimii (Oxner) Paukov, Alverdiyeva et Ismailov, is proposed. Aspicilia calcarea var. dobrogensis Vězda is synonymized with Circinaria grossheimii.