A New Lichenized Fungal Species from East Antarctica: Austroplaca giginyakii

Austroplaca giginyakii sp. nov., a new lichenized fungus species discovered in East Antarctica, is described and its taxonomic status is evaluated using an integrative approach. The species was investigated through morphological, chemical, and molecular (nrITS) analyses. Phylogenetic results based on ITS sequences indicate that A. giginyakii forms a distinct clade within the genus Austroplaca. Although morphologically similar to A. darbishirei, it is distinguished by its deeper red-orange thallus, blastidiate soralia, and blastidia dispersed over the entire thallus surface rather than being confined to squamule margins. ITS sequence comparisons confirm its genetic distinctiveness. The type specimen was found growing on mosses and lacks both apothecia and pycnidia. Combined morphological and molecular evidence supports the recognition of A. giginyakii as a new species.