Polyblastidium casarettianumPolyblastidium casarettianum is a species of corticolous, foliose lichen in the family Physciaceae.TaxonomyThe species was first scientifically described in 1853 by the Italian botanist Abramo Bartolommeo Massalongo, who classified it in the genus Anaptychia. Vittore Benedetto Antonio Trevisan de Saint-Léon reclassified it in genus Heterodermia in 1868. It was transferred to the newly circumscribed genus Polyblastidium in 2015 by Klaus Kalb.