Scutula tuberculosa , the correct name of the Scutula growing on Solorina spp., with a key to Scutula s. str. in the Northern Hemisphere

The taxonomic and nomenclatural status of the common Scutula (Ramalinaceae, Lecanorales, Ascomycota) parasitizing species of Solorina (Peltigeraceae, Lecanorales) is clarified. The type of Biatorina tuberculosa Th. Fr., which, according to the protologue, was described from a Peltigera, is actually growing on Solorina saccata, and the correct name for this species is here shown to be Scutula tuberculosa (Th. Fr.) Rehm. Lectotypes are designated for Lecidea solorinaria Nyl., Scutula krempelhuberi Korb. and Lecidea solorinicola Vain. Notes on the taxonomy and classification of the genus are given, and a key to the species of Scutula s. str. in the Northern Hemisphere is presented. Scutula tuberculosa is reported as new to Asia and North America.