Data from: Myriospora molybdina comb. nov. and the identity of Acarospora hysgina

The nomenclature and taxonomy of Acarospora molybdina is revised using
morphological and molecular data. The new combination Myriospora molybdina
is proposed and Acarospora hysgina is recognized as a distinct species
while A. brunneola is reduced to synonymy with A. hysgina. In its new
circumscription Myriospora molybdina is an arctic species, in Scandinavia
only occurring in northernmost Norway. Further localities are reported
from Greenland, Russia, Svalbard and the U.S.A (Alaska). Acarospora
hysgina is the correct name for populations distributed along the west
coast of Sweden and Norway, formerly thought to belong to A. molybdina.
Localities are also reported from Canada (New Brunswick), Greenland and
the U.S.A. (Maine). The following names are lectotypified; Acarospora
brunneola, Acarospora molybdina var. confusa, Lecanora ereutica β
microcyclos, Parmelia ereutica, P. hysgina and P. molybdina.