Arthonia diffusella Fink ex J. Hedrick
CC BY-NC 3.0 - United States National Herbarium - Smithsonian (US:Lichens) - Source: https://lichenportal.org/portal/taxa/index.php?taxon=52418
Leg. C. Wetmore Nr: 28638 1977-07-12 Canada, Ontario, Slate Islands, Patterson Island around old lumber camp on McGreevy Harbour.
