The distribution of Platismatia wheeleri was determined using the USDA Forest Service's Forest Inventory and Analysis plots in Washington, Oregon, Idaho and California and was compared to that of P. glauca on the same set of plots. Platismatia glauca inhabits a broad climatic niche, living in areas with 34 to 325 frost-free days and moderate to high May through September precipitation (100–425 mm). Platismatia wheeleri inhabits an ecotone between forested, mountainous regions and drier regions with open canopies. These plots, with 225 to 300 frost-free days, are on the warm end of the P. glauca habitat. The co-occurrence of these species on several plots and overlapping climate niches suggest either historic separation of populations that now co-occur; sympatric speciation; or a more complex pattern within this widely-distributed, variable species.

Grimmia serrana is a species new to the moss flora of Oregon; it was formerly considered a California endemic. The new record is based on a specimen collected in Douglas County, Oregon by the author in May of 2020. Species and site descriptions, site-specific photographs, and specimen photographs are provided.

The lichenicolous fungi Calycina alstrupii, Clypeococcum cladonema, Laetisaria lichenicola and Stigmidium humidum are reported as new to North America. The hepaticolous fungus Epibryon hypophyllum is reported as new to western North America. The lichenicolous fungi Sphaerellothecium pumilum and Stigmidium gyrophorarum are reported as new to northwestern North America. The hepaticolous fungus Epibryon metzgeriae is reported as new to the USA, and the lichenicolous fungi Niesslia lobariae, Plectocarpon nephromeum and Protounguicularia nephromatis are reported as new to the contiguous 48 states of the USA. Extra-limital records for the taxa Cercidospora stenotropae, Epibryon bryophilum s. lat. and E. casaresii s. lat. are discussed.

We provide a list of 15 lichens and allied fungi that are currently only known to occur in Canada. Our analysis builds on previous initiatives to identify nationally endemic species. Some of these species are newly described and occur in southern Canada and may still be discovered in the United States. Five species occur in areas that have been identified as hotspots for nationally endemic species. These results can be used to prioritize species assessments and conservation actions in Canada. Our approach can also be applied to refine Canada's list of nationally endemic species for other cryptic taxonomic groups.