We present a robust, five-locus phylogeny of the Megasporaceae and, based on this, propose several taxonomic innovations. The new genus Antidea is erected for Aspicilia brucei, which occupies a position near the base of the phylogeny, and the new species Aspicilia indeterminata and A. suavis are described from Montana. We also show that all North American (and some European) records of Aspilidea myrinii are misidentifications with many representing a second species in the genus, differing from A. myrinii by having elevated apothecia and narrower ascospores and for which we make the new combination Aspilidea subadunans. Finally, we make the new combinations Lobothallia determinata and L. peltastictoides, and report the lichenicolous fungus Sagediopsis aspiciliae (on A. subadunans) as new to North America.

The new lichenicolous fungus Llimoniella cinnabarinae growing on Ramboldia cinnabarina from Alaska is described. The lack of excipular or epihymenial K+ purplish, violet or green pigments places it near the recently described L. phaeophysciae group. Its affinity with Llimoniella and other members of lichenicolous Helotiales is discussed.