Three new species of Stigmidium and Sphaerellothecium (lichenicolous ascomycetes) on Stereocaulon

Sphaerellothecium stereocaulorum sp. nov., Stigmidium beringicum sp. nov., Stigmidium stereocaulorum sp. nov. and goniocysts are described on Stereocaulon species from the northern Holarctic. Endococcus nanellus is reported new to Alaska and Mongolia.