Buellia species with pluriseptate spores: New and unrecorded species in North America

Four exclusively North American species new to science are described, Buell ia muriformis, B. oidaliella, B. terricola, and B. triseptata, They are com pared with related species such as B. penichra, B. oidalea, B. geophila, an d B. triphragmioides, respectively. Buellia cedricola and B. subdispersa ar e reported from North America for the first time and B. tolucae from the Un ited Stares. Distribution maps are given, and a key to all North American B uellia species with pluriseptate spores is provided along with comments on same of the species previously recorded from North America. Buellia cedrico la and B. subdispersa are lectotypified and a neotype for B. tolucae is des ignated.