The genus Xanthoria (Fr.) Th.Fr. in North America
The lichenized ascomycete genus Xanthoria (Fr.) Th.Fr. (Teloschistaceae) in continental United States and Canada is revised. The following 15 species are recognized: Xanthoria borealis, X. candelaria, X. concinna, X. elegans, X. fallax, X. fulva, X. hasseana, X. mendozae, X. montana, X. oregana, X. parietina, X. polycarpa, X. sorediata, X. tenax, and X. ulophyllodes. The morphology, anatomy, secon