The four North American species of Evernia, E. divaricata (L.) Ach., E. mesomorpha Nyl., E. perfragilis Llano, and E. prunastri (L.) Ach., are discussed from the standpoint of taxonomy, distribution, and ecology. The North American distributions of E. divaricata and E. perfragilis are mapped for the first time. A puzzling lichen found on the ground in alpine areas from New Mexico north to Alberta is regarded as an ecological variant of E. divaricata.