Seventeen species of the lichen genus Peltigera, exclusive of the P. canina group, are accepted from Norway. Their morphology, chemistry, ecology, and distribution in Norway are presented, and a key to the species is provided. Peltigera retifoveata is reported as new to Norway and a new species, P. sp. 1, which belongs to the P. aphthosa group, is treated but not formally described.
Different morphotypes of P. aphthosa, P. malacea, and P. neopolydactyla and different chemotypes of P. aphthosa, P. elisabethae, P. horizontalis, P. malacea, P. neopolydactyla, P. scabrosa, and P. sp. 1 are described. Correlations between several morphotypes and chemotypes are shown, but these are not treated as taxonomic units, although they probably are biological species.
Phototype pairs in P. aphthosa, P. britannica, and P. venosa are described, and the close relationship between the two first mentioned and P. malacea is pointed out.
