Current knowledge about lichens of the Leningrad region (LR) and St. Petersburg is based on considerable amount of data (ca 70000 records), including field data, publications (ca 300), herbarium
collections (ca 15000 records) and archival materials amassed over the past 250 years. In total 1034
species (914 lichenized, 90 lichenicolous and 30 saprobic fungi) are known from the area. Of them,
564 species were recorded in St. Petersburg. Western part of LR is clearly richer in species than eastern: 904 taxa were found in the west, while only 637 species in the east. Altogether 171 (17%) species
are known from the only locality. The territories to the north and west from LR have quite rich and
well-investigated lichen floras: 959 species are known from the southern part of Republic of Karelia,
1166 from Estonia, more than 1300 from southern Finland. Known lichen diversity of southern and
eastern neighbours is lower due to less active investigations and high anthropogenic pressure: 356,
299, ca 280 taxa are known from Novgorod, Pskov and Vologda regions respectively. Nowadays the
lichens of LR are quite well-studied and we don’t expect the number of species to increase significantly, but the lichenicolous fungi definitely are not enough investigated.