Nordic Lichen Flora Volume 4 – Parmeliaceae
The lichen flora of the Nordic countries, containing about 2000 species, is regarded as one of the best known in the world. Lichenological research of the region has been continuous since the days of Erik Acharius (1757–1819), the ”father of lichenology”, but it is a sad fact that there is no modern flora treatment of the region's impressive lichen flora, the last attempt in the 1870s being that o