The lichen flora of the Nordic countries contains about 2000 species. The last attempt at a flora is the unfinished Lichenographica Scandinavica of T.M. Fries in the 1870s. A number of Nordic lichenologists have now joined forces to produce a complete flora with volumes at yearly intervals.
The only previous attempt to write a flora for the Nordic countries is the unfinished work by Th. M. Fries: Lichenographia Scandinavica (1871-74). With the increasing use of lichens in matters of nature conservation and biodiversity studies additional to the needs of lichenologists, the demand for a modem flora appears obvious and urgent. The editors have, like Fries, attempted to make a scientific flora covering the rich lichen flora of the region which has been regarded as one of the lichenologically best known in the world. They usually only include fungi which form independent thalli with the photobiont (except for this volume). and thus no truly lichenicolous fungi, though the editors have for practical reasons included some borderline-cases, then often as comments in the text, and not as individual entries. However, in some groups such as Calicioid fungi and lichens, non-lichenized species are also treated.
The area covered is Denmark with the Faeroe Islands and Greenland; Finland including Åland; Iceland; Norway with the Arctic Islands including Svalbard, Bjørnøya and Jan Mayen; and Sweden.
The lichen flora of the Arctic islands, including Greenland, is treated rather cursorily since it is not well-known and contains many taxa which are in need of a modem revision outside the scope of this flora. No full description is given on the taxa that are only known from Greenland, but they are mentioned in the keys.
In a number of details the flora follows the presentation in The Lichen Flora of Great Britain and Ireland (Purvis et al. 1992), but includes a considerably different species composition and is essentially based on material from the Nordic countries.
The flora will for practical reasons be published in separate volumes, though preferably so that each volume covers taxonomically related or similar taxa. Because of this it is impossible to present a general key or a glossary before the last volume, and the editors recommend the readers to consult the British lichen flora (Purvis et al. 1992), though this flora covers a different range of species. The treatment of the Nordic flora is entirely based on original studies made on material collected in our region.