Lichens of Finland is based on the two recent guidebooks: Suomen jäkäläopas (2011) and Suomen rupijäkälät (2015). In total, 212 genera and 748 species, subspecies, or varieties are presented in detail.

In the introduction topics such as lichen characters, taxonomy, habitats, and threatened taxa are discussed. Also, an overview of lichen research in Finland is provided. The detailed treatment of taxa includes genus and species descriptions as well as habitat data and distribution. Common synonyms and threat status are given. Each taxon is illustrated with a colour photograph, and distribution maps are given. An updated checklist of Finnish lichens, lichenicolous fungi, and some lichen-like fungi, altogether 1952 taxa, is provided.

This book is intended for professionals and nature enthusiasts alike. It was published for the 8th International Association for Lichenology Symposium, Helsinki, August 2016, and celebrates the lichenologists and the long tradition of lichenology in Finland.