Lichenology is the branch of mycology that studies the lichens, symbiotic organisms made up by the association of a microscopical alga with a filamentous fungus.
The taxonomy of lichens was first intensively investigated by the Swedish botanist Erik Acharius (1757-1819), who is therefore sometimes named the "father of lichenology". Acharius was a student of Carolus Linnaeus. Some of his more important works on the subject, which marked the beginning of lichenology as a discipline, are:
⇒ Lichenographiae Suecia prodromus (1798)
⇒ Methodus lichenum (1803)
⇒ Lichenographia universalis (1810)
⇒ Synopsis methodica lichenum (1814)
Later lichenologists include the American botanist Edward Tuckerman and the Russian evolutionary biologist Konstantin Merezhkovsky.