Erik Acharius, Linnaeus last pupil and accounted as "The father of lichenology", was born 250 years ago, on the 10th of October 1757. After graduating in Uppsala and taking his medical degree in Lund, he eventually settled in Vadstena, where he worked as a provincial doctor and chief physician at the hospital for veneral diseases. At the age of 36 he wrote his first lichenological work and then continued to work relentlessly on lichen systematics until his death in 1819, expanding the knowledge of this group enormously. He described many new species and genera which still are recognized, and his lichen system was recognized worldwidely. After his death a series of unfortunate events led to that his valuable lichen herbarium was sold to Helsinki. The majority of the herbarium, though, was donated to Lund university in 1843, and we are proud to preserve this in the Biological museums today.