The first Acharius Medal was made by the Royal Swedish Mint for the Royal Swedish Academy of Science in 1846, although the medal's original purpose has not been recorded.  In its 1990 meeting at Regensburg, the International Association for Lichenology (IAL) resolved that it would simultaneously honor professional achievement, and commemorate Erik Acharius (recognized as the "Father of Lichenology"), by presenting a medal in his name. 
Since the Swedish Mint still had the dies for the 1846 medal, the IAL arranged for new medals to be made. The first of the new medals were awarded in that same year at the association's congress in Båstad, Sweden.
Acharius Medals have been presented in 1992 (thirteen recipients), 1994 (four recipients), 1996 (three recipients), 2000 (three recipients), 2002 (one recipient), 2003 (one recipient), 2004 (three recipients), 2006 (one recipient), 2008 (three recipients), 2010 (two recipients), and 2012 (two recipients).
The medal is silver, with Acharius' profile on one side and the recipient's name on the other.
- "Plant Science Bulletin, Volume 39, Issue 1, 1993".
- "International Association for Lichenology (IAL)".
- International Lichenological Newsletter, volume 25, number 3 (December 1992), pp 12-13
- Ingvar Kärnefelt, David J. Galloway, Arne Thell (2007). Lichenological contributions in honour of David Galloway. Cramer in der Gebrüder Borntraeger Verlagsbuchhandlung. p. 103. ISBN 3-443-58074-2.