a1 ABL Herbarium, Gerrit van der Veenstraat 107, NL-3762 XK Soest, The Netherlands. Email: firstname.lastname@example.org
a2 Department of Botany, University of Shahid Beheshti, P. O. Box 1983963113, Tehran, Iran
a3 Botanischer Garten und Botanisches Museum, Freie Universität, Königin-Luise-Straße 6-8, D-14195 Berlin, Germany
The lichen Pyrenula minutissima is described as new to science from the Hyrcanian forests in northern Iran. In addition, three further, essentially tropical, Pyrenula species are reported for the first time from Iran. An identification key is provided for all eight Pyrenula species now known from Iran.
(Accepted December 15 2011)