Pier Luigi Nims
Apparatus of images: Andrea Moro - Software and databases: Stefano Martellos

This genus of the Verrucariaceae consists of c. 20 species worldwide, growing on soil, detritus, mosses and algal or lichen crusts, rarely directly on rock. Placidiopsis differs from the closely related Catapyrenium, which has the same type of upper cortex, in having septate ascospores and lacking pycnidia. The distinction between the two genera has been confirmed by molecular data (Prieto & al. 2010, 2012). The genus has been monographed by Breuss (1996). This is a key to the 7 species known to occur in Italy (Nimis 2016).

Breuss O. 1996. Revision der Flechtengattung Placidiopsis (Verrucariaceae). Öst. Z. Pilzk., 5: 65-94.
Nimis P.L. 2016. The lichens of Italy. A second annotated catalogue. EUT, Trieste, 740 pp.
Prieto M, Martı́nez I., Aragón G., Otálora M.A.G., Lutzoni F. 2010. Phylogenetic study of Catapyrenium s.str. (Verrucariaceae, lichen-forming Ascomycota) and related genus Placidiopsis. Mycologia, 102, 2: 291-304.
Prieto M., Martinez I., Aragón G., Gueidan C., Lutzoni F. 2012. Molecular phylogeny of Heteroplacidium, Placidium, and related catapyrenioid genera (Verrucariaceae, lichen-forming Ascomycota). Am. J. Bot., 99, 1: 23-35.

Project Dryades, Department of Life Sciences, University of Trieste - CC BY-SA 4.0