KEYS TO THE LICHENS OF ITALY - 38) PSORA (with Romjularia)
Pier Luigi Nimis
Apparatus of images: Andrea Moro - Software and databases: Stefano Martellos

Psora is a subcosmopolitan genus of the Psoraceae with c. 40 species mostly occurring on more or less calcareous soil and rocks (Timdal 1984, 1986). The genus Romjularia has been recently created for R. lurida, which had been switched back and forward between several genera, among which Lecidea, Mycobilimbia and Psora (Timdal 2007); a phylogenetic analysis based on molecular data suggests that the genus is most closely related to a group of genera (including Bryobilimbia, Clauzadea, Farnoldia and Lecidoma) that do not belong to Lecideaceae s.str. (Fryday & al. 2014). This key includes all species of Psora known to occur in Italy (Nimis 2016), plus Romjularia lurida, for a total of 8 species.


Fryday A., Printzen Ch., Ekman S. 2014. Bryobilimbia, a new generic name for Lecidea hypnorum and closely related species. Lichenologist, 46, 1: 25-37.
Nimis P.L. 2016. The Lichens of Italy. A Second Annotated Catalogue. EUT, Trieste, 739 pp.
Timdal E. 1984. The delimitation of Psora (Lecideaceae) and related genera, with notes on some species. Nordic J. Bot., 4: 525-540.
Timdal E. 1986. A revision of Psora (Lecideaceae) in North America. The Bryologist, 89, 4: 253-275.
Timdal E. 2007. Romjularia. In: Nash T.H. III, Gries C., Bungartz F.: Lichen Flora of the Greater Sonoran Desert Region. Vol. 3. Lichens Unlimited, Arizona St. Univ., Tempe, pp. 287-289.

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