The genus Placopsis, in the Trapeliaceae, includes c. 60 species, mostly early colonisers of rock surfaces and bare soil, such as recently deglaciated areas, and has the highest diversity in the Southern Hemisphere, especially in subantarctic regions. Although having a green algal primary photobiont, Placopsis-species also have cyanobacteria in cephalodia, a character missing in the closely related genus Trapelia. For further details see Schmitt & al. (2003) and Resl & al. (2015). This small key includes the two European species, one of which is known also for Italy (Nimis 2016), the other one reported from the Austrian Alps (Nimis & al. 2018) and to be looked for in the most humid parts of the Italian Alps.

References

Nimis P.L. 2016. The lichens of Italy. A second annotated catalogue. EUT, Trieste, 740 pp.
Nimis P.L., Hafellner J., Roux C., Clerc P., Mayrhofer H., Martellos S., Bilovitz P.O. (2018) The lichens of the Alps - an annotated checklist. MycoKeys, 31: 1-634.
Resl P., Schneider K., Westberg M., Printzen C., Palice Z., Thor G., Fryday A., Mayrhofer H., Spribille T. 2015. Diagnostics for a troubled backbone: testing topological hypotheses of trapelioid lichenized fungi in a large-scale phylogeny of Ostropomycetidae (Lecanoromycetes). Fungal Divers., 73: 239-258.
Schmitt I., Lumbsch H.T., Søchting U. 2003. Phylogeny of the lichen genus Placopsis and its allies based on Bayesian analyses of nuclear and mitochondrial sequences. Mycologia, 95, 5: 827-835.

Last modified: June, 16, 2003

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