This grey crustose Rhizocarpon with black apothecia is probably overlooked in central Europe due to its similarity to the common species of Porpidia and Lecidea. From similar Rhizocarpon species, it is distinguished by a high content of norstictic acid. R. suomiense also contains norstictic acid as the main metabolite but has two larger spores in asci (Ihlen 2004).
In Europe, the species is the most abundant in southern Scandinavia (Ihlen 2004) but is certainly present elsewhere, too. It is surprising that it is absent from the list of the lichens of the Alps (Nimis et al. 2018) and from the flora of Germany (Wirth et al. 2013). In the Czech Republic, it has been recorded in the Křivoklát region (protected area Týřov) and from lower elevations of the Šumava Mts (Čertova stráň). It grows on neutral to acidic siliceous rocks here, such as spilite and gneiss, in half-shaded habitats in open forests. The lichen obviously does not have specific requirements on biotopes or microhabitats, so it might be expected to be found at more localities.
Literature: Ihlen P.G. (2004): Taxonomy of the non-yellow species of Rhizocarpon (Rhizocarpaceae, lichenized Ascomycota) in the Nordic countries, with hyaline and muriform ascospores. – Mycological Research 108: 533–570. 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. Wirth V., Hauck M. & Schultz M. (2013): Die Flechten Deutschlands. – Ulmer, Stuttgart.taxonomic classification:
Ascomycota → Lecanoromycetes → Rhizocarpales → Rhizocarpaceae → Rhizocarpon
All records: 4, confirmed 4. One click on a selected square displays particular record(s), including their source(s).