Caloplaca arnoldii (Wedd.) Zahlbr. ex Ginzb.

A locally common species, currently included in the genus Calogaya. It is characterized by yellow-orange, small thallus with marginal lobes. In shady conditions, however, the lobes may be completely absent. It is a saxicolous lichen, which can be found on basic silicates or limestone rocks, especially on overhangs. It also often grows on anthropogenic substrates, such as stones or concrete in the walls of castle ruins. It occurs, more or less, throughout the entire Czech Republic. Moreover, many of the reports of C. saxicola from this territory probably refer to C. arnoldii. At the present, the meaning of the name C. saxicola is unclear and we recommend not to use it.

Ascomycota → Lecanoromycetes → Teloschistales → Teloschistaceae → Caloplaca