Tephromela atra (Huds.) Hafellner var. calcarea (Jetta) Clauzade & Roux

    This variety is very similar to the canonical type Tephromela atra var. atra , but the apothecia usually are crowded and cover the whole thallus. The main difference is related to its habitat: on dense calcareous rocks near or on Aspicilia calcarea (parasitic?). The thallus is often more brownish than that of the type (especially on flat surfaces rich in nitrates) and its areolas are less warty, the apothecia are often arranged in small tight groups and occupy almost the entire thallus. Very nitrophilous variety, often parasitized near the sea by Diploschistes caesioplumbeus..