Although commonly sterile, Tephromela grumosa is easily recognizable due to coarse blue-grey soredia densely covering almost all the thallus surface. Thallus and young soredia are yellowish. Similar lichens, such as T. pertusarioides and Lecanora pannonica, form discrete soralia and differ in secondary metabolites.
Tephromela grumosa grows on vertical or steeply inclined siliceous rocks and boulders, prefers acidic to slightly basic rocks in open habitats from lowlands to mountains. It can be found on natural rock outcrops, bigger stones in pastures or even anthropogenic substrates, such as gravestones. In central Europe, it is reported rarely probably due to its specific ecology, but might also be overlooked. Scattered all over the Czech Republic.taxonomic classification:
All records: 98, confirmed 82. One click on a selected square displays particular record(s), including their source(s).