Lecanora muralis

Description:

Thallus placodioid (a crust with a lobed, almost foliose margin), pale- to brownish cream, greenish-grey or grey; apothecia with yellow- to grey- or red-brown discs, often crowded and becoming angular. On natural, bird-enriched rocks, and on concrete and other urban substrates; widespread and becoming very common in urban areas, less so in the north and west. On paving slabs often assumed to be discarded and trodden chewing gum

Habitat:

On a granite-stone wall at the Sierra de Guadarrama, close to Madrid

Notes:

Camera Model: NIKON D300. Exposure Time: 1/60 sec. f/3.5 ISO Speed Rating: 200. Focal Length: 90.0 mm. Flash fired