Picture taken on the 18th February 2007 at Forat del Vent, Cerdanyola, Collserola, Barcelona, on vertical shalty rocks, in fissures, 300 m. altitude.
Common lichen, sometimes considered as a pure variety of Diploschistes scruposus but with a very different habitat.Very large distribion in Europa and Catalonia. Growing on chalk (Nuria) but also on silicious schists (Collserola).
Saxicolous, crustose thallus, white-greyish, irregular, relatively creating large patches, apothecia urceolate, becoming large, disc dark with white pruina.