Picture taken on the 26th January 2008 at Cal Tet, Prat de Llobregat, corticolous, on Genista sp, indicating the presence of sulphur dioxide and certain level of pollution.
Crustose lichen very common in certain cities and polluted areas, grey-green thallus, thick, areolate, granular-sorediate, sometimes forming large crusts. Apothecia present, 1 mm diameter, green yellow discs, marginal thallus covered by granules.
It is becoming one of the commonest lichens in Europe due to sulphure dioxide pollution.
Be careful not to confuse it with Lecanora expallens.
Molt interessant el fet d'invertir els termes, podent determinar la presència de determinats compostos donada la presència de determinades espècies de liquens. Molt bona la captura i molt interessant l'explicació.