Picture taken on the 14th August 2007 at Querigut, Ariège, France, among mosses, vertical position, siliceous substratum, under Fagus sylvatica, 1.300 m. altitude.
A relatively frquent lichen in sheltered woodland.
Foliose lichen, thallus not very big up to 10 cm. diameter, blue-grey when hydrated, lobes about 1 cm wide with edges covered by numerous bluish grey soredia, very determining of this species.