Lepraria Cf. incana
Here is briefly described a still undetermined taxon (at our level):
Thallus crustose, thick, markedly cracked, deep crevices determining areoles, slightly convex, pavement-like, powdery owing to minute elongate granules, suggesting globose isidia, colour highly variable, pale blue, dark blue, blue-greyish, grey-greenish, grey-purple, celadon, etc., often with brown-rusty spots and covered with microalgae. Fruiting bodies have not been observed. C-, K-, KC-, P-, but it remains difficult to conclude since the thallus is hydrophobic. Typically found below siliceous rocks or in slate quarries in places completely protected from direct light and rain, often together with Psilolechia lucida. N.B. This taxon is rather similar to Tephromela grumosa found in more lit areas but this species is fertile and has soredia. This undetermined taxon probably has been collected as Lepraria incana s.l. but it still remains to demonstrate that it corresponds to Lepraria incana s.s.