Dendrographa latebrarum (Ach.) Ertz & Tehler

    Thallus diffuse and inconspicuous, most often without prothallus, grey-pink, pale dull grey, pale grey-purplish, dull whitish covered with large sugglobose and squishy clusters, 5-10 cm diam., possibly merging to build a thick and cottony cushion covering the thallus whole surface, surface concolourous but often dull white due to abrasion, this cushion is made of hyphae surrounding the photobiont (Trentepohlia) and its surface appears (under magnification lens) spiky due to minute dark branches in all directions. Apothecia and pycnidia unknown. Thallus and cushions: C-, K-, KC-, Pd-, UV+ white-blue. Rare, growing in shaded cracks of rocks or under humid siliceous overhangs. N.B. Often associated to Chrysothrix chlorina to shape the Leprarietum chlorinae. N.B. The other species belonging to this distinctive habitat have positive chemical spot tests, except Schismatomma umbrinum that is more brownish and has a well delimited dark brown prothallus.*