Distribution: N - Frl (Tretiach & Hafellner 2000), Ven, TAA (Nascimbene & al. 2022), Lomb, Piem (Morisi & Sereno 1995, Piervittori 2003, Isocrono & al. 2006, 2007), VA (Piervittori & Isocrono 1997, 1999). C - Tosc (Benesperi 2006), Sar (Nöske 2000, Nöske & al. 2000, Rizzi & al. 2011). S - Camp (Aprile & al. 2002), Cal (Puntillo 1996), Si (Caniglia & Grillo 2003, Grillo & Caniglia 2004, 2006).
Description: Thallus leprose, woolly-textured, continuous to cracked, ecorticate, easily separated from the substrate, usually forming extensive, irregularly spreading, 0.3-1 mm thick patches, entirely consisting of bright lemon-yellow, (20-)40-75(-150) µm thick, irregular, soredia-like granules which become paler toward the interior of the thallus. Apothecia and pycnidia unknown. Photobiont chlorococcoid. Spot tests: K- or K+ faintly orange, C-, KC- or KC+ faintly reddish, P-, UV- or UV+ dull orange. Chemistry: calycin, vulpinic acid and sometimes zeorin (minor).
Note: a widespread lichen found in underhangs and crevices of siliceous rocks in shaded, humid situations, limited to areas with high air humidity; widespread throughout the Alps, also occurs in the siliceous mountains of southern Italy and of Sardegna.