Description: Thallus crustose, episubstratic, white to pale grey, rather thick, continuous to rimose-areolate, with scattered, isidia-like, short-cylindrical, sometimes apically widened, usually simple (rarely with a few branches) to 1.5 mm high and c 0.5 mm wide papillae. Apothecia not known. Photobiont chlorococcoid. Spot tests: thallus and medulla K-, C-, KC- or KC+ very pale yellow (medulla only), P-, UV-; medulla I+ pink to pinkish brown, without a bitter taste. Chemistry: unidentified fatty acids.
Note: on base- or mineral-rich rocks in rainy areas near and above treeline, up to the nival belt in the Alps; probably restricted to the Alps and the northern Apennines in Italy.
Growth form: Crustose
Photobiont: green algae other than Trentepohlia
Reproductive strategy: mainly asexual, by isidia, or isidia-like structures (e.g. schizidia)