Distribution: N - Frl (Tretiach & Hafellner 2000), Ven (Nascimbene & al. 2021), Lig (TSB 33559). S - Cal (Lich. Graec. 285: Obermayer 2006, Puntillo 2011).
Description: Thallus crustose, episubstratic, dark orange-yellow, thick, composed by closely packed, granular, up to 0.3 mm wide elements, continuous to cracked-areolate, forming an almost pulvinate crust of small, effigurate to almost granular areoles. Apothecia rare, lecanorine, sessile, 0.3-1.5 mm across, with a yellow to grey-yellow, flat to somewhat convex disc and a thin to thick, entire to crenulate, persistent margin. Proper exciple often visible from the outside; epithecium yellow-brown; hymenium colourless, 55-75 µm high; paraphyses simple or sparingly branched in upper part, cylindrical or with weakly swollen tips, up to 3.5 µm wide; hypothecium colourless. Asci 12-16(-32)-spored, clavate, with an apical dome which is I+ blue only in the internal, lower part, interrupted in the centre by a a paler blue strip, Candelaria-type. Ascospores 1-celled to 1-septate, hyaline, oblong-obtuse, 9-14 x (3-)4.5-5.5(-6.5) µm. Photobiont chlorococcoid. Spot tests: thallus and apothecia K- or K+ reddish-orange, C-, KC-, P-, UV-. Chemistry: calycin, pulvinic acid, pulvinic dilactone and vulpinic acid.
Note: a boreal-montane, poorly understood lichen found on the top of poles and wooden fences, on plant debris and soil, more rarely on rocks in upland areas; certainly more widespread in the Alps. The delimitation of this species is problematic: most of the material distributed in exsiccata belongs to other species, and it is doutbul whether the material called “C. kuusamoensis” by Central and Southern European authors really corresponds to the type material, which in itself resembles a luxuriant C. vitellina growing on mosses (Westberg, in litt.).