The thallus is scale-bound, heteromeric, thin, fine-grained, grayish, grayish-yellowish, straw-yellow, yellowish, grayish-greenish or brown; KOH does not turn yellow. Apothecia are small, 0.3-0.8 mm (rarely 1 mm) in diameter, evenly distributed over the thallus or crowded, more or less rounded, sessile, sometimes almost submerged in the thallus. The disk is flat to slightly convex, tan, reddish-brown or brown, glabrous, sometimes in the early stages of development covered with a very thin coating, surrounded by a thin, finely serrated, sometimes slightly powdery, somewhat brighter than the thallus, or straw-yellow thallus edge, sometimes in old apothecies disappearing. The excipient is poorly developed. Hypothecia up to 40 microns high, colorless to yellowish, with large violet-colored grains. Epithets 8.4–11.2 μm in height, strongly or granular, brown or brownish. The hymenial layer is 70-100 microns high, almost colorless or yellowish, from KOH not changing in color, but turning blue from iodine. Paralysis fused, articulate, slightly thickened at the top and slightly colored. Narrow -clavate bags , 75–85 × 14–17 μm, with 8 ellipsoid unicellular spores , 8–15 × 4–7 μm. Pycnoconidia are curved, blunt at the ends, 7-12 × 2-4 microns.
Algae of the genus Protococcus .
On old processed wood and on rotting stumps. It is found absent-mindedly and often in places, especially in the coniferous forest zone.
It occurs in the temperate and tropical zones of Asia , in Australia , Europe , North America , including Mexico , the Arctic zone.
Secondary metabolites are present: atranorin, isosnic acid and neosnic acid, zeorin [1] .
