Key to Danish species of Perichaena Fr.
|1||Fruitbodies open irregularly. Sporocarps or elongated plasmodiocarps.||P. vermicularis (Schwein.) Rostaf.|
|1'||Fruitbodies open by a distinct lid. Sporocarps, often closely aggregated.||2|
|2 (1)||Sporocarps ± spherical to cushion-shaped. Lid marked as a wavy equatorial line.||P. corticalis (Batsch) Rostaf.|
|2'||Sporocarps flattened, closely aggregated and often with angular outline from mutual pressure. Lid marked as a straight line.||P. depressa Lib.|