Syn.: Synalissa symphorea (Ach.) Nyl.

In crevices of hard calcareous rocks, sometimes overgrowing species like Psora lurida, always in natural conditions.

Belgium: Mosan: AR.

Luxembourg: - .

France: Mosan: RRR, Lorr.: RRR.

Lit.: Ertz: 20, La69: 101, NL77: 23, NL84: 17, NL97: 56, John (1990a: 245, 1990b: 225).