Syn.: L. muralis var. versicolor (Pers.) Tuck., Protoparmeliopsis muralis (Schreb.) M. Choisy, Placodium saxicolum (Pollich) Körb.

Saxicolous, on calcareous, natural outcrops in nitrophilous conditions, but most common on walls, roofs and concrete, rarely on lignum or at the base of trees covered by dust, incl. in highly polluted areas.

Belgium: CC.

Luxembourg: CC.

France: CC.

Lit.: Ca: 105, Di: 127-128, Ho: 154, Qu: 91-92, VGH: 114, Sansen & Deronde (1990).