Syn.: Physcia grisea (Lam.) Zahlbr.

Corticolous on old roadside trees and in orchards (mainly Fraxinus, Populus, Tilia and Ulmus, also on Malus, Pyrus, etc.), rare on concrete or on old calcareous walls, always in rather nitrophilous conditions.

Belgium: Mar.: C, Fl.: C, Brab.: C, elsewhere: AC-AR.

Luxembourg: Ard.: R, Lorr.: AC.

France: Mar.: RR, Boul.: R, Pic.: R, Mosan, Ard., Lorr.: AC-AR.

Lit.: Boul.: 72, Ca: 164-165, Ho: 220, La66: 479-480, Qu: 122-123, VGH: 114, WS: 52, 103.