Corticolous, most frequent on dry sides of old trees (Populus, Quercus, Salix, etc.) in valleys, also present and locally abundant on Hedera "trunks" climbing over sheltered, calcareous rocks.

Belgium: Fl.: RRR (†<1900), Brab.: RR, Mosan: AR, Ard.: R.

Luxembourg: Ard.: RRR, Lorr.: AR.

France: Boul.: RRR, Pic.: RRR, Lorr.: R.

Lit.: Boul.: 71, Di: 180-181, Ho: 139, 170, 595, L2: 96-97, NL84: 16, NL97: 52.