On siliceous rocks in natural and artificial habitats, rarely on wood.

Belgium: Fl.: RRR, Camp: RR, Mosan: RR, Ard.: AR, Lorr.: RR.

Luxembourg: Ard.: R, Lorr.: RR.

France: Ard.: RR. Most probably overlooked.

Lit.: NL77: 23, NL84: 18, NL87: 23, NL92: 164, Sé: 144, Coppins & van den Boom (1995: 89).