On hard calcareous rocks, in dry, sunny and nitrophilous conditions, sometimes parasitic on Verrucaria, also on sandstone rocks and on concrete of gravestones.

Belgium: Mar.: R, Fl.: R, Camp.: R, Brab.: RR, Mosan: AC, Ard.: RRR, Lorr.: RRR.

Luxembourg: Lorr.: RRR.

France: Mar.: RR, Boul.: RRR, Mosan: RRR, Lorr.: RR.

Lit.: Boul.: 67, Ertz: 19, L12: 80-81, Ma: 163-166, NL93: 42, Zwaenepoel et al. (1994: 37) [in most references as C. coronata].