On siliceous rocks in natural conditions, once found on railway ballast and on a brick wall in a city.

Belgium: FL.: RRR, Ard.: R.

Luxembourg: - .

France: - .

Lit.: La66: 324-326, NL97: 56, Hellemans & Stappaerts (2009), Lambinon & Sérusiaux (1985a: 86).