Syn.: B. byssoides (L.) Gaertn.

On peaty or humus-rich soil, or directly on soil or siliceous stones or rocks, usually in recently disturbed places.

Belgium: Fl.: RR (†<1900), Camp.: RR (†1894), Brab.: AR→RRR, Mosan: R (†<1900), Ard.: AC, Lorr.: AR.

Luxembourg: Ard.: AC, Lorr.: AR.

France: Ard.: R.

A distinct chemical strain, possibly without any taxonomical value, is sometimes distinguished as var. callianthus (Lettau) Anders [syn.: B. callianthus Lettau]. It is known from Belgium: Ard. (1965) and Luxembourg: Ard. (2007).

Lit.: L6: 140, La66: 300-307, Kuborn & Diederich (2008).