Methodus, Sectio prior (Stockholmiæ): 4 (1803).

Basionym: Byssus incana L., Spec. Plant. 2: 1169 (1753).

Chemistry: Divaricatic acid (nordivaricatic acid in variable amounts +; divaric acid, divaricatinic acid +) +; zeorin (in variable amounts) +; gyrophoric acid (in variable amounts, mostly in traces) -+ (lecanoric acid -+); atranorin (in variable amounts, mostly in traces)-+ (Leuckert et al. 1995: 247).

Ecology: On bark and silicious rock.

Distribution type: Data lacking.

Taxonomy: Lepraria crassissima, which was formerly included here, is now accepted (Hafellner & Türk 2016: 90).