Acta Horti Gotob. 17: 236 (1947).
Type locality: Switzerland, Graubünden, Engadin, Zernez, alte Zaunlatten, 1500 m, 16.8.1924, E. Frey s.n. (G - holotype).
Chemistry: Spot tests all negative. No lichen substances.
Thallus: crustose, thin, dark grey to grey-green or grey-brown, or even copper-brown (on exposed substrates), inconspicuous or typically continuous to rimose, or thicker and areolate; areoles to ca. 0.70 mm wide; surface plane to somewhat rugose, matt; margin indeterminate; prothallus lacking; vegetative propagules absent. Apothecia broadly attached to narrowly attached, frequent xxx (Sheard 2010: 98).