Circinaria hoffmanniana (S. Ekman & Fröberg ex R. Sant.) A. Nordin

Lichen with a very similar distribution and ecological requirements as C. contorta s. str. Until recently, both taxa were merged together, or differentiated at the level of variety or (more often) as a subspecies. Circinaria hoffmanniana differs from C. contorta s. str. by at least slightly brown (grey-brown) continuous thallus.

Ascomycota → Lecanoromycetes → Pertusariales → Megasporaceae → Circinaria → Circinaria contorta