New to North America. An arctic-temperate, somewhat continental species previously known from northern and middle Europe, Ural, south-east Siberia, and Japan.

Contains protolichesteric and rangiformic acids.

The following specimens are included in C. odontella with some doubt: CENTRAL PACIFIC COAST DISTRICT: Talkeetna Mts: Independence Mine. ALASKA RANGE DISTRICT: Denali Highway: Mile 28. CENTRAL YUKON RIVER DISTRICT: Steese Highway: Cleary Summit.

These specimens differ from the typical C. odontella in having a more flattened thallus in parts up to 3 mm wide, in pseudocyphellae occurring exclusively on the underside (in odontella partly also along the margins on the upper surface), and in the red colour, which in normal odontella appears only at the base, spreading over most of the under surface. According to SANTESSON (personal communication) this may be an extreme form of odontella or possibly a different taxon. More material is needed before the question can be settled.