Similar to Caloplaca cerina s. lat., but with a scurfy, green-grey thallus, apothecia with thick, grey, somewhat flexuose thalline margins and a plane, often green, pruinose disk, and different habitat preference. K reactions as for C. cerina. The ascospores appear to be slightly longer than those of C. cerina, but it is not clear whether this is a reliable diagnostic character for GB populations.
According to Šoun et al. (2011), both this species and Caloplaca cerina are aggegates of cryptic taxa. GB collections need molecular analysis to confirm their identity.
Scattered throughout Great Britain with no obvious distibution pattern, but present in both montane and maritime habitats. There is a single record from SW Ireland. BLS map here (as Caloplaca cerina var. chloroleuca).
Overgrowing mosses and dead vascular plants on calcareous soil, rarely extending onto limestone or calcareous schistose and serpentine rock.