Ecology—At the collection site, C. conciliascens grew on mylonitized granite rock in shady place in the subnival belt of Tatra Mts. It was accompanied by Lecanora cenisia Ach.
Geographical distribution—The species is know from Austria (Wunder 1974, Hafellner & Turk 2001), Italy (Nimis 1993) and Turkey (John 1996).
Comments—Caloplaca conciliascens is characterized by a reddish black apothecial disc and brownish black margin. Wunder (1974) treated this taxon in the study on saxicolous species of Caloplaca with black coloured apothecia. The group of lichens is not homogeneous and this particular species has been considered as a member of C. ferruginea group (Wunder 1974, Kärnefelt 1989). Wetmore (1996a) discussed C. conciliascens in his taxonomic treatment of C. siderites group in North and Central America. He concluded that C. conciliascens, C. exsecuta (Nyl.) Dalla Torre & Sarnth., C. conciliascens (Nyl.) H. Olivier, C. litoricola Brodo and C. britzelmayri (Hue) Zahlbr. are probably closely related and form one distinct group characterized by presence of “dark apothecial margin and lecidea green instead of thalloidima green” (Wetmore 1996a).
Caloplaca conciliascens is very similar to C. exsecuta, which is a fairly common species distinguished by a very thin, sometimes almost disappearing thallus, flat to strongly convex apothecia, higher hymenium (65-135 µm) and a hypothecium (50-125 µm), which is always brownish coloured with numerous oil drops and wider spores (5.5-8.0 µm) (Wunder 1974).
Other related species are: C. concilians that differs from C. conciliascens in having abundant algae in the apothecial margin, C. britzelmayri with dirty yellowish apothecium disc, larger spores that occupies calcareous rocks, and C. litoricola, which besides distinctive characters of the apothecia is a maritime species known from western coast of North America (Wetmore 1996a,b). Clauzade & Roux (1985) regarded the taxon as closely related to C. conversa (Kremp.) Jatta. Caloplaca conversa in comparison with C. conciliascens produces smaller apothecia of different anatomy—margins usually lecanorine, with distinct oval cells, never black or greenish coloured (Wunder 1974). The two species differ also due to their chemistry (see Wetmore 1996a).