Die Flechtengattung Caloplaca in Groenland. 1987. (Medd. om Groenland, Bioscience 25). 18 Fig. 52 S. Lex8vo. Paper bd.

A total of 43 species and two species of unclear affinity is described and discussed. Details are given about their ecology and th edistribution of nine species is mapped. The taxonomy of some species-aggregates, including Caloplaca pyracea coll. and several blackfruited saxicolous forms, is considered still unclear. A diagnostic key to all taxa is presented. One species and three varieties are described as new: Caloplaca psoricida, C. citrina var. soropelta, C. jemtlandicavar. cerinosora, C. lithophila var. elaeophora (with oil paraphyses).Some previously differentiated species growing on different substrates are united: Caloplaca stillicidiorum with C. cerina, and C. cinnamomeawith C. ammiospila. Variation in morphology and colour is discussed with special emphasis on the impact of the arctic environment. In several species, e.g. Caloplaca exsecuta and C. tiroliensis, a significant blackening of the apothecium due to anatomical and chemical changes is described.