The Current Diversity and Distribution of the Simple Thalloid Genus IApopellia/I : Evidence from an Integrative Taxonomic Study

An integrative study of expanded sampling of Apopellia species, including the topotype of Apopellia megaspora, made it possible to clarify the taxonomic position and distribution of the species of the genus. The ITS1-2 and trnL-F sequence data were obtained for 36 molecularly tested specimens, including the topotype Apopellia megaspora, that together with data previously deposited in GenBank, support the treatment of Apopellia as a separate genus and A. alpicola as a distinct species, as well as radically change the idea on the distribution of the species of the genus. It is shown that A. megaspora is an American-Asian species with single records in Europe, whereas A. alpicola is a West-American-Eurasian species widespread in western North America and occurring scattered in Eurasia. Both species occur in the mountains of western North America and south Siberia. A. endiviifolia is widespread in Europe, scattered in Asia and so far not confirmed for America. The expanded sampling of Apopellia spp. allows us to clarify the morphological features of the species of the genus, and microphotographs illustrate the more-important morphological features.