Biogeographical research on European species of the lichen genus Physconia

Abstract Aim The (world) distribution of the European species of Physconia Poelt (Lichenes: Physciaceae) except Ph. distorta (With.) J. R. Laundon and Ph. americana Essl.] was investigated. The study was complemented by data on the ecological behaviour of the species. Location The location of the study is the whole world with a local emphasis on Europe. Methods The geographical distribution of the lichen species under consideration was investigated from collection data of herbaria and field studies in a databank. Additional data were taken from existing literature and critically considered. Distribution maps were created with ArcView GIS. The distribution patterns are expressed as three‐dimensional areal formulas, regarding zonal distribution, altitudinal range and oceanity of the species distributions, using the method of Meusel et al. (1965 ). Results The distribution patterns of the ten Physconia taxa considered are represented in detailed maps and expressed as three‐dimensional areal formulas. The ecological behaviour was discussed. Physconia muscigena and Ph. perisidiosa are species of bipolar distribution type, the other species are holarctic types. Physconia detersa and Ph. enteroxantha occur in both Eurasia and North America, the remaining species (Ph.grisea ssp. grisea, Ph. grisea ssp. lilacina, Ph. petraea, Ph. servitii, Ph. subpulverulenta and Ph.venusta) are pure Old world taxa with a much more limited distribution.The majority of the European Physconia taxa are distributed meridionally to submeridionally and occur preferentially in suboceanic areas. Main conclusions Some of the species under consideration have a wide distribution, nevertheless they show clear affinities to ecological conditions that influence their distribution patterns. A number of species show not only zonal and regional restrictions, but also affinities to the western climatic type. The Mediterranean is the centre of diversity of the genus Physconia in Europe.