Umbilicaria subpolyphylla Oxner: the correct name for U. iberica Sancho & Krzewicka and its bipolar distribution pattern

Abstract

AbstractThe Umbilicaria polyphylla aggregate (U. polyphylla (L.) Baumg., U. subpolyphylla Oxner and U. iberica Sancho & Krzewicka) is discussed based on morphological, chemical and molecular data. Umbilicaria iberica is proposed to be a later synonym of U. subpolyphylla. The constructed nrITS + mtLSU phylogeny, which includes specimens with wide geographical ranges, shows that both U. polyphylla and U. subpolyphylla are monophyletic and closely related. Both species have the same type of thalloconidia and identical secondary metabolites. Umbilicaria subpolyphylla has prominent phenotypic differences when compared to U. polyphylla including the monophyllous thallus with a dull upper surface and an elevated, slightly wrinkled centre, often covered with white pruina, and a medulla of the ‘U. havaasii’ type. Phylogenetic evidence for the bipolar distribution of both U. polyphylla and U. subpolyphylla is provided. Sympatric speciation in one region followed by long-distance dispersal seems to be the most plausible phylogeographical explanation for the observed patterns. Umbilicaria subpolyphylla is found in southern temperate-subtropical (Mediterranean) mountains, at least in Europe.