Data from: Molecular variation and phylogeography within European Isothecium alopecuroides and Pseudisothecium myosuroides (Bryophyta, Lembophyllaceae)

<p><span>Earlier studies on <em>Isothecium</em> s.l. suggested potential interchange of genetic material between species that are nowadays known to belong to separate genera. In this study, we analyze the molecular variation in three molecular markers (nuclear <em>gdp</em>; mitochondrial <em>nad</em>5; and plastid <em>trn</em>G) in a wide selection of <em>Isothecium</em> <em>alopecuroides</em> and <em>Pseudisothecium</em> <em>myosuroides</em> specimens to infer whether this exchange of genetic material is frequent. In addition, we explore the phylogeographic structure of these two species in Europe. Our results show repeated genetic interchange for the nuclear and mitochondrial markers in both species, with intergeneric hybridization as the most probable explanation. The genetic lineages found indicate a complex biogeographical history for <em>I</em>. <em>alopecuroides</em>, including both postglacial immigration from different glacial refugia and developing haplotypes potentially adapted to cold climates. As for <em>P</em>. <em>myosuroides</em>, genetic variants could either indicate a postglacial immigration history or adaptation to oceanic conditions. Further studies including a larger set of more variable molecular markers could help to reach final conclusions on the results here presented.</span></p>