Relationships within Timmia, especially within T. austriaca Hedw. (Musci, Timmiaceae)

Introduction Within the moss genus Timmia, three or four sections have been suggested based on morphology. Earlier studies conflicted in suggesting that T. austriaca Hedw. either displays limited phylogeographical structure includes large molecular variation with potential for geographical structure.Methods Relationships within Timmia were inferred from nuclear 26S and plastid atpB–rbcL trnL–trnF. New sequences generated 64 specimens of austriaca. For other species, came primarily earlier GenBank.Key results two main, well-supported lineages. austriaca, arctic subarctic resolved a small-lineage sister to all specimens.Conclusions Recognition is suggested: sect. (syn. Timmiaurea Brassard; syn. Sphaerocarpa Y.Jia & Yang Liu bis) Norvegica Brassard. fossils, including deposited at least 3 Myr BP northernmost North America under milder climate than presently area. It theorised plants small lineage evolved adaptations survive only cold conditions, when Arctic was gradually cooling. disperses easily, because numerous temperate region samples studied included no representatives northern lineage, restricted distribution this resulted adaptation environments. In situ survival Fennoscandia during Late Glacial Maximum, as previously theorised, deemed unlikely due glacial erosion submergence areas result isostatic depression.