Eranthis Salisb. (Ranunculaceae) in South Siberia: Insights into Phylogeography and Taxonomy.

Eranthis Salisb. (Ranunculaceae) is a herbaceous plant genus, including few species disjunctively distributed throughout the temperate zone from Southeastern Europe to Eastern Asia. Until recently, only Eranthis sibirica DC. was known in South Siberia, being considered endemic and tertiary relict. Not long ago, Eranthis tanhoensis Erst was also described in Siberia. We report here a reconstruction of the phylogenetic relationships between the Siberian Eranthis species based on nuclear (ITS) and plastid (trnL + trnL-trnF + trnH-psbA) DNA. The phylogeographic structure of Siberian Eranthis is distinguished by the presence of the two "eastern" and "western" supergroups, which most likely formed as a result of disjunction caused by active mountain uplifts during the late Neogene–early Quaternary and subsequent progressive Pleistocene cooling. The eastern supergroup combines lineage I, containing populations from the eastern Khamar-Daban Ridge, the Eastern Sayan Mountains, and the Tannu-Ola Ridge, and lineage II containing western Khamar-Daban populations. The western supergroup includes only lineage III, containing Western Sayan populations. Our data clearly show that E. tanhoensis is nested in the E. sibirica clade, thereby indicating that its description as a separate species is unjustified, as it compromises the monophyletic status of E. sibirica. Therefore, we suggest here to consider E. tanhoensis as a synonym of E. sibirica. [ABSTRACT FROM AUTHOR]