Resolving the Veratrum in northern Fennoscandia by targeted sequencing

The genus Veratrum comprises approximately 25 species from temperate and arctic North America and Eurasia. In Europe, Veratrum is mainly distributed in mountainous areas of Central and Southern Europe but is also locally abundant in coastal areas of northeastern Finnmark, Norway. The species name for the Veratrum in Finnmark has been disputed and several names have been used. This includes the names used for the Central European plants, V. album and V. lobelianum, and various subspecies of both. The aim of this study was to place the Veratrum in Finnmark in a phylogenetic context and evaluate which name should be applied. The Veratrum in Finnmark has not previously been studied using molecular methods and its relationship to other populations of Veratrum has therefore stayed unknown. Previous phylogenetic trees based on Sanger sequences of the ITS region have not had sufficient resolution to resolve the relationships within Veratrum. Therefore, a target capture approach was applied, using the Angiosperms353 probe set to obtain a multi-locus data set. The phylogenetic analysis was done with a coalescent-based approach resulting in a multispecies coalescent species tree. The distribution of Veratrum is reflected in the phylogeny and reveals that the plants in Finnmark are closely related to plants in Northern Finland and Russia. This clade of Northern European Veratrum resolves as a distinct genetic variant and represents a separate taxon from the plants in Central Europe. The name V. misae is proposed for the Northern European plants.