Identity and relationships of Sempervivum tectorum (Crassulaceae) in the Rhine Gorge area

A genetic analysis of Sempervivum tectorum (Crassulaceae) reveals that populations in the Rhine Gorge area form a distinct and homogeneous group, separate from those in the Massif Central, Alps, and Pyrenees. The study suggests this disjunct distribution likely reflects remnants of a once-wider range during Quaternary glaciation. Researchers used genotyping-by-sequencing on 52 accessions across the species' range to reconstruct phylogenetic relationships, finding the Rhine Gorge material is most closely related to the Massif Central clade. Taxonomic recognition for the Rhine Gorge group was dismissed due to morphological and nomenclatural reasons.

Fabritzek, A. G., & Kadereit, J. W. (2018). Identity and relationships of Sempervivum tectorum (Crassulaceae) in the Rhine Gorge area. Willdenowia, 48(3), 405. https://doi.org/10.3372/wi.48.48310