Hiding in plain sight: Integrative analyses uncover a cryptic Salvia species in Europe

Salvia is the most species-rich genus of the family Lamiaceae, currently numbering almost 1000 species. The diagnostic feature of the genus is the unique staminal lever mechanism that allows for specific pollination modes. We encountered an unusual Salvia form in the field, in SE Romania, which resembles S. austriaca but features a radically different lever mechanism. This form proved to be geographically widespread on the Pontic steppe, never occurring in sympatry with S. austriaca. We used an integrative approach, employing morphometric and phylogenomic (RADseq) analyses, to study this unusual form. The taxon's floral morphology proved to be consistently and subtly different from that of S. austriaca, and similarly, Bayesian species delimitation using genome-wide SNP data indicated species-level differences. Our results provide compelling evidence that points toward the discovery of an unrecognized species. This species has been overlooked for centuries, misidentified as S. austriaca, a closely related taxon. The new species differs from S. austriaca in key features of floral structure, habitat preference, and distribution. The potential range of this cryptic species, its pollination biology, ecology, and phylogeography are discussed.

Automated summary

This study used morphometric and phylogenomic analyses and found an overlooked species of Salvia. The new species differs from closely related taxa in floral structure, habitat preference, and distribution.