Molecular systematics and stamen diversity of Salvia in East Asia

Salvia is the largest genus within Lamiaceae, with about 980 species currently recognized. East Asia, with approx. 100 species, is one of the three major biodiversity centres of Salvia. However, relationships within this lineage remain unclear, and the staminal lever mechanism, which may represent a key innovation within the genus, has been understudied.

Flower morphology of Salvia sonchifolia
Flower morphology of Salvia sonchifolia with emphasis on fully fertile posterior thecae. Photo: Hu et al.

By using of six DNA markers and morphological evidence, Hu et al. puts EA Salvia species in the newly defined subgenus Glutinaria and divides them into eight sections. The authors find six distinct stamen types and suggest stamen with fertile posterior thecae is plesiomorphic. Stamen type has evolved in parallel within the EA Salvia. All the infrageneric classification mainly based on staminal structure is untenable. The study provides a basis for further research on taxonomy and speciation of EA Salvia.

Reference List

Hu, G.-X., Takano, A., Drew, B. T., Liu, E.-D., Soltis, D. E., Soltis, P. S., … Xiang, C.-L. (2018). Phylogeny and staminal evolution of Salvia (Lamiaceae, Nepetoideae) in East Asia. Annals of Botany, 122(4), 649–668. https://doi.org/10.1093/aob/mcy104