Phylogenetics of Salvia subgenus Calosphace. Extensive sectional non-monophyly in Salvia subgenus Calosphace (Lamiaceae) unravelled by nuclear and plastid DNA sequence data

Salvia subgenus Calosphace (Lamiaceae, Lamiales) is a highly diverse clade endemic to the Neotropics. The phylogenetic relationships of Calosphace have been previously investigated using DNA sequences of nuclear ITS region and plastid psbA-trnH intergenic spacer, but the resulting trees lack resolution and support for many clades. The present paper reassesses the phylogenetic relationships of subgenus Calosphace, including a broader taxon sampling (with a special focus on the monotypic sections) and an additional plastid marker (the trnL-trnF region). Our results show increased resolution and overall patterns of support and recover 10 main clades. Additionally, within the most inclusive of these clades, the core Calosphace clade, 14 new clades were identified. Twelve sections were found to be monophyletic, and most of the monotypic sections were placed within core Calosphace. Previous taxonomic proposals, including Epling’s sectional structure, are discussed as a reference for subsequent studies aimed at a phylogenetically sound infrageneric classification of Salvia. A biogeographic reconstruction identified at least nine migrations to South America from Mexican and Central american lineages, in agreement with previous suggestions of multiple origins of South American Calosphace diversity