A timeframe for mint evolution: Towards a better understanding of trait evolution and historical biogeography in Lamiaceae
Rose, Jeffrey; Xiang, Chin-Lei; Sytsma, Kenneth; Drew, Bryan (2022), A timeframe for mint evolution: Towards a better understanding of trait evolution and historical biogeography in Lamiaceae, Dryad, Dataset, https://doi.org/10.5061/dryad.zw3r2288z
The mint family (Lamiaceae) is one of the largest and most economically important families of flowering plants. Despite focused study on relationships within subclades, higher-level relationships have been understudied. Moreover, the herbaceous habit of much of the family has resulted in a poor fossil record and has hampered estimates of divergence times. Using a new dataset of five plastid loci from 178 Lamiaceae representing all subfamilies and nearly all tribes, we clarify major infrafamilial relationships and present a robust set of divergence times. We use this phylogenetic hypothesis as a platform to test prior hypotheses regarding the historical biogeography and evolution of major traits within the family. We confirm the placement of subfamily Nepetoideae, show continued uncertainty in the placement of subfamilies Ajugoideae and Premnoideae, and highlight extreme discordance with recent results from nuclear data. Lamiaceae originated during the Late Cretaceous as a woody plant with a nutlet fruit and four stamens, probably in Southeast Asia. Most subfamilies diverged during the Eocene, perhaps facilitated by climatic cooling. Our results provide a valuable set of secondary dates for Lamiaceae and highlight the need for focused study of subfamilies Callicarpoideae and Viticoideae. Our results also provide several hypotheses regarding trait or range-dependent diversification.