Ethnobotany, biochemistry and pharmacology of Minthostachys (Lamiaceae)

Aims of the studyThe South American mint genus Minthostachys is of great importance in the Andes as a medicinal, aromatic, culinary and commercial essential oil plant. After decades of taxonomic confusion and virtual indeterminability of specimens, new systematic and taxonomic work has been conducted in recent years. The present paper attempts to summarize the state of knowledge about Minthostachys with a focus on ethnobotany, analyses of essential oil content and pharmacology, to identify the currently accepted species names for the plants examined in these previous studies, and to assess where additional research is needed.Materials and methodsAll available studies on Minthostachys were obtained and evaluated. Herbaria were contacted to identify voucher specimens cited in the respective publications.Results and conclusionsThe great majority of published studies was conducted on a single species, Argentinean Minthostachys verticillata. In contrast, the most widely distributed and well-known species (Minthostachys mollis) as well as several locally important and intensively used species (e.g., Minthostachys acutifolia) have received disproportionately little attention, and virtually nothing is known about the local endemics among the 17 species currently recognized. In many cases, however, it is difficult to relate the results to taxonomic entities due to the lack of voucher specimens. Future research efforts should especially be directed at studying the chemistry and potential for use of several common but so far neglected species of the central and northern Andes, at disentangling environmental and genetic influences on essential oil composition, at prerequisites for cultivation, and at the pharmacological basis of the most important traditional uses. Because of the morphological complexity of the genus, future researchers are urged to deposit voucher specimens of the plants used in their studies to facilitate species identification and to make the results more comparable and reproducible.