Phylogenomic analyses revealed widely occurring hybridization events across Elsholtzieae (Lamiaceae).

Obtaining a robust phylogeny proves challenging due to the intricate evolutionary history of species, where processes such as hybridization and incomplete lineage sorting can introduce conflicting signals, thereby complicating phylogenetic inference. In this study, we conducted comprehensive sampling of Elsholtzieae, with a particular focus on its largest genus, Elsholtzia. We utilized 503 nuclear loci and complete plastome sequences obtained from 99 whole-genome sequencing datasets to elucidate the interspecific relationships within the Elsholtzieae. Additionally, we explored various sources of conflicts between gene trees and species trees. Fully supported backbone phylogenies were recovered, and the monophyly of Elsholtzia and Keiskea was not supported. Significant gene tree heterogeneity was observed at numerous nodes, particularly regarding the placement of Vuhuangia and the E. densa clade. Further investigations into potential causes of this discordance revealed that incomplete lineage sorting (ILS), coupled with hybridization events, has given rise to substantial gene tree discordance. Several species, represented by multiple samples, exhibited a closer association with geographical distribution rather than following a strictly monophyletic pattern in plastid trees, suggesting chloroplast capture within Elsholtzieae and providing evidence of hybridization. In conclusion, this study provides phylogenomic insights to untangle taxonomic problems in the tribe Elsholtzieae, especially the genus Elsholtzia.

An updated tribal classification of Lamiaceae based on plastome phylogenomics.

BACKGROUND: A robust molecular phylogeny is fundamental for developing a stable classification and providing a solid framework to understand patterns of diversification, historical biogeography, and character evolution. As the sixth largest angiosperm family, Lamiaceae, or the mint family, consitutes a major source of aromatic oil, wood, ornamentals, and culinary and medicinal herbs, making it an exceptionally important group ecologically, ethnobotanically, and floristically. The lack of a reliable phylogenetic framework for this family has thus far hindered broad-scale biogeographic studies and our comprehension of diversification. Although significant progress has been made towards clarifying Lamiaceae relationships during the past three decades, the resolution of a phylogenetic backbone at the tribal level has remained one of the greatest challenges due to limited availability of genetic data. RESULTS: We performed phylogenetic analyses of Lamiaceae to infer relationships at the tribal level using 79 protein-coding plastid genes from 175 accessions representing 170 taxa, 79 genera, and all 12 subfamilies. Both maximum likelihood and Bayesian analyses yielded a more robust phylogenetic hypothesis relative to previous studies and supported the monophyly of all 12 subfamilies, and a classification for 22 tribes, three of which are newly recognized in this study. As a consequence, we propose an updated phylogenetically informed tribal classification for Lamiaceae that is supplemented with a detailed summary of taxonomic history, generic and species diversity, morphology, synapomorphies, and distribution for each subfamily and tribe. CONCLUSIONS: Increased taxon sampling conjoined with phylogenetic analyses based on plastome sequences has provided robust support at both deep and shallow nodes and offers new insights into the phylogenetic relationships among tribes and subfamilies of Lamiaceae. This robust phylogenetic backbone of Lamiaceae will serve as a framework for future studies on mint classification, biogeography, character evolution, and diversification.

Analysis of codon usage bias and evolution in the chloroplast genome of Mesona chinensis Benth.

Mesona chinensis Benth (MCB) is one of the main economic crops in tropical and subtropical areas. To understand the codon usage bias (CUB) in M. chinensis Benth, chloroplast genome is essential to study its genetic law, molecular phylogenetic relationships, and exogenous gene expression. Results showed that the GC content of 53 CDS sequences was 37.95%, and GC1, GC2, and GC3 content were 46.02%, 38.26%, and 29.85%, respectively. The general GC content order was GC1>GC2>GC3. Moreover, the majority of genes had an effective number of codon (ENC) value greater than 40, except ndhE, rps8, and rps18. Correlation analysis results revealed that the GC content was significantly correlated with GC1, GC2, GC3, and ENC. Neutrality plot analysis, ENC-plot analysis, and PR2-plot analysis presented that the CUB of M. chinensis Benth chloroplast genome was mainly affected by mutation and selection. In addition, GGG, GCA, and TCC were found to be the optimal codons. Furthermore, results of cluster analysis and evolutionary tree showed that M. chinensis Benth was closely related to Ocimum basilicum, indicating that there was a certain correlation between the CUB of the chloroplast gene and the genetic relationship of plant species. Overall, the study on the CUB of chloroplast genome laid a basis for genetic modification and phylogenetic research of M. chinensis Benth chloroplast genome.

DNA barcoding of some medicinally important plant species of Lamiaceae family in India.

Several species of the Lamiaceae family are the primary source of bioactive aromatic oils and secondary metabolites, having broader applications in the cosmetics, pharmaceuticals, food, confectionery and liquor industries. Due to the scarcity of raw materials and high costs of this family's economically vital species, its products often adulterated to cater to the market's high demand. The present study provides a DNA based approach for identifying different species of this family. Henceforth, the performance of three already proposed barcode loci (matK, trnH-psbA and trnL) was examined for their PCR amplification and species recognition efficacy on various Lamiaceae species and cultivars using three different approaches such as pairwise genetic distance method, BLASTn and phylogenetic tree based on maximum likelihood (ML) analysis. Results illustrate that among all the DNA barcoding loci, matK locus can accurately and efficiently distinguish all the studied species followed by trnH-psbA and trnL. Present investigation may help diminish the illegal trade and events of adulteration of medicinally important plants species in genus Mentha, Ocimum and Plectranthus. This investigation will also help fulfil the scarcity of sequences of barcode loci of these species in the NCBI database. Apart from providing a molecular level reference for identifying processed herbal products, this technique also offers a convenient method for species identification and germplasm conservation of the Lamiaceae family.

Independent evolution of rosmarinic acid biosynthesis in two sister families under the Lamiids clade of flowering plants.

As a means to maintain their sessile lifestyle amid challenging environments, plants produce an enormous diversity of compounds as chemical defenses against biotic and abiotic insults. The underpinning metabolic pathways that support the biosynthesis of these specialized chemicals in divergent plant species provide a rich arena for understanding the molecular evolution of complex metabolic traits. Rosmarinic acid (RA) is a phenolic natural product first discovered in plants of the mint family (Lamiaceae) and is recognized for its wide range of medicinal properties and potential applications in human dietary and medical interventions. Interestingly, the RA chemotype is present sporadically in multiple taxa of flowering plants as well as some hornworts and ferns, prompting the question whether its biosynthesis arose independently across different lineages. Here we report the elucidation of the RA biosynthetic pathway in Phacelia campanularia (desert bells). This species represents the borage family (Boraginaceae), an RA-producing family closely related to the Lamiaceae within the Lamiids clade. Using a multi-omics approach in combination with functional characterization of candidate genes both in vitro and in vivo, we found that RA biosynthesis in P. campanularia involves specific activities of a BAHD acyltransferase and two cytochrome P450 hydroxylases. Further phylogenetic and comparative structure-function analyses of the P. campanularia RA biosynthetic enzymes clearly indicate that RA biosynthesis has evolved independently at least twice in the Lamiids, an exemplary case of chemotypic convergence through disparate evolutionary trajectories.

Changing Ecological Opportunities Facilitated the Explosive Diversification of New Caledonian Oxera (Lamiaceae).

Phylogenies recurrently demonstrate that oceanic island systems have been home to rapid clade diversification and adaptive radiations. The existence of adaptive radiations posits a central role of natural selection causing ecological divergence and speciation, and some plant radiations have been highlighted as paradigmatic examples of such radiations. However, neutral processes may also drive speciation during clade radiations, with ecological divergence occurring following speciation. Here, we document an exceptionally rapid and unique radiation of Lamiaceae within the New Caledonian biodiversity hotspot. Specifically, we investigated various biological, ecological, and geographical drivers of species diversification within the genus Oxera. We found that Oxera underwent an initial process of rapid cladogenesis likely triggered by a dramatic period of aridity during the early Pliocene. This early diversification of Oxera was associated with an important phase of ecological diversification triggered by significant shifts of pollination syndromes, dispersal modes, and life forms. Finally, recent diversification of Oxera appears to have been further driven by the interplay of allopatry and habitat shifts likely related to climatic oscillations. This suggests that Oxera could be regarded as an adaptive radiation at an early evolutionary stage that has been obscured by more recent joint habitat diversification and neutral geographical processes. Diversification within Oxera has perhaps been triggered by varied ecological and biological drivers acting in a leapfrog pattern, but geographic processes may have been an equally important driver. We suspect that strictly adaptive radiations may be rare in plants and that most events of rapid clade diversification may have involved a mixture of geographical and ecological divergence.

Computer-Aided Chemotaxonomy and Bioprospecting Study of Diterpenes of the Lamiaceae Family.

Lamiaceae is one of the largest families of angiosperms and is classified into 12 subfamilies that are composed of 295 genera and 7775 species. It presents a variety of secondary metabolites such as diterpenes that are commonly found in their species, and some of them are known to be chemotaxonomic markers. The aim of this work was to construct a database of diterpenes and to use it to perform a chemotaxonomic analysis among the subfamilies of Lamiaceae, using molecular descriptors and self-organizing maps (SOMs). The 4115 different diterpenes corresponding to 6386 botanical occurrences, which are distributed in eight subfamilies, 66 genera, 639 different species and 4880 geographical locations, were added to SistematX. Molecular descriptors of diterpenes and their respective botanical occurrences were used to generate the SOMs. In all obtained maps, a match rate higher than 80% was observed, demonstrating a separation of the Lamiaceae subfamilies, corroborating with the morphological and molecular data proposed by Li et al. Therefore, through this chemotaxonomic study, we can predict the localization of a diterpene in a subfamily and assist in the search for secondary metabolites with specific structural characteristics, such as compounds with potential biological activity.

Structural characterization of vegetative organs of the endangered Brazilian native species Hesperozygis ringens (Benth.) Epling.

The aim of this study was to describe the structural characterization of Hesperozygis ringens (Benth.) Epling vegetative organs. For this purpose, leaves, stems and roots of the endangered Lamiaceae were collected from a population located in Santo Antão, Santa Maria municipality, Rio Grande do Sul, Brazil. Results demonstrated that the H. ringens leaf blade presents glandular and non-glandular trichomes as well as two morphs of diallelocytic stomata, which are usually found above the epidermis level. The petiole is concave on ventral face and convex on its dorsal face, containing glandular and non-glandular trichomes as well as stomata in the epidermis. These types of trichomes were also detected in the stem. In addition, the presence of intercellular spaces within the organ is highlighted. Stomata above epidermis level also occurred in the stem. Phenolic idioblasts were found in the cortical region of plant root and deposit of lipophilic substance was observed in phloem cells. Great amount of apparently two different crystals were detected in all organs. Information obtained in this study provides knowledge about the characterizationof H. ringens, which may be used to distinguish characters of taxa and can help understand the species survival in its occurrence sites.

Terpene Esters from Natural Products: Synthesis and Evaluation of Cytotoxic Activity.

Natural steroids and triterpenes such as b-sitosterol, stigmasterol, lupeol, ursolic and betulinic acids were transformed into its hexanoic and oleic esters, to evaluate the influence of chemical modification towards the cytotoxic activities against tumor cells. The derivatives were evaluated against five tumor cell lines [OVCAR-8 (ovarian carcinoma); SF-295 (glioblastoma); HCT-116 (colon adenocarcinoma); HL-60 (leukemia); and PC-3 (prostate carcinoma)] and the results showed only betulinic acid hexyl ester exhibits cytotoxic potential activity.

Molecular characterization of patchouli (Pogostemon spp) germplasm.

Patchouli [Pogostemon cablin (Blanco) Benth.] is an aromatic, herbaceous plant belonging to the Lamiaceae family native to Southeast Asia. Its leaves produce an essential oil regularly used by the perfume and cosmetics industries. However, since patchouli from the Philippines and India were described and named Pogostemon patchouli, there has been a divergence in the identity of these species. The objective of the current study was to study the genetic diversity of patchouli accessions in the Active Germplasm Bank of Universidade Federal de Sergipe using microsatellite and inter simple sequence repeat markers. The results of both types of molecular markers showed that there are two well-defined clusters of accessions that harbor exclusive alleles. It was observed that these two clusters are genetically distant, suggesting that they belong to two different species. Based on the results, two accessions were classified as Pogostemon heyneanus and the remaining accessions were classified as P. cablin.

Untangling reticulate evolutionary relationships among New World and Hawaiian mints (Stachydeae, Lamiaceae).

The phenomenon of polyploidy and hybridization usually results in novel genetic combinations, leading to complex, reticulate evolution and incongruence among gene trees, which in turn may show different phylogenetic histories than the inherent species tree. The largest tribe within the subfamily Lamioideae (Lamiaceae), Stachydeae, which includes the globally distributed Stachys, and one of the largest Hawaiian angiosperm radiations, the endemic mints, is a widespread and taxonomically challenging lineage displaying a wide spectrum of morphological and chromosomal diversity. Previous molecular phylogenetic studies have showed that while the Hawaiian mints group with Mexican-South American Stachys based on chloroplast DNA sequence data, nuclear ribosomal DNA (nrDNA) sequences suggest that they are most closely related to temperate North American Stachys. Here, we have utilized five independently inherited, low-copy nuclear loci, and a variety of phylogenetic methods, including multi-locus coalescence-based tree reconstructions, to provide insight into the complex origins and evolutionary relationships between the New World Stachys and the Hawaiian mints. Our results demonstrate incongruence between individual gene trees, grouping the Hawaiian mints with both temperate North American and Meso-South American Stachys clades. However, our multi-locus coalescence tree is concurrent with previous nrDNA results placing them within the temperate North American Stachys clade. Our results point toward a possible allopolyploid hybrid origin of the Hawaiian mints arising from temperate North American and Meso-South American ancestors, as well as a reticulate origin for South American Stachys. As such, our study is another significant step toward further understanding the putative parentage and the potential influence of hybridization and incomplete lineage sorting in giving rise to this insular plant lineage, which following colonization underwent rapid morphological and ecological diversification.

Evaluation of hemostatic and anti-inflammatory activities of extracts from different Lagochilus species in experimental animals: comparison of different extractives and sources.

Different members of Lagochilus genus have been used in folkloric medicine to treat hemorrhages and inflammation. However, only a few species of them have received scientific attention supporting their efficacy. Here, the hemostatic and antiinflammatory activities of five Lagochilus species were determined and compared by using in vivo assays. The results showed that the extracts of Lagochilus lanatonodus and Lagochilus diacanthophyllus showed better hemostatic activities among five species. The high doses of L. lanatonodus extracts were able to shorten the values of thrombin time, activated partial thromboplastin time and prothrombin time in a rat model. Moreover, the extracts of L. lanatonodus and L. diacanthophyllus showed strong inhibitory effects on the acute phase of inflammation in both xylene-induced ear edema mouse model and carrageenan-induced paw edema rat model. In parallel, the treatment of these extracts modulated the expressions of those inflammatory parameters, that is, nitric oxide, prostaglandin E2 , inducible nitric oxide synthase, malondialdehyde and superoxide dismutase. L. lanatonodus and L. diacanthophyllus showed better hemostatic and antiinflammatory activities in several test models: these results therefore supported the folkloric utilization. L. lanatonodus was found to be the most active Lagochilus species.

[Analysis of varieties and standards of labiatae medicinal plants used in Tibetan medicine].

In this paper, an analysis was made on the varieties and standards of labiatae medicinal plants used in Tibetan medicine. The results showed 71 species of labiatae plants in 21 genera (including varieties) recorded in relevant literatures, involving 44 varieties of medicinal materials. Specifically, seven species (9.9%) were intersected with traditional Chinese medicines (TCM), 19 varieties (43%) were recorded in Chinese medicinal material standards at all levels, and 27 species (38%) were source plants. In Tibetan medicine standards and literatures, there are great differences between Tibetan names and translated Chinese names and among varieties of source plants. Apart from a few of varieties intersected with traditional Chinese medicines had complete standards and regulations in Chinese Pharmacopoeia, most of species only had characters, microscopic, physical and chemical identifications in Standards Issued by Ministry of Health-Tibetan Medicine, Tibetan Medicine Standard and local standards. Therefore, the Tibetan medicinal material variety-source specification and quality standard system shall be promoted on the basis of literatures research, investigations for resources and current applications and modern pharmaceutical studies.

Volatile compounds in Thymus sect. Teucrioides (Lamiaceae): intraspecific and interspecific diversity, chemotaxonomic significance and exploitation potential.

Thymus sect. Teucrioides comprises three species, namely, T. hartvigii, T. leucospermus, and T. teucrioides, distributed in Greece and Albania. The volatile constituents of all species of the section were obtained by hydrodistillation and investigated by GC-FID and GC/MS analyses. Twenty populations were sampled and a total of 103 compounds were identified, representing 98.0-99.9% of the oil compositions. The oils were mainly characterized by high contents of monoterpene hydrocarbons (42.7-92.4%), with the exception of three oils for which oxygenated monoterpenes were the dominating constituents, viz., that of T. hartvigii ssp. macrocalyx, with linalool as main compound (89.2±0.5%), and those of T. hartvigii ssp. hartvigii and of one population of T. teucrioides ssp. candilicus, containing thymol as major component (46.4±3.1 and 38.2±3.9%, resp.). The most common compound in the oils of the 20 populations of the section was p-cymene. Considerable variation was detected within and among populations, and seven chemotypes were distinguished, i.e., p-cymene, linalool, p-cymene/thymol, p-cymene/γ-terpinene, p-cymene/borneol, p-cymene/γ-terpinene/borneol, and p-cymene/linalool chemotypes. Different chemotypes may exist in the same population. Multivariate statistical analyses enabled the segregation of the oils within Thymus sect. Teucrioides into two groups, one consisting of the three subspecies of T. teucrioides and the second comprising the species T. hartvigii and T. leucospermus. A linalool-rich chemotype, unique within the section, distinguished the oil of T. hartvigii ssp. macrocalyx from all other oils. The high oil content of p-cymene and the preference for serpentine substrates render T. teucrioides species promising for future exploitation.

Identification of two chemotypes of Pogostemon cablin (Blanco) Benth. through DNA barcodes.

Pogostemon cablin (Blanco) Benth. is an important medicinal plant in Traditional Chinese Medicine (TCM). Because of differences in the chemical composition, this species has been classified into two major chemotypes, i. e. the patchouliol-type and the pogostone-type; however, no quick and effective method is presently available for the precise identification of these two chemotypes. DNA barcoding, using a standardized DNA fragment, is a promising molecular diagnostic method for species identification. We have established a reliable and quick method for the identification of the P. cablin chemotypes. Of five potential barcodes [rbcL, psbA-trnH, rpoB, ITS (internal transcibed spacer), and ndhJ], tested among 103 samples, ITS was the best candidate, as comparative studies between patchouliol-type and pogostone-type P. cablin revealed that ITS had more variable regions among these five barcodes. We suggest that ITS can serve as the most suitable barcode for differentiating between the chemotypes of P. cablin.

Rapid characterization of non-volatile phenolic compounds reveals the reliable chemical markers for authentication of traditional Chinese medicine Xiang-ru among confusing Elsholtzia species.

The aerial parts of Mosla chinensis Maxim. and Mosla chinensis cv. 'Jiangxiangru' (MCJ) are widely utilized in traditional Chinese medicine (TCM), known collectively as Xiang-ru. However, due to clinical effectiveness concerns and frequent misidentification, the original plants have increasingly been substituted by various species within the genera Elsholtzia and Mosla. The challenge in distinguishing between these genera arises from their similar morphological and metabolic profiles. To address this issue, our study introduced a rapid method for metabolic characterization, employing high-resolution mass spectrometry-based metabolomics. Through detailed biosynthetic and chemometric analyses, we pinpointed five phenolic compounds-salviaflaside, cynaroside, scutellarein-7-O-D-glucoside, rutin, and vicenin-2-among 203 identified compounds, as reliable chemical markers for distinguishing Xiang-ru from closely related Elsholtzia species. This methodology holds promise for broad application in the analysis of plant aerial parts, especially in verifying the authenticity of aromatic traditional medicinal plants. Our findings underscore the importance of non-volatile compounds as dependable chemical markers in the authentication process of aromatic traditional medicinal plants.

Diversification of plant species in arid Northwest China: species-level phylogeographical history of Lagochilus Bunge ex Bentham (Lamiaceae).

Lagochilus occurs in the arid zones across temperate steppe and desert regions of Northwest China. Cooling with strong dessication in the Pleistocene, along with rapid uplift of mountain ranges peripheral to the Qinghai-Tibet Plateau, appear to have had major impacts on the genetic structure of the flora. To understand the evolutionary history of Lagochilus and the divergence related to these past shifts of habitats among these regions, we sequenced the plastid intergenic spacers, psbA-trnH and trnS-trnG from populations throughout the known distributions of ten species of the genus. We investigated species-level phylogeographical patterns within Lagochilus. Phylogenetic trees were constructed using Neighbor-joining and Bayesian inference. The divergence times of major lineages were estimated with BEAST and IMa. Genetic structure and demographic history were inferred by AMOVA, neutrality tests, mismatch distribution, and Bayesian skyline plot analyses. The results showed that most chloroplast haplotypes were species-specific, and that the phylogeny of Lagochilus is geographically structured. The estimated Bayesian chronology and IMa suggested that the main divergence events for species between major eastern and western portions of the Chinese desert occurred at the Plio-/Pleistocene boundary (ca. 2.1-2.8 Ma ago), and likely coinciding with the formation of these deserts in Northwest China. The regional demographic expansions, in the western region at ca. 0.39 Ma, and in the eastern at ca. 0.06 Ma, or across all regions at ca. 0.26 Ma, showed the response to aridification accompanied by cooling of the Pleistocene sharply increased aridity in the Chinese deserts, which reflects a major influence of geologic and climatic events on the evolution of species of Lagochilus. We suggest that diversification is most likely the result of the past fragmentation due to aridification; the expansion of the range of species along with the deserts was an adaptation to dry and cold environments during the Quaternary.

Molecular phylogeny of tribe Stachydeae (Lamiaceae subfamily Lamioideae).

Although tribe Stachydeae (Lamiaceae) is considered monophyletic, relationships within the tribe are still poorly understood. The complexity of Stachydeae includes paraphyletic genera, considerable morphological plasticity, a range of ploidy levels, and presumably frequent natural hybridization. We performed parsimony and Bayesian phylogenetic analyses of nuclear (ribosomal ITS) and plastid (trnL intron, trnL-trnF spacer, rps16 intron) DNA sequence data from a taxonomically and geographically broad sampling of the tribe to identify major evolutionary lineages and to test taxonomic hypotheses within this largest of all lamioid tribes. We included 143 accessions corresponding to 121 species, representing both Old and New World species, and all 12 recognized genera of tribe Stachydeae. Both nuclear and plastid data corroborate monophyly of the tribe, with Melittis as sister to all remaining Stachydeae. For the latter well-supported clade, we suggest the phylogenetic name Eurystachys. Within Eurystachys, although monophyly is supported by both nuclear and plastid data for several named and unnamed groups, the majority of recognized taxa appear to be para- or polyphyletic. The taxon compositions of most subclades are congruent between the plastid and nuclear tree topologies, whereas their relative phylogenetic placements are often not. This level of plastid-nuclear incongruence suggests considerable impact of hybridization in the evolution of Stachydeae.

Phylogeny and biogeography of New World Stachydeae (Lamiaceae) with emphasis on the origin and diversification of Hawaiian and South American taxa.

Due to its unique geological history and isolated location, the Hawaiian Archipelago provides an ideal setting for studies on biogeography, phylogeny and population biology. Species richness in these islands has been attributed to unique colonization events. The Hawaiian mints comprising of three endemic genera represent one of the largest radiations in the island. Previous studies have shown the Hawaiian mints to be nested within the dry-fruited Stachys, probably resulting from one or more hybridization events. Stachydeae, the largest tribe in the subfamily Lamioideae (Lamiaceae), is a taxonomically complex and widespread lineage exhibiting remarkable chromosomal diversity. In this paper we attempted at untangling the relationships between the New World and Hawaiian mint taxa, as well as investigate the origin and diversification of the mints in the New World. There seem to have been at least two independent migration events of Stachys to the New World during the Middle to Late Miocene and towards the beginning of the Pliocene, respectively. Results indicate incongruence between the rDNA and cpDNA phylogenies suggesting a reticulate, New World origin for the Hawaiian mints, although dispersal to Hawaii appears to have happened only once during the Pliocene. South American Stachys diversified from their Mesoamerican relatives around Late Pliocene and may also have arisen from similar reticulate events indicated by their intercalating position among the Mesoamerican Stachys species. Further insights into the phylogenetic relationships between the New World mints may be gathered through the study of low copy nuclear loci.

A preliminary phylogeny of the genus Cunila D. Royen ex L. (Lamiaceae) based on ITS rDNA and trnL-F regions.

Cunila species are aromatic and medicinal plants commonly employed in folk medicine. This genus is distributed in North America and in southern South America. The species that occur in southern South America are classified into three botanical sections: Incanae, Incisae and Spicatae. The present study uses a phylogenetic approach to study the genetic relationship among the South and North American Cunila species, aiming to test the monophyly of the genus in its traditional circumscription. The results based on sequencing from nuclear (ITS rDNA) and chloroplast (trnL-F) sets did not agree with the traditional circumscription of the genus. These data, based on maximum parsimony, maximum likelihood and Bayesian analyses, point to the non-monophyletic status of Cunila, since the genus was separated into three segregated clades: (1) A South American subshrub clade formed by the species of the botanical section Spicatae, (2) a South American shrub clade that includes the species of the botanical sections Incanae and Incisae, and (3) a North American Cunila clade.