Phylogeny of non‐monophyletic Teucrium (Lamiaceae: Ajugoideae): Implications for character evolution and taxonomy

Abstract

Teucrium, with an almost cosmopolitan distribution, comprises about 250 species and is the second ‐ largest genus of subfamily Ajugoideae (Lamiaceae). Phylogenetic studies were conducted using nuclear ribosomal DNA (ITS) and chloroplast (ndhF gene, trnL‐F region) DNA sequence data from 101 taxa to estimate phylogenetic relationships among Teucrium and its closest allies. We conclude that: (1) Teucridium, Spartothamnella and Oncinocalyx are nested within Teucrium, thus rendering the latter paraphyletic; (2) previously proposed taxonomic classification systems for Teucrium mostly are not supported by our phylogenetic results; (3) Rubiteucris and Schnabelia appear to be sister to Teucrium. Our results indicate that, among various morphological characters, the calyx shape is diagnostic for different clades within Teucrium. Based on the cladograms derived in this study, the pattern of karyotype evolution suggests that switches in ploidy level are common in at least two groups. Adaptations to drought stress and the regional establishment of Mediterranean climates obviously facilitated speciation and the spread of the genus. Molecular dating analyses indicate diversification of Teucrium at the middle/late Miocene boundary, correlated with Tertiary climatic and tectonic changes.

Molecular systematics of Caryopteris (Lamiaceae) and its allies with reference to the molecular phylogeny of subfamily Ajugoideae

“…2010; Barrabé & al., 2015;Salmaki & al., 2016) have both segregated and merged genera, resulting in the currently accepted 23 genera: Aegiphila Jacq., Ajuga L., Amasonia L.f., Amethystea L., Caryopteris Bunge, Clerodendrum L., Discretitheca P.D.Cantino, Glossocarya Wall. ex Griff., Hosea Ridl., Kalaharia Baill., Karomia Dop, Monochilus Fisch.…”

“…Although several phylogenetic studies have focused on particular genera of Ajugoideae (Steane & al., 1997(Steane & al., , 1999(Steane & al., , 2004Huang & al., 2008;Yuan & al., 2010;Barrabé & al., 2015;Salmaki & al., 2016), no study has combined intensive sampling of the Caryopteris complex with broad sampling of Ajugoideae as a whole. Steane & al.…”

Untangling the generic boundaries in tribe Marrubieae (Lamiaceae: Lamioideae) using nuclear and plastid DNA sequences

“…We amplified the trnL intron, trnL-trnF intergenic spacer and the rps16 intron as described by Salmaki & al. (2013) and Salmaki & al. (2016), respectively.…”

“…For amplifying the ITS region, trnL intron and trnL-trnF intergenic spacer region and rps16 intron marker from old herbarium specimens, Phusion polymerase (New England Biolabs, Ipswich, Massachusetts, U.S.A.) was used following the modified procedure described by Salmaki & al. (2016).…”

Molecular phylogeny and divergence times of Onosma (Boraginaceae s.s.) based on nrDNA ITS and plastid rpl32‐trnL(UAG) and trnH–psbA sequences

“…Our dating analysis, in agreement with the findings of Cecchi et al (2011), suggests that Onosma s.s. might have experienced a rapid radiation at the Mio-Pliocene boundary (6-5 mya). This period roughly corresponds to the Messinian salinity crisis of the Mediterranean region (Fauquette et al 2006, Jolivet et al 2006, Rouchy and Caruso 2006, which led to an extremely dry climate, which could have favored such a rapid radiation in Onosma as in many other Mediterranean taxa (Fauquette et al 2006, Salmaki et al 2016).…”