Molecular phylogenetics of Hymenocrater and allies (Lamiaceae): New insights from nrITS, plastid trnL intron and trnL-F intergenic spacer DNA sequences

28 June 2017

Serpooshan, Fariba; Jamzad, Ziba; Nejadsattari, Taher; Mehregan, Iraj

Assumptions about the phylogenetic relationships of Hymenocrater and closely related genera were tested using nrITS and plastid trnL intron and trnL-F intergenic spacer DNA sequences datasets. Here we present a phylogenetic analysis based on the sequence data of 62 species belonging to Hymenocrater, Lophanthus, Marmoritis and Nepeta along with representatives of the rest Nepetinae using maximum parsimony and Bayesian inference. All our results confirm the monophyly of Nepetinae and division of this subtribe into two main clades one of which includes Drepanocaryum, Hymenocrater, Nepeta, Lophanthus and Marmoritis and the other includes Agastache, Glechoma, Meehania, Schizonepeta, Lallemantia, Cedronella and Dracocephalum.
According to our phylogenetic analysis the genus Nepeta is nonmonophyletic. The genera Hymenocrater, Lophanthus, Marmoritis, Drepanocaryum and Nepeta, all are grouped in one clade. The morphological symplesiomorphic traits among these four taxa are: Calyx tube 15 nerved, two lipped, the throat oblique to straight; the corolla two lipped; the two upper stamens longer than the two lowers, included or exerted from the corolla; thecae divergent. In accordance with morphological evidence and regarding to the number of taxa examined and centers of diversity of the genera, here we propose inclusion of Hymenocrater in Nepeta and recognize a few older names of the rest genera as Nepeta. The genus Drepanocaryum is recognized as a sister genus to Nepeta. New combinations and synonyms are introduced.