Systematic placement of Elsholtzia griffithii (Nepetoideae, Lamiaceae), a new record from China

Abstract

Elsholtzia griffithii, the first record in Guangxi Province, China, is described and illustrated in detail. We provided the most updated phylogeny of Elsholtzia based on two nuclear ribosomal DNA regions (ITS, ETS) to resolve the phylogenetic placement of this species. Our study reveals that E. griffithii is most closely related to E. cyprianii but differs from it by having linear bracts ≥ 4 mm and distinctively longer than flowers (vs. bracts ≤ 3 mm in E. cyprianii) and calyx teeth unequal, two anterior lobes shorter than three posterior lobes (vs. five lobes equal in length). In addition, monophyly of Elsholtzia was strongly supported and three clades were recognized, whereas all sections and series were not recovered as monophyletic, indicating that reclassification is needed at higher taxonomic levels.