Maximum likelihood (ML) tree of Pogostemon and its relatives inferred from the combined dataset (including nrITS, matK, psbA-trnH, rbcL, rps16, trnL-F). Bootstrap (BS) value in ML analysis and posterior probility (PP) in Bayesian inference (BI) is indicated on the left and right of slanting bar associated with phylogenetic node, respectively. Dashes denote that the phylogenetic node associated was not supported or the BS value is < 50% in ML anlaysis or PP < 0.50 in BI. The crown node of Pogostemon is show by the arrowhead.