AUTHOR=Zhao Fei , Wu Yi-Wen , Drew Bryan T. , Yao Gang , Chen Ya-Ping , Cai Jie , Liu En-De , Li Bo , Xiang Chun-Lei 

TITLE=Systematic Placement of the Enigmatic Southeast Asian Genus Paralamium and an Updated Phylogeny of Tribe Pogostemoneae (Lamiaceae Subfamily Lamioideae)

JOURNAL=Frontiers in Plant Science

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2021.646133

DOI=10.3389/fpls.2021.646133

ISSN=1664-462X

ABSTRACT=<p><italic>Paralamium</italic> (Lamiaceae) is a monotypic genus within the subfamily Lamioideae and has a sporadic distribution in subtropical mountains of southeast Asia. Although recent studies have greatly improved our understanding of generic relationships within Lamioideae, the second most species-rich subfamily of Lamiaceae, the systematic position of <italic>Paralamium</italic> within the subfamily remains unclear. In this study, we investigate the phylogenetic placement of the genus using three datasets: (1) a 69,276 bp plastome alignment of Lamiaceae; (2) a five chloroplast DNA region dataset of tribe Pogostemoneae, and (3) a nuclear ribosomal internal transcribed spacer region dataset of Pogostemoneae. These analyses demonstrate that <italic>Paralamium</italic> is a member of Pogostemoneae and sister to the monotypic genus <italic>Craniotome</italic>. In addition, generic-level phylogenetic relationships within Pogostemoneae are also discussed, and a dichotomous key for genera within Pogostemoneae is provided.</p>