Plant Diversity ›› 2022, Vol. 44 ›› Issue (04): 389-405.DOI: 10.1016/j.pld.2022.02.001

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Parahellenia, a new genus segregated from Hellenia (Costaceae) based on phylogenetic and morphological evidence

Juan Chena, Sijin Zenga, Linya Zenga, Khang Sinh Nguyenc,d, Jiawei Yana,b, Hua Liua, Nianhe Xiaa   

  1. a Guangdong Provincial Key Laboratory of Applied Botany/Guangdong Provincial Key Laboratory of Digital Botanical Garden, South China Botanical Garden, Chinese Academy of Sciences, 510650, Guangzhou, People's Republic of China;
    b Department of Horticulture and Landscape Architecture, Zhongkai University of Agriculture and Engineering, 510225, Guangzhou, People's Republic of China;
    c Institute of Ecology and Biological Resources, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Hanoi, Vietnam;
    d Graduate University of Science and Technology, Vietnam Academy of Science and Technology, Hanoi, Vietnam
  • Received:2021-11-12 Revised:2022-01-25 Online:2022-07-25 Published:2022-08-13
  • Contact: Nianhe Xia,
  • Supported by:
    The authors are very grateful to the staff of Qixingkeng Nature Reserve, Mr. Chaoyi Deng, Mr. Jianghua Huang, Mr. Jianjun Ou, Mr. Renbing Zhu, Mr. Shinian Lu and Mr. Yunfeng Huang for their help during field trips, Dr. Alex Dalberg Poulsen, Dr. Kalu B. Meeking and Mr. Yushi Ye for sharing images, Mr. Dave Skinner for sharing many images of Parahellenia species and Gideon's key to Tapeinochilos, Prof. Khoon Meng Wong for comments and corrections on a manuscript version of this paper, Mr. Dinghan Cui for preparing the illustration and the anonymous reviewers for their comments on the paper. The following herbaria are acknowledged for access to their collections: E, GXMG, GXMI, HITBC, IBK, IBSC, L, KUN, K, P, PE and US. We would also like to thank Chinese Virtual Herbarium (CVH,, National Specimen Information Infrastructure (NSII,, Global Biodiversity Information Facility (GBIF, and Plants of the World Online ( for providing digital images of specimens. This research was funded by the National Natural Science Foundation of China (Grant no. 32070223) and the Biological Resources Programme, Chinese Academy of Sciences (Grant no. KFJ-BRP-017-19).

Abstract: Previous studies recognized three major lineages of the family Costaceae: a South American clade, an Asian clade and a Costus clade. However, the genus Hellenia within the Asian clade has been shown to be non-monophyletic and its morphology has not been studied carefully. Therefore, the complete plastid genomes of Hellenia species were obtained and the monophyly of Hellenia was tested through four different datasets in this study. Plastid phylogenomic analyses of Costaceae revealed that Hellenia is strongly supported as paraphyletic. Two major clades are recovered, namely the Hellenia s.s. subclade and the Parahellenia subclade. Phylogenetic analyses based on an enlarged taxon sampling of the Asian clade using a two chloroplast markers dataset (trnK intron and trnL-F spacer) confirmed the paraphyly of Hellenia. Meanwhile, morphological analyses suggested that members of the Parahellenia subclade differ from the remaining Hellenia species in many characters including inflorescences, bracts, stigma, axillary buds, floral tubes and labellum. According to the present molecular and morphological evidence, the latter subclade is recognized as a new genus, Parahellenia. Two new species are described, four new combinations are made, and identification keys are also provided.

Key words: Molecular phylogenomics, New genus, New species, Cheilocostus