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.

Juan Chen;Sijin Zeng;Linya Zeng;Khang Sinh Nguyen;Jiawei Yan;Hua Liu;Nianhe Xia

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;Institute of Ecology and Biological Resources,Vietnam Academy of Science and Technology,18 Hoang Quoc Viet,Hanoi,Vietnam;Graduate University of Science and Technology,Vietnam Academy of Science and Technology,Hanoi,Vietnam;Department of Horticulture and Landscape Architecture,Zhongkai University of Agriculture and Engineering,510225,Guangzhou,People's Republic of China

植物多样性（英文）

[1]Juan Chen;Sijin Zeng;Linya Zeng;Khang Sinh Nguyen;Jiawei Yan;Hua Liu;Nianhe Xia-.Parahellenia,a new genus segregated from Hellenia(Costaceae)based on phylogenetic and morphological evidence)[J].植物多样性（英文）,2022(04):389-405

Parahellenia,Hellenia,Costaceae,Costus,Plastid,paraphyletic,paraphyly,bracts,labellum

new,genus,segregated,from,phylogenetic,morphological,evidence,Previous,studies,recognized,three,major,lineages,family,South,American,Asian,However,within,has,been,shown,monophyletic,its,morphology,not,studied,carefully,Therefore,complete,plastid,genomes,species,were,obtained,monophyly,was,tested,through,four,different,datasets,this,study,phylogenomic,analyses,revealed,that,strongly,supported,Two,clades,recovered,namely,subclade,Phylogenetic,enlarged,taxon,sampling,using,two,chloroplast,markers,trnK,intron,trnL,spacer,confirmed,Meanwhile,suggested,members,remaining,many,characters,including,inflorescences,stigma,axillary,buds,floral,tubes,According,present,molecular,latter,described,combinations,made,identification,keys,also,provided

0.491554