Taiwania 64(4): 367-395, 2019 DOI: 10.6165/tai.2019.64.367 Updating Taiwanese pteridophyte checklist: a new phylogenetic classification Taiwan Pteridophyte Group (TPG): Li-Yaung KUO1,2,#, Tian-Chuan HSU3,#, Yi-Shan CHAO4, Wei-Ting LIOU5, Ho-Ming CHANG6, Cheng-Wei CHEN3, Yao-Moan HUANG3, Fay-Wei LI7,8, Yu-Fang HUANG9, Wen SHAO10, Pi-Fong LU11, Chien-Wen CHEN3, Yi-Han CHANG3,*, Wen-Liang CHIOU3,12,* 1. Institute of Molecular & Cellular Biology, National Tsing Hua University, Hsinchu 30013, Taiwan. 2. Bioresource Conservation Research Center, College of Life Science, National Tsing Hua University, Hsinchu 30013, Taiwan. 3. Taiwan Forestry Research Institute, No. 53, Nanhai Rd., Taipei City 10066, Taiwan. 4. Department of Biomedical Science and Environmental Biology, Kaohsiung Medical University, No. 100, Shih-Chuan 1st Rd., Kaohsiung City 80708, Taiwan. 5. Experimental Forest, College of Bio-Resources and Agriculture, National Taiwan University, No.12, Sec. 1, Qianshan Rd., Zhushan Township, Nantou County 55750, Taiwan. 6. Endemic Species Research Institute, No.1, Minsheng E. Rd., Jiji Township, Nantou County 552, Taiwan. 7. Boyce Thompson Institute, 533 Tower Rd., Ithaca, New York 14853, USA. 8. Plant Biology Section, Cornell University, 236 Tower Rd., Ithaca, New York 14850, USA. 9. Department of Biology Sciences, National Sun Yat-sen University, No. 70, Lien-Hai Rd., Kaohsiung City 80424, Taiwan. 10. Shanghai Chenshan Botanical Garden, intersection of Chenta Rd. and Shetiankun Rd., Songjiang, Shanghai 201602, China. 11. Taiwan Society of Plant Systematics, No. 1, Sec. 4, Roosevelt Rd., Taipei City 10617, Taiwan. 12. Dr. Cecilia Koo Botanic Conservation and Environmental Protection Foundation/Conservation Center, No. 31, Tongsing Rd., Gaoshu Township, Pingtung County 906, Taiwan. #The authors contributed equally. *Corresponding authors: YHC’s phone: 886-8-8861812#106; email: [email protected]; WLC’s phone: 886-2-2303-9978#2908; email: [email protected] (Manuscript received 25 December 2018; accepted 9 July 2019; online published 25 August 2019) ABSTRACT: Ferns and lycophytes of Taiwan display an extraordinarily high diversity. Despite the detailed species documentation, the pteridophyte flora of Taiwan as a whole has never been organized into a phylogenetic framework. Here we provide an updated, phylogeny-based checklist that includes a total of 824 (infra)species taxa, of which eleven are first recorded. In addition, lectotypification of Phlegmariurus salvinioides and new combinations of 25 taxa were made in this study. Our classification scheme is based on the most recent phylogenetic evidence, and for all taxon names accepted here, we provide their best corresponding names in Taiwanese Mandarin. Our appendix and the online file also supply other details, such as synonyms, for the Taiwanese pteridophytes in order to track their nomenclatural changes from the previous floristic documentations. Finally, a discussion group for our community-Taiwan Pteridophyte Group (TPG)- is established online. This platform will allow more users to follow further updates of TPG or to provide any comments on new versions of Taiwan pteridophyte checklist. KEY WORDS: Checklist, Conservation assessment, Fern, Lycophyte, PPG, Pteridophyte, Taiwan, TPG. INTRODUCTION Chao, 2019; Chen et al., 2019). Despite the detailed species documentation, the Ferns and lycophytes (= pteridophytes) of Taiwan pteridophyte flora of Taiwan as a whole has never been display an extraordinarily high diversity (Fig. 1) that, in organized into a phylogenetic framework that aims to terms of the pteridophyte species number, represents one reflect natural relationships of pteridophyte species by of the top five most speciose insular floras in the world ordering them with the generic and higher-levels. (Kreft et al., 2010). Knapp, in a recent work, “Fern and Advanced by insights from molecular phylogenetics, Fern Allies of Taiwan” (Knapp, 2011, 2013, Knapp and systems for pteridophyte classification have evolved Hsu, 2017) summarizes a total of 801 species and lower rapidly during the past decades, and experienced drastic taxa (including unidentified taxa), representing a near changes at different taxonomic levels (Smith et al., 2006; 20%-increase in the taxon number that had been Christenhusz et al., 2011; Rothfels et al., 2012; PPG I, officially documented in “Flora of Taiwan” (DeVol, 2016). Pteridophyte Phylogenetic Group I (PPG I, 2016), 1975, 1979; Huang, 1994, 2003; a total of 597 taxa) and for example, classifies genera and families differently “Manual of Taiwan Vascular Plants” (Kuo, 1997; Yang from the system of Kramer and Green (1990), which had and Liu, 2002; a total of 677 taxa). 824 (infra)species for been widely accepted before the era of molecular Taiwanese pteridophytes are recognized in the updated phylogenetics, and was commonly adopted in many checklist here. However, this figure is very likely an previous floristic works, such as “Manual of Taiwan underestimation, and newly recorded species are Vascular Plants, vol. 1” (Kuo, 1997). For the Taiwanese continuously being reported (e.g., Chang et al., 2019; pteridophyte flora, some systems established earlier have 367 Taiwania Vol. 64, No. 4 Fig. 1. Endemic diversity of Taiwanese pteridophytes (selected representatives). A. Isoëtes taiwanensis DeVol var. taiwanensis. B. Hymenophyllum devolii M.J.Lai. C. Lepisorus monilisorus (Hayata) Tagawa. D. Oreogrammitis taiwanensis (Parris & Ralf Knapp) T.C.Hsu. E. Pyrrosia polydactylos (Hance) Ching. F. Woodsia okamotoi Tagawa. G. Adiantum taiwanianum Tagawa. H. Angiopteris somae (Hayata) Makino & Nemoto. I. Diplazium chioui T.C.Hsu. [Photo credit by Yao-Moan Huang (A), Pi-Fong Lu (B– H), and Tian-Chuan Hsu (I)] 368 Dec 2019 TPG : New Pteridophyte checklist of Taiwan been applied, such as Engler’s system (Diels, 1899/1900) et al., 2018; Wei et al., 2018; also see Schuettpelz et al., in DeVol (1975) and Huang (1994), Copeland’s system 2018). To address such issues, when a generic treatment (Copeland, 1947) in Shieh (1972–1978), the system of different from PPG I was proposed by a TPG member, Tryon and Tryon (1982) in Kuo (1985), and Ching’s all members voted in order to find a majority consensus. system (Ching, 1978a,b; Wu and Ching, 1991) in Lu and All scientific names of ferns and lycophytes that Yang (2005). Although these classifications perform were ever cited in any effective publications as occurring well in characterizing pteridophyte genera and families in Taiwan, either indigenous or naturalized, are dealt morphologically, they fail to represent natural with in this paper. The names were first categorized into relationships informed by modern molecular either accepted or nonaccepted ones. To prepare the phylogenetics (Smith et al., 2006; Liu, 2016; PPG I, accepted name checklist, we reviewed the legitimate 2016). names and selected the best representing one for every To organize Taiwanese pteridophytes in a (infra)species taxon. For each accepted (infra)species phylogenetic context, here we provide a classification taxon/name here, its basionym, type information, scheme that is based on the most updated phylogenetic corresponding names in the four previous works (i.e., evidence, and for all taxon with accepted names here, we Huang, 1994; Yang and Liu, 2002; Wu et al., 2013; provide their best corresponding names in Taiwanese Knapp, 2014), and an appropriate Taiwanese Mandarin Mandarin. Our appendix and online file also supply name are given (the first three of these provided only in other details for the Taiwanese pteridophytes in order to the online file and appendix). The nonaccepted names track their names used in the previous floristic works. are categorized as: (i) homotypic (i.e., nomenclatural) Particularly, the online file provides the synonyms that synonyms of accepted taxa; (ii) heterotypic (i.e., will help researchers worldwide to better recognize the taxonomical) synonyms of accepted taxa; (iii) excluded Taiwanese pteridophytes taxonomically. Finally, a names, those recorded in Taiwan exclusively by discussion group (Google discussion group: traceable misidentifications; (iv) doubtfully recorded https://groups.google.com/forum/#!forum/taiwan- names, those without sufficient data to either affirm or pteridophyte-group) is established online for our reject its occurrence in Taiwan; and (v) undetermined community. This public platform will allow more users names, those taxonomic units that were neither validly to follow our further updates or to provide any comments published nor attributed to valid names. Whenever on this new Taiwan pteridophyte checklist. referable [for (i) and (ii)] or traceable [for (iii) and (v)], the corresponding accepted names for each nonaccepted METHODS name is also given. Extensive field and herbaria surveys are also We established a research community - Taiwan conducted to clarify whether additional taxa occur in Pteridophyte Group (TPG) - to prepare an updated Taiwan. Among the unrecorded taxa, a taxon checklist of Taiwanese pteridophytes. Species lists of presumably not introduced due to human activity would different taxonomic groups were first generated by be recognized as an indigenous taxon and added into the different community members. These species lists were accepted name checklist; otherwise it would be regarded prepared by reviewing the name records in four as an adventive taxon. An adventive taxon would be nd reference works - “Flora of Taiwan, 2 edition, vol. 1” further recognized as a naturalized