© 2017 The Linnean Society of London, Botanical Journal of the Linnean Society, 2017, 183, 545–560 545 Botanical Journal of the Linnean Society, 2017, 183, 545–560. With 10 figures. A systematic study of East Asian vittarioid ferns (Pteridaceae: Vittarioideae) CHENG-WEI CHEN 1 , STUART LINDSAY 2 , LI-YAUNG KUO 3 , CHRISTOPHER R. FRASER-JENKINS 4 , ATSUSHI EBIHARA 5 , HONG TRUONG LUU 6 , CHONG WOOK PARK 7 , YI-SHAN CHAO 8 *, YAO-MOAN HUANG 1 * and WEN-LIANG CHIOU 9,10 1 Division of Sylviculture, Taiwan Forestry Research Institute, Taipei 10066, Taiwan 2 Gardens by the Bay, 18 Marina Gardens Drive, Singapore 018953 3 Institute of Ecology and Evolutionary Biology, National Taiwan University, Taiwan 10617 4 Student Guest House, Tridevi Marg, Thamel, P.O. Box no. 5555, Kathmandu, Nepal 5 Department of Botany, The National Science Museum, Tsukuba 305-0005, Japan 6 Southern Institute of Ecology, Vietnam Academy of Science and Technology, HCMC 70000, Vietnam 7 School of Biological Sciences, Seoul National University, Seoul 08826, Republic of Korea 8 Department of Biomedical Science and Environmental Biology, Kaohsiung Medical University, Kaohsiung 80708, Taiwan 9 Division of Botanical Garden, Taiwan Forestry Research Institute, Taipei 10066, Taiwan 10 Dr. Cecilia Koo Botanic Conservation and Environmental Protection Foundation/Conservation Center, Pingtung 90646, Taiwan Received 26 May 2016; revised 11 November 2016; accepted for publication 6 January 2017 A systematic study of the vittarioid ferns of East Asia including China, Japan, Korea and Taiwan is presented based on an integrated analysis of morphology and molecular phylogeny. Several new taxonomic insights are derived from well-resolved phylogenetic trees and detailed morphological comparison. The morphological varia- tion and molecular phylogenetic relationships among the taxa of the Haplopteris taeniophylla complex are pre- sented and discussed. Molecular phylogenetic evidence support the lumping of several morphological forms (each previously recognized as a species) under Haplopteris flexuosa. In addition, two historically misapplied names (Haplopteris amboinensis and Vaginularia paradoxa) and the species delimitation of three morphologically similar species pairs (Antrophyum formosanum vs. A. henryi, A. annamense vs. A. callifolium and Haplopteris elongata vs. H. ensiformis) are clarified. ADDITIONAL KEYWORDS: Antrophyum – Haplopteris – morphology – phylogeny – taxonomy – Vaginularia. INTRODUCTION The vittarioid ferns were previously classified at the family level as Vittariaceae (Kramer, 1990), but are currently resolved as a clade of Pteridaceae sister to Adiantum L. ( Schuettpelz et al. , 2007; Rothfels & Schuettpelz, 2014) and currently treated as part of Pteridaceae subfamily Vittarioideae ( Smith et al ., 2006; Christenhusz, Zhang & Schneider, 2011; Christenhusz & Chase, 2014). A recent study of subfamily Vittarioideae ( Schuettpelz et al. , 2016) revealed 11 morphologically distinguishable sub- clades, each of which may be treated as a genus. Only three of these genera, Antrophyum Kaulf., Haplopteris C.Presl and Vaginularia Fée, are found in East Asia (defined here as China, Japan, Korea and Taiwan). The taxonomic history of East Asian vittarioid ferns dates back to 1867, when Vittaria japonica Miq., a spe- cies now usually treated as a synonym of Haplopteris flexuosa (Fée) E.H.Crane, was described from Japan (Miquel, 1867). In the early 1900s, an additional 17 species were described from China, Japan and Taiwan *Corresponding author. E-mail: pteridaceae@gmail.com; huangym@tfri.gov.tw Downloaded from https://academic.oup.com/botlinnean/article/183/4/545/3739730 by guest on 13 January 2022