A systematic study of East Asian vittarioid ferns (Pteridaceae: Vittarioideae)

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 variation and molecular phylogenetic relationships among the taxa of the Haplopteris taeniophylla complex are presented 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.