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Graphical abstract Highlights • A large sampling (105 accessions vs. 2–16 accessions in earlier studies) has been achieved. • The species number of the genus is likely to double the most recent estimate following our study. • Leptochilu s is monophyletic and resolved as nested within the microsoroid ferns. • Major evolutionary lineages have been identified. • Leptochilus might have evolved at lower latitudes and progressively dispersed to and colonized higher latitudes. Abstract The newly defined fern genus Leptochilus contains about 50 species occurring in subtropical to tropical Asia and adjacent Pacific islands. The circumscription and phylogeny of the genus have been ambiguous and its species had been included in various genera such as Colysis , Dendroglossa , Kontumia , Microsorum , and Paraleptochilus. Previous molecular studies sampled only 2–4 molecular markers and 2–16 accessions of Leptochilus. In the present study, DNA sequences of six plastid markers of 105 accessions representing ca. 40 species of Leptochilus , including types of Colysis, Kontumia, Leptochilus, and Paraleptochilus , 39 species of six non- Leptochilus genera of Microsoroideae, and one species of Pyrrosia , are used to infer a phylogeny. Our major results include: (1) Leptochilu s is monophyletic and resolved as nested within the microsoroid ferns, but its relationships with other members of Microsoroideae are not well resolved; (2) Six well-supported major clades in Leptochilus are recognized, differing from one another in molecular, morphological, and geographical features; (3) Species related to L. macrophyllus representing earliest split in Leptochilus are identified; (4) The inclusion of Microsorum pteropus in Leptochilus is confirmed, whereas M. insigne is closely related to Leptochilus but not resolved as a member of the genus; (5) The species number of the genus is likely to double the most recent estimate following our study, and quite a few cryptic species should be recognized; and (6) A basal grade formed by three major clades is recovered and they are composed of species almost exclusively distributed at lower latitudes (the Malay Archipelago), whereas the shallow-level clades contain species distributed at mainly higher latitudes, suggesting that Leptochilus might have evolved at lower latitudes and progressively dispersed to and colonized higher latitudes. [ABSTRACT FROM AUTHOR]

The fern genus Hymenasplenium (Aspleniaceae) is one of the two genera in the family. It is generally recognized among modern pteridologists. However, its infrageneric relationships and species diversity have been unclear and controversial. The molecular studies so far have had small taxon and character sampling. In the present study, DNA sequences of six plastid markers of 158 accessions representing ca. 40 out of ca. 50 known species of Hymenasplenium , and 16 species of Asplenium were used to infer a phylogeny with maximum likelihood, Bayesian inference, and maximum parsimony approaches. Our major results include: (1) Hymenasplenium as currently defined is strongly supported as monophyletic; (2) three major clades representing early splits in Hymenasplenium are identified, with the Old World species being strongly supported as monophyletic; it is ambiguous if the New World species are monophyletic; (3) extensive cryptic speciation in the Old World is discovered demonstrating the complexity of evolution of the genus; and (4) six strongly or moderately supported subclades in the Old World clade are revealed, differing from one another in molecular, morphological, and geographical features. [ABSTRACT FROM AUTHOR]

Tectaria (Tectariaceae) is one of the most confusing fern genera in terms of its circumscription and phylogeny. Since its original description, a number of genera had been moved into or related with this genus, while others had been segregated from it. Tectaria is also among the largest fern genera, comprising 150–210 mostly tropical species. Previous molecular studies have been far from comprehensive (sampling no more than 76 accessions from 52 species), limited in geographic scope (mainly restricted to Asia), and based exclusively on plastid markers. In the present study, DNA sequences of eight plastid and one nuclear marker of 360 accessions representing ca. 130 species of Tectaria , ca. 36 species of six non- Tectaria genera in Tectariaceae, 12 species of Davalliaceae, Oleandraceae, and Polypodiaceae, and 13 species of Lomariopsidaceae were used to infer a phylogeny with maximum likelihood, Bayesian inference, and maximum parsimony approaches. Our major results include: (1) the most recently proposed circumscription of Tectaria is strongly supported as monophyletic; (2) the genera Lenda , Microbrochis , Phlebiogonium , and Sagenia , sampled here for the first time, are resolved as part of Tectaria ; (3) four superclades representing early splits in Tectaria are identified, with the Old World species being sister to the New World species; (4) 12 well-supported major clades in Tectaria are revealed, differing from one another in molecular, morphological, and geographical features; (5) evolution of 13 morphological characters is inferred in a phylogenetic context and morphological synapomorphies of various clades are identified; and in particular (6) free venation in Tectaria is inferred to be repeatedly derived from anastomosing venation, an evolutionary phenomenon not documented previously in vascular plants in a phylogenetic context based on both plastid and nuclear evidence. [ABSTRACT FROM AUTHOR]