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Leucostegia has been long recognized as a small fern genus with only two species, L. immersa and L. pallida. Here we elevate a variety of L. immersa to species level and make the new combination Leucostegia amplissima based on morphological and molecular phylogenetic evidence. Morphologically, Leucostegia amplissima differs from L. immersa by having larger evergreen fronds, smaller indusia, and glandular hairs on the basal stipes. The study of Taiwanese populations further suggested an ecological divergence between L. immersa and L. amplissima. [ABSTRACT FROM AUTHOR]

As an ancient lineage of ferns, Ophioglossaceae are evolutionarily among the most fascinating because they have the highest chromosome count of any known organism as well as the presence of sporophores, subterranean gametophytes, eusporangiate sporangia without annuli, and endophytic fungi. Previous studies have produced conflicting results, identifyingsome lineages with unresolved relationships, and have paid much attention to the subfamily Botrychioideae. But the other species‐rich subfamily, Ophioglossoideae, has remained largely understudied and only up to 12 accessions of Ophioglossoideae have been sampled. In this study, DNA sequences of seven plastid markers of 149 accessions (75 in Ophioglossoideae) representing approximately 82 species (approximately 74% of estimated species diversity sensu J. Syst. Evol., 2016, 54, 563) in the family, and two Marattiaceae and two Psilotaceae, are used to infer a phylogeny. Our major results include: (1) Ophioglossaceae are resolved as monophyletic with strong support, and so are all four subfamilies and genera sensu PPG I except Botrypus and Ophioglossum; (2) a new genus Sahashia is segregated from Botrypus so that the monophyly of Botrypus can be retained; (3) the monophyly of Ophioglossum in its current circumscription is uncertain in spite of our large character sampling; (4) there is substantial cryptic speciation in Ophioderma detected by our molecular and morphological study; (5) the recognition of Holubiella is advocated based on its morphology and its sister relationship with Sceptridium; and (6) a novel sister relationship between Botrychium and the JHS clade (Japanobotrychium + (Holubiella + Sceptridium)) is discovered. [ABSTRACT FROM AUTHOR]

The infrageneric relationships and taxonomy of the largest fern genus, Asplenium (Aspleniaceae), have remained poorly understood. Previous studies have focused mainly on specific species complexes involving a few or dozens of species only, or have achieved a large taxon sampling but only one plastid marker was used. In the present study, DNA sequences from six plastid markers (atpB, rbcL, rps4, rps4‐trnS, trnL and trnL‐F) of 1030 accessions (616 of them newly sequenced here) representing c. 420 species of Asplenium (60% of estimated species diversity), 16 species of Hymenasplenium, three Diplaziopsidaceae, and four Rhachidosoraceae were used to produce the largest genus‐level phylogeny yet for ferns. Our major results include: (i) Asplenium as broadly circumscribed is monophyletic based on our inclusion of representatives of 32 of 38 named segregate genera; (ii) 11 major clades in Asplenium are identified, and their relationships are mostly well‐resolved and strongly supported; (iii) numerous species, unsampled in previous studies, suggest new relationships and numerous cryptic species and species complexes in Asplenium; and (iv) the accrued molecular evidence provides an essential foundation for further investigations of complex patterns of geographical diversification, speciation and reticulate evolution in this family. [ABSTRACT FROM AUTHOR]

[Display omitted] • 169 accessions representing ca. 68 (85% of total) species of Bolbitis are sampled. • Species of Bolbitis are resolved into four major clades. • Six well-supported subclades are identified in the most speciose Asian clade. • Evolution of six characters is analyzed and free venation evolved from anastomosing venation in Bolbitis. • Bolbitis originated from Africa and a dispersal from Asia resulted in continental disjunction between Africa and America. Bolbitis is a pantropical fern genus of Dryopteridaceae with ca. 80 species mainly in tropical Asia. Earlier studies confirmed the monophyly of Bolbitis when Mickelia is excluded and identified three major clades in Bolbitis. However, earlier studies are based on relatively small sampling and the majority of Asian species are not sampled. In this study, DNA sequences of three plastid markers of 169 accessions representing ca. 68 (85 % of total) species of Bolbitis in nine out of the 10 series recognized by Hennipman (1977), and 54 accessions representing the five remaining bolbitidoid genera are used to infer a global phylogeny with a focus on Asian species. The major results include: (1) Bolbitis is strongly supported as monophyletic; (2) species of Bolbitis are resolved into four major clades and their relationships are: the Malagasy/Mascarene clade is sister to the rest, followed by the African clade which is sister to the American clade + the Asian clade; (3) six well-supported subclades are identified in the most speciose Asian clade; (4) the free-veined Egenolfia is embedded in Bolbitis and is paraphyletic in relation to species with anastomosing venation; (5) three series sensu Hennipman (1977), B. ser. Alienae , B. ser. Egenolfianae , and B. ser. Heteroclitae , are paraphyletic or polyphyletic; (6) evolution of six morphological characters is analyzed and free venation is found to have evolved from anastomosing venation and reversed to free venation in Bolbitis ; and (7) biogeographical implications are drawn and it is shown that a single recent dispersal from Asia resulted in continental disjunction of closely related ferns of Bolbitis between Africa and America. [ABSTRACT FROM AUTHOR]

[Display omitted] • Hypodematiaceae are found to be sister to the remaining eupolypods I. • Hypodematium is resolved into seven clades. • A latest Jurassic-earliest Cretaceous origin of the family and an Upper Cretaceous origin of two genera are inferred. • Hypodematium appears to have originated from East Asia and dispersed to Africa and Southeast Asia. • Leucostegia appears to have originated from Southeast Asia and/or East Asia. The Old World fern genera Hypodematium and Leucostegia had long been placed in the families Dryopteridaceae and Davalliaceae, respectively, before the advent of molecular phylogenetics. Recent molecular studies confirmed the recognition of the family Hypodematiaceae composed of these two genera, but the relationships within each of these two genera have been unclear. In the present study we performed phylogenetic analyses (MP, ML, BI) based on DNA data from six plastid markers (atpB , atpB-rbcL , matK , rbcL , rps4 & rps4-trnS , and trnL & trnL-F) of 165 accessions representing 31 species in two genera of Hypodematiaceae as the ingroup and 26 accessions representing Cystopteridaceae, Didymochlaenaceae, Dryopteridaceae, Davalliaceae, Oleandraceae, and Woodsiaceae as the outgroups. Our analyses supported the monophyly of the currently defined Hypodematiaceae only including Hypodematium and Leucostegia and found that the family to be sister to the remaining eupolypods I. Our data resolved three taxa of Leucostegia into two clades. In Hypodematium , 28 taxa are resolved into seven strongly supported clades or single-accession clades. The evolution of important morphological characters are inferred in the phylogenetic context. Our dated phylogeny suggested a latest Jurassic-earliest Cretaceous origin of the family and Upper Cretaceous origin of two genera, with Hypodematiaceae originated from East Asia; extant lineages of Hypodematium originated from East Asia and subsequently into Africa, the Indian region, the Madagascar region, and Southeast Asia; and Leucostegia originated from East Asia and/or Southeast Asia. [ABSTRACT FROM AUTHOR]

• Complete or nearly complete sampling of non- Lepisorus genera is achieved. • All seven genera except Lepisorus in Lepisoreae are confirmed to be monophyletic. • Ellipinema is described as new to maintain the monophyly of Lepisorus. • Relationships of major clades are well resolved and strongly supported. • We propose an eight-genus classification based on the phylogeny, morphology, distribution. Lepisoroid ferns (tribe Lepisoreae, Polypodiaceae) are arguably one of the most confusing fern groups in Polypodiaceae in terms of delimitation of genera largely because of their simple morphology. Previous molecular studies either had very small taxon sampling of the non- Lepisorus genera and did not well resolve the relationships among these genera, or had a relatively large sampling at species level but the critical species were missing or their relationships were not well resolved. A recent study resolved the newly sampled Lepisorus jakonensis as sister to the remaining genera in Lepisoreae excluding Paragramma , and the authors lumped all the six well recognized genera into Lepisorus. In the present study, to infer a phylogeny we used DNA sequences of five plastid markers (matK, rbcL, rbcL-atpB , rps4 & rps4-trnS, trnL & trnL-F) of 172 accessions representing ca. 44 species of non- Lepisorus genera and 54 accessions representing ca. 50 species of Lepisorus as ingroup, and 10 non-Lepisoreae accessions from the most closely related four genera (Leptochilus , Microsorum , Phymatosorus , and Goniophlebium) in Microsoroideae and one genus (Pyrrosia) in Platycerioideae. Our major results include: (1) All seven currently defined genera except Lepisorus in Lepisoreae are confirmed to be monophyletic; (2) The Lepisorus jakonensis clade is confirmed to be the second earliest diverged lineage in Lepisoreae; (3) Neolepisorus is resolved as sister to the rest in a clade containing all non- Lepisorus genera except Paragramma ; (4) Lemmaphyllum is sister to a clade containing Lepidomicrosorium , Neocheiropteris , and Tricholepidium ; and (5) Ellipinema gen. nov. is segregated from Lepisorus based on the phylogeny and morphology in order to stabilize the current usage of the existing six non- Lepisorus genera and species names in these genera. A key to all eight genera of Lepisoreae is provided. [ABSTRACT FROM AUTHOR]