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Grammitidoideae are the largest subfamily in Polypodiaceae and contain about 911 species. Progress has been made in understanding the overall phylogeny and generic boundaries in the light of recent molecular works. However, the majority of species, especially Asian species, and some critical type species of genera remain unsampled. In this study, a dataset of six plastid markers of 1003 (112 new) accessions representing ca. 412 species of Grammitidoideae including the type species of Ctenopterella, Grammitis, Moranopteris, Radiogrammitis, and Themelium, was assembled to infer a phylogeny. Our major results include: (1) the type species of Grammitis is successfully sequenced using a next‐generation sequencing technique and is resolved in Grammitis s.str. as expected; (2) Ctenopterella is found to be polyphyletic and a new clade consisting of C. khaoluangensis is resolved as sister to Tomophyllum; (3) the type species of Ctenopterella is resolved in a clade sister to the C. lasiostipes clade; (4) Oreogrammitis is found to be polyphyletic and three clades outside of the core Oreogrammitis are identified containing O. subevenosa and allies, O. orientalis, and O. beddomeana (+ O. cf. beddomeana); (5) Prosaptia is found to be paraphyletic with P. nutans being sister to a clade containing the rest of Prosaptia and Archigrammitis; (6) the intergeneric and major relationships within the Asia‐Pacific clade are well resolved and strongly supported except for a few branches; (7) extensive cryptic speciation is detected in the Asia‐Pacific clade; and (8) based on the polyphyly of Ctenopterella we describe three new genera, Boonkerdia, Oxygrammitis, and Rouhania, for species formerly in Ctenopterella; because the type species of Grammitis belongs to Grammitis s.str., we describe five new genera, Aenigmatogrammitis, Grammitastrum (stat. nov.), Howeogrammitis, Nanogrammitis, and Thalassogrammitis for species formerly in Grammitis s.l. A key to the 35 Old‐World genera is given, a taxonomic treatment is presented, and the morphology of all new genera is shown with either a color plate and/or a line drawing. [ABSTRACT FROM AUTHOR]

Lycopodiaceae are one of the oldest lineages of any living vascular plants and contain about 400 species distributed on all continents except Antarctica, with its highest diversity in tropical regions. Previous studies on the morphology, anatomy, and molecular systematics of Lycopodiaceae have made substantial progress in understanding the diversity and evolution of the family, but major issues remain. In particular, earlier studies had relatively sparse taxon sampling, some critical relationships among the genera have not been well resolved, and the monophyly of some genera (e.g., Huperzia, Lycopodiella, Pseudolycopodiella, Spinulum) has not been robustly tested with large sampling. In this study, we apply maximum likelihood, maximum parsimony, and Bayesian inference to a dataset of 1150 (918 newly generated) DNA sequences of seven plastid markers (atpA, psbA‐trnH, rbcL, rps4, rps4‐trnS, trnL, trnL‐F) of 334 accessions representing ca. 155 (ca. 39% of all) species in the family to infer a global phylogeny. Our major results include: (1) the tree is resolved into three primary clades corresponding to the three subfamilies, Huperzioideae, Lycopodioideae, and Lycopodielloideae; (2) these three primary clades are resolved into 17 major clades, of which 16 represent genera recognized in the PPG I classification, while Lycopodiella serpentina is resolved as sister to Palhinhaea, and thus a new genus, Brownseya, is described, and a key to genera of Lycopodielloideae is given; (3) Phylloglossum is strongly or moderately supported as sister to Phlegmariurus in ML and MP analyses (but not in BI analysis), and thus our evidence supports the recognition of Phlegmariurus in order to maintain a monophyletic Huperzia; (4) Lycopodiella is sister to Pseudolycopodiella and they together are sister to Lateristachys + (Brownseya + Palhinhaea); (5) Huperzia, Lycopodiella, Pseudolycopodiella, and Spinulum are each strongly supported as monophyletic; (6) spore morphology is well consistent with the phylogenetic relationships in the family; and (7) based on these results we recognize 17 genera in three subfamilies in the family. [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]

The taxonomy of the cliff fern family Woodsiaceae has been controversial with 22–59 species in 1–7 genera recognized in various classifications. This is mainly due to limited taxon sampling (up to 33 accessions representing up to 21 species) and poor resolution in molecular studies so far. In the present study, DNA sequences of five plastid markers (atpA, matK, rbcL, rps4 + rps4‐trnS, trnL + trnL‐F) of 152 accessions representing ca. 43 out of ca. 65 species estimated of Woodsiaceae (122 accessions), and 30 non‐Woodsiaceae accessions from the most closely related four families (Athyriaceae, Blechnaceae, Onocleaceae, Thelypteridaceae) were used to infer a phylogeny. Our major results include: (1) Woodsiaceae are strongly supported as monophyletic; (2) Two major clades representing the deepest split in Woodsiaceae are identified, corresponding to the two recently proposed subfamilies, Woodsioideae and Protowoodsioideae; (3) Within Woodsioideae and Protowoodsioideae, two and three well‐supported subclades, respectively, are determined; (4) Cheilanthopsis is resolved as paraphyletic in relation to Hymenocystis (sampled for the first time) and Protowoodsia; (5) Physematium and Woodsiopsis are paraphyletic in relation to a clade containing Cheilanthopsis, Hymenocystis, and Protowoodsia; (6) Evolution of 13 morphological characters is inferred in a phylogenetic context, and morphological synapomorphies of each of the five major subclades are identified; (7) We propose to recognize two genera in Woodsiaceae based on deep divergence (ca. 45 Ma), morphology, chromosome number, and geographic distribution: Physematium (syn.: Cheilanthopsis, Hymenocystis, Protowoodsia, Woodsiopsis) and Woodsia (syn.: Eriosoriopsis), and Physematium is further divided into three subgenera and Woodsia into two subgenera; (8) we describe ×Woodsimatium, a hybrid genus (nothogen. nov.) between the two genera recognized. A taxonomic synopsis of the family is provided, and 15 new combinations are made. [ABSTRACT FROM AUTHOR]

The lycophyte genus Selaginella alone constitutes the family Selaginellaceae, the largest of the lycophyte families. The genus is estimated to contain 700-800 species distributed on all continents except Antarctica, with highest species diversity in tropical and subtropical regions. The monophyly of Selaginella in this broad sense has rarely been doubted, whereas its intrageneric classification has been notoriously contentious. Previous molecular studies were based on very sparse sampling of Selaginella (up to 62 species) and often used DNA sequence data from one genome. In the present study, DNA sequences of one plastid ( rbcL) and one nuclear ( ITS) locus from 394 accessions representing approximately 200 species of Selaginella worldwide were used to infer a phylogeny using maximum likelihood, Bayesian inference and maximum parsimony methods. The study identifies strongly supported major clades and well resolves relationships among them. Major results include: (i) six deep-level clades are discovered representing the deep splits of Selaginella; and (ii) 20 major clades representing 20 major evolutionary lineages are identified, which differ from one another in molecular, macro-morphological, ecological and spore features, and/or geographical distribution. [ABSTRACT FROM AUTHOR]