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— The fern genus Didymochlaena is characterized by having scaly rhizomes and petioles, tufted and bipinnate leaves, dimidiate pinnules, and fewer than 11 sori per pinnule. For a long time only one species was widely recognized in the genus. Most recently, six and seven species from Madagascar and Asia-Pacific regions, respectively, have been recognized based on morphological and/or molecular evidence. In this monographic study we recognize 22 species worldwide, six of which are described as new: D. alpina, D. amazonica, D. cameroonensis, D. comorensis, D. cubensis, and D. mesoamericana. A key to all species is provided, and detailed descriptions, illustrations, and information on their distribution and habitats are given.

Liang, Yong-Yan, Zhang, Li-Bing (2022): Polystichum neocavernicola (subg. Haplopolystichum; Dryopteridaceae), a new cave fern from Guangxi, China. Phytotaxa 559 (1): 95-98, DOI: 10.11646/phytotaxa.559.1.11, URL: http://dx.doi.org/10.11646/phytotaxa.559.1.11

A new species of Ophioglossum, O. isanense, from Northeast Thailand is described and illustrated. It may be diagnosed from other congeners by a combination of morphological characters including: its smaller size, cylindrical rhizome, stoloniferous roots, brownish green common stalk and trophophylls, the presence of persistent leaf sheath at the top of the rhizome and by the unique structure of spores. Molecular study also supported it as a distinct species. A summary of the ecology and an IUCN conservation status of the new species are provided.

We describe a new species of Cyrtomium, C. calcis, from northern Vietnam and southern China, and report new records of six species in two fern genera, Arachniodes and Polystichum, of Dryopteridaceae, i.e., Arachniodes amabilis (from Lamdong Province), A. amoena (Quangtri Province), A. fengii (Nghean Province), A. globisora (Thanhhoa, Quangtri, and Laocai provinces), and A. nigrossora (Vinhphuc Province), and Polystichum ariticulatipilosum (Hagiang Province). The new species of Cyrtomium most closely resembles C. pachyphyllum, but can be distinguished from the latter in the shape of petiole scales, number of lateral pinna pairs, venation, and lamina shape. Detailed description, images, notes, type information, examined specimens, distribution, and habitat are provided for the new species and new records. The status of the new species is provisionally assessed here as endangered (EN) following the IUCN Categories and Criteria.

Wan, Xia, Zhang, Li-Bing (2022): Three new fern names of hybrid genera and four new combinations in Athyriaceae, Osmundaceae, and Thelypteridaceae. Phytotaxa 575 (1): 104-108, DOI: 10.11646/phytotaxa.575.1.8, URL: http://dx.doi.org/10.1094/PDIS-04-22-0755-PDN

The electrochemical carbon dioxide reduction (ECR) into high-value-added chemicals is a promising approach to alleviate the energy crisis and greenhouse effect. However, the lack of efficient, highly selective, and durable electrocatalysts limits the further application of ECR. Herein, a molecular linking strategy is developed to anchor the monodispersed Bi nanoparticles on a carbon matrix, enabling the durable and efficient CO2 reduction into formate. Systematic characterizations and experimental measurements reveal that tetra-aminophenyl porphyrin (TAPP) can act as an effective molecular linker to secure Bi nanoparticles on porous carbon matrix (Bi NPs/TAPP-PC) via its strong interaction with both the support and nanoparticles, resolving the issues of their peel-off and agglomeration during ECR. Benefiting from the linkage of TAPP molecules, Bi NPs/TAPP-PC exhibits significantly improved ECR performance with a Faradaic efficiency of 92.1% and partial current density of 55.8 mA cm–2 as well as a long-term durability of over 20 h, compared with Bi NPs/PC without TAPP. This strategy using a molecular linker to enhance the activity and durability of the host catalyst provides new insights for developing applicable catalysts for diverse electrocatalytic applications.

Comprising about 82% of the extant fern species diversity, Polypodiales are generally believed to have diversified in the Late Cretaceous. We estimated the divergence times of Polypodiales using both penalized likelihood and Bayesian methods, based on a dataset consisting of 208 plastomes representing all 28 families and 14 fossil constraints reflecting current interpretations of fossil record. Our plastome phylogeny recovered the same six major lineages as a recent nuclear phylogeny, but the position of Dennstaedtiineae was different. The present phylogeny showed high resolution of relationships among the families of Polypodiales, especially among those forming the Aspleniineae. The divergence time estimates supported the most recent common ancestor of Polypodiales and its closest relative dating back to the Triassic, establishment of the major lineages in the Jurassic, and a likely accelerated radiation during the late Jurassic and the Early Cretaceous. The estimated divergence patterns of Polypodiales and angiosperms converge to a scenario in which their main lineages were established simultaneously shortly before the onset of the Cretaceous Terrestrial Revolution, and further suggest a pre-Cretaceous hidden history for both lineages. The pattern of simultaneous diversifications shown here elucidate an important gap in our understanding of the Terrestrial Revolution that shaped today's ecosystems.

Polystichum gonggashanense (Dryopteridaceae: sect. Hypopeltis) is described and illustrated from Mt. Gongga (Minyar Gonkar), Sichuan, China. It can be distinguished from its most similar species, P. sinense, by the blackish brown petiole scales, the oblong-lanceolate lamina, and narrowly lanceolate rachis scales. The new species is found in four populations each with a few individuals and one of the populations has already disappeared. It is classified as CR (Critically Endangered) category based on the IUCN criteria.

The Asplenium wrightii complex is morphologically variable and difficult in species delimitation. Owing to lack of comprehensive sampling in phylogenetic studies, the taxonomy of this complex remains unresolved. Based on extensive field observations, specimen examination and our recent molecular data, the present study aims to clarify the identities of three species of Asplenium in this complex from Asia. Our study revealed that A. alatulum and A. subcrenatum, previously treated as synonyms of A. wrightii, should be reinstated. A taxonomic revision of the three species, including their type information, detailed descriptions, voucher specimens, distribution, ecology, as well as taxonomic notes, is carried out.

A new fern species, Selliguea wusugongii (Polypodiaceae), is described from southeastern Xizang, China. Morphologically, S. wusugongii is distinguished in the genus by having long need-like fronds with width of the lamina only 0.8–1.1 mm, and is the species with the narrowest laminae in selligueoid ferns. The new species is most similar to some Malay selligueoid ferns in morphology, S. bisulcata and S. subsparsa for example, by having simple fronds, narrow laminae and marginal rounded sori, but differs from them in having considerably more scattered scales, frond monomorphic and up to 40 cm long. A phylogenetic analysis based on five plastid markers supported the new species as most closely related to S. rhynchophylla. However, the two species are different from each other in quite a few morphological characteristics, such as the size of fronds and the visibility of venation, and the position of sori.

Two new fern species, Polystichum dongchuanense and P. menglaense (Dryopteridaceae), are described and illustrated from Yunnan, China. Both are members of P. subg. Haplopolystichum sect. Haplopolystichum. Polystichum dongchuanense is most similar to P. acutidens in plant size and pinna size, but the two can be distinguished from each other by pinna serration and soral number on pinnae. Polystichum menglaense is most similar to P. deltodon in plant size, but the two are different in pinna shape and soral distribution. Both new species have extremely narrow distributions and are classified as Critically Endangered (CR) following IUCN Red List Criteria.

A taxonomic revision of Didymochlaena (Didymochlaenaceae) from Asia and the Pacific region is conducted based on morphological and molecular evidence. Seven species are recognized, of which four are described as new and a new status is raised to a species from a variety. These four new species include D. fijiensis from Fiji, D. philippensis from the Philippines, D. punctata from Indonesia, Malaysia, and Thailand, and D. solomonensis from the Solomon Islands. The new status is D. oceanica from Papua New Guinea. Six of the seven species have all been erroneously treated as D. truncatula by earlier pteridologists. A key to the species is provided and descriptions of all species are given.

A new fern species, Leptochilus gracilis, is described and illustrated from southeastern Yunnan, China. Leptochilus gracilis is most similar to L. ellipticus. Compared with L. ellipticus, L. gracilis has a smaller habit with fronds less than 20 cm long, laminae with only one or two pairs of lobes, and midrib of lobes at angles of 45–60 degree with rachis. In contrast, L. ellipticus has a larger habit with fronds more than 30 cm long, laminae with (3–)4–9 pairs of lobes, and midrib of lobes at angles ca. 80–90 degree with rachis. A phylogenetic analysis based on four plastid markers confirmed the recognition of the new species and resulted in an isolated subclade of L. ellipticus clade.

The fern family Didymochlaenaceae contains the genus Didymochlaena only. This genus is generally believed to comprise one species only, while morphological polymorphism in this species has long been observed. Here we conducted a taxonomic revision of Didymochlaena from Madagascar and recognized six species including two new species, three new statuses, and one new combination. A key to the Malagasy species and detailed descriptions of all species recognized are provided.

The biological species concept is not exclusively applicable in many groups of organisms including ferns. Interspecific fern hybrids are not rare: there are 16 intergeneric hybrid genera in ferns confirmed with molecular data. Here we add one more hybrid genus in the tribe Lepisoreae of Polypodiaceae, ×Lepinema, formed via hybridization between parents in two genera: Ellipinema and Lepisorus.

A taxonomic study of Hypodematium (Hypodematiaceae) from Japan is presented. Three species are recognized including H. faurei, H. glanduloso-pilosum, and H. ryukyuense (sp. nov.).

A new species, Selaginella coriaceifolia, is described and illustrated from central Vietnam. The new species can be distinguished from other species in Asia by its habit epilithic, main stem nearly isotomously branched, leaves strongly leathery, ventral leaves imbricate on stem and branch, dorsal leaves with reflexed arista at apex, and sporophylls nearly monomorphic. Molecular and morphological studies of the new species and its allies in S. subg. Heterostachys Baker sect. Heterostachys (Baker) Li Bing Zhang & X.M.Zhou are conducted.

A new fern species, Polystichum neoacutidens (Dryopteridaceae), is described and illustrated from a limestone area in northeastern Thailand. It is distinguished from its closest relative, P. acutidens, by the color of petioles and rachises, density of petiole scales, and position of sori.

A new fern of Polystichum (Dryopteridaceae), P. asia-minoris, is described and illustrated from Horma Canyon in the borders of Küre Mountains National Park in Kastamonu Province located in the north of Turkey. Polystichum asia-minoris is distinguishable from the morphologically similar P. obliquum by having pinnae abaxially densely covered with broad-type microscales. It is not certain to which lineage the new species closely allied. The new species has extremely narrow distribution and is classified as Critically Endangered (CR) following IUCN Red List Criteria.

A new fern species, Athyrium aberrans (Athyriaceae), currently only known from southeastern Xizang, China is described. Morphologically, A. aberrans is superficially similar to A. falcatum in the habit and pinna shape, but the new species can easily be distinguished from the latter by having purplish petioles and rachises, a bulbil on the rachis below the lamina apex, and finely toothed pinna margins. A phylogenetic analysis based on five plastid markers demonstrates that A. aberrans is most closely related to but obviously distinct from A. epirachis.

We tested whether it is beneficial for the accuracy of phylogenetic inference to sample characters that are evolving under different sets of parameters, using both Bayesian MCMC (Markov chain Monte Carlo) and parsimony approaches. We examined differential rates of evolution among characters, differential character-state frequencies and character-state space, and differential relative branch lengths among characters. We also compared the relative performance of parsimony and Bayesian analyses by progressively incorporating more of these heterogeneous parameters and progressively increasing the severity of this heterogeneity. Bayesian analyses performed better than parsimony when heterogeneous simulation parameters were incorporated into the substitution model. However, parsimony outperformed Bayesian MCMC when heterogeneous simulation parameters were not incorporated into the Bayesian substitution model. The higher the rate of evolution simulated, the better parsimony performed relative to Bayesian analyses. Bayesian and parsimony analyses converged in their performance as the number of simulated heterogeneous model parameters increased. Up to a point, rate heterogeneity among sites was generally advantageous for phylogenetic inference using both approaches. In contrast, branch-length heterogeneity was generally disadvantageous for phylogenetic inference using both parsimony and Bayesian approaches. Parsimony was found to be more conservative than Bayesian analyses, in that it resolved fewer incorrect clades. © The Willi Hennig Society 2006.

Contemporary molecular phylogenetic analyses often encompass a broad range of taxonomic diversity while maintaining high levels of sampling within each major taxon. To help maximize phylogenetic signal in such studies, one may analyse multiple levels of characters simultaneously. We test the performance of both the original and the modified versions of non-redundant coding of dependent characters (NRCDC) relative to commonly applied alternative character-sampling strategies using codon-based simulations under a range of conditions. Both original and modified NRCDC generally outperformed other character-sampling strategies that only sampled characters at one level (nucleotides or amino acids) over a broader range of simulation parameters than any of the alternative character-sampling strategies with respect to both overall success of resolution and averaged overall success of resolution in the parsimony-based analyses. Based on theoretical considerations and the results of our simulations, we encourage application and further testing of modified NRCDC in parsimony-based molecular phylogenetic analyses that sample exons of protein-coding genes. We expect that modified NRCDC will generally increase both accuracy and branch-support over commonly applied alternative character-sampling strategies when analysed using the same phylogenetic inference method, particularly in studies that sample both closely and distantly related taxa with clades representing both ancient and recent divergences. (C) The Willi Hennig Society 2010.

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.

A new fern species, Hypodematium eglandulosum, is described and illustrated from southern China and Southeast Asia, and a new combination is made, H. chrysolepis, from Africa. Hypodematium eglandulosum is distinguished from its similar species by plants eglandular, leaves 3-pinnatifid, and stipes upward sparsely covered with acicular hairs or nearly glabrous. The description and photographs of H. eglandulosum are provided. Aspidium chrysolepis is currently treated as a synonym of H. crenatum, but it should be recognized.

Based on morphological and phylogenetic studies, Selaginella qingchengshanensis, a new species in S. sect. Heterostachys from Sichuan, China is described and illustrated. Morphologically, the new species is similar to S. amblyphylla, but has sterile leaves with denticulate to slightly ciliate margins, dorsal leaves with long arista (as long as leaves) perpendicular to stems and branches in living plants, and axillary leaves triangular-ovate or broadly ovate. Molecular analyses based on ITS+5.8S and rbcL data also support it as a distinct species.

As one of the earliest land plant lineages, Selaginella is important for studying land plant evolution. It is the largest genus of lycophytes containing 700-800 species. Some unique characters of Selaginella plastomes have been reported, but based only on 20 species. There have been no plastome phylogenies of Selaginella based on a relatively large sampling, and no efforts have been made to resolve the phylogeny of the enigmatic Sinensis group whose relationships have been unclear based on small datasets. Here we investigated the structures of 59 plastomes representing 51 species covering all six subgenera and 18 sections of Selaginella except two sections and including the intriguing Sinensis group for the first time. Our major results include: (1) the plastome size of Selaginella ranges tremendously from 78,492 bp to 187,632 bp; (2) there are numerous gene losses in Selaginella comparing with other lycophytes, Isoëtaceae and Lycopodiaceae; (3) the gene contents and plastome structures in Selaginella vary lineage-specifically and all infrageneric taxa are well supported in the plastome phylogeny; (4) the ndh gene family tends to lose or pseudogenize in those species with DR structure and without other short or medium repeats; (5) the short and medium repeat regions in SC mediate many conformations causing diverse and complex plastome structures, and six new conformations are discovered; (6) forty-eight species sampled have high GC content (50%) but three species in the Sinensis group have ∼ 30% GC content in plastomes, similar to most vascular plants; (7) the Sinensis group is monophyletic, includes at least two subgroups, and has the smallest plastomes in land plants except some parasitic plants, and their plastomes do not contain any tRNAs; (8) the younger lineages in Selaginella tend to have higher GC content, whereas the older lineages tend to have lower GC content; and (9) because of incomplete genomic data and abnormal structures or some unknown reasons, even the concatenated plastomes could not well resolve the phylogenetic relationships in Selaginella with confidence, highlighting the difficulty in resolving the phylogeny and evolution of this particularly important land plant lineage.

We describe a new species of Asplenium (Aspleniaceae) from Vietnam as A. quangbinhense. Morphologically, it is most similar to A. oldhamii. The new species is closely related to A. pseudopraemorsum, and a morphological comparison is presented between the two species. Three species, A. cyrtosorum, A. maguanense, and A. pseudopraemorsum, are reported as new records for Vietnam based on newly collected specimens from Quang Binh, Ha Giang, and Khanh Hoa provinces, Vietnam, respectively.

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.

Ophioderma redactophylla is described and illustrated as a new species from the Malay Peninsula. It is characterized by vermiform underground parts without tuberous rhizomes, the flat stalks, the linear trophophore, and the sporophore surpassing the trophophore. A taxonomic description and illustrations of the new species are presented. A key to species of Ophioderma is provided.

A taxonomic study of the Hymenasplenium unilaterale subclade (Aspleniaceae) is presented based on morphological and molecular evidence. Twelve species are recognized, nine of which are described as new. The nine new species include H. kinabaluense, H. solomonense, H. madagascariense, H. nigricostatum, H. neocaledonicum, H. oligosorum, H. queenslandicum, H. samoaense, and H. vanuatuense. Of the 12 species recognized, one occurs in Malaysia, East Africa, and Reunion, one in southern Vietnam, and the rest restricted to 1–2 islands of the Indian Ocean or the Pacific Ocean. These new species have been erroneously treated as H. unilaterale by earlier pteridologists. All species were included in a recent phylogenetic analysis and supported as distinct lineages based on molecular data. A key to the species and information on their distributions, habitats, and major distinguishing characters are provided.