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Abstract Parablechnumis the most diverse genus in the fern family Blechnaceae, with about 70 species, mainly from Central and South America, the Austropacific, and a few in Africa. Species delimitation inParablechnumis challenging, and regional studies vary in species recognized. This genus is generally found in humid mid- to high-elevation forests, especially in the Andes. Ecuador is notable for its high species richness, particularly in the poorly explored Cordillera del Cóndor, a sub-Andean range with a distinctive geology contributing to high plant diversity and endemism. Since the early 2000s, botanical expeditions have revealed numerous endemic species, highlighting the region's significance. In 2006, an unusualParablechnumspecies was collected in the Cordillera del Cóndor. Here, we describe it as a new species,Parablechnum shuariorum. It grows on sandstone cliffs along small rivers and can be distinguished by its fertile fronds, which are shorter than its sterile ones, and its densely scaly rachis. This species, endemic to the Cordillera del Cóndor, is found at elevations of 900–1,600 m. It is named after the Shuar people, whose lands include the collection sites. Preliminary conservation assessment suggests thatP. shuariorumis endangered due to a limited area of occupancy and threats from human activities, such as mining. 

Abstract PremiseReticulate evolution, often accompanied by polyploidy, is prevalent in plants, and particularly in the ferns. Resolving the resulting non‐bifurcating histories remains a major challenge for plant phylogenetics. Here, we present a phylogenomic investigation into the complex evolutionary history of the vining ferns,Lygodium(Lygodiaceae, Schizaeales). MethodsUsing a targeted enrichment approach with theGoFlag 408flagellate land plant probe set, we generated large nuclear and plastid sequence datasets for nearly all taxa in the genus and constructed the most comprehensive phylogeny of the family to date using concatenated maximum likelihood and coalescence approaches. We integrated this phylogeny with cytological and spore data to explore karyotype evolution and generate hypotheses about the origins of putative polyploids and hybrids. ResultsOur data and analyses support the origins of several putative allopolyploids (e.g.,L. cubense, L. heterodoxum) and hybrids (e.g.,L.×fayae) and also highlight the potential prevalence of autopolyploidy in this clade (e.g.,L. articulatum, L. flexuosum, andL. longifolium). ConclusionsOur robust phylogenetic framework provides valuable insights into dynamic reticulate evolution in this clade and demonstrates the utility of target‐capture data for resolving these complex relationships. 

The name Parablechnum christii (C. Chr.) Gasper & Salino has been applied to a small species with few pairs of short pinnae that is endemic to Costa Rica and Panama. After reviewing type material of this name, we conclude that it has been misapplied and is, in fact, a synonym of P. falciforme (Liebm.) Gasper & Salino, an older name. Because the specimens previously identified as P. christii lack a name, we propose P. talamancanum S. Molino & R. C. Moran for these plants. The species is endemic to the mountains of Costa Rica and Panama, from 1200 to 3350 m. 

Abstract PremiseThe historical biogeography of ferns is typically expected to be dominated by long‐distance dispersal due to their minuscule spores. However, few studies have inferred the historical biogeography of a large and widely distributed group of ferns to test this hypothesis. Our aims were to determine the extent to which long‐distance dispersal vs. vicariance have shaped the history of the fern family Blechnaceae, to explore ecological correlates of dispersal and diversification, and to determine whether these patterns differ between the northern and southern hemispheres. MethodsWe used sequence data for three chloroplast loci to infer a time‐calibrated phylogeny for 154 of 265 species of Blechnaceae, including representatives of all genera in the family. This tree was used to conduct ancestral range reconstruction and stochastic character mapping, estimate diversification rates, and identify ecological correlates of diversification. ResultsBlechnaceae originated in Eurasia and began diversifying in the late Cretaceous. A lineage comprising most extant diversity diversified principally in the austral Pacific region around the Paleocene–Eocene Thermal Maximum. Land connections that existed near the poles during periods of warm climates likely facilitated migration of several lineages, with subsequent climate‐mediated vicariance shaping current distributions. Long‐distance dispersal is frequent and asymmetrical, with New Zealand/Pacific Islands, Australia, and tropical America being major source areas. ConclusionsAncient vicariance and extensive long‐distance dispersal have shaped the history of Blechnaceae in both the northern and southern hemispheres. The exceptional diversity in austral regions appears to reflect rapid speciation in these areas; mechanisms underlying this evolutionary success remain uncertain. 

Summary Lycopodiaceae are one of three surviving families of lycopsids, a lineage of vascular plants with a fossil history dating to at least the Early Devonian or perhaps the Late Silurian (c. 415 Ma). Many fossils have been linked to crown Lycopodiaceae, but the lack of well‐preserved material has hindered definitive recognition of this group in the paleobotanical record.New, exceptionally well‐preserved permineralized lycopsid fossils from the Early Cretaceous (125.6 ± 1.0 Ma) of Inner Mongolia, China, were examined in detail using acetate peel and micro‐computed tomography techniques. The anatomy of extant Lycopodiaceae was analyzed for comparison using fluorescence microscopy. Phylogenetic relationships of the new fossil to extant Lycopodiaceae were evaluated using parsimony and maximum likelihood analyses.Lycopodicaulis oellgaardiigen. et sp. nov. provides the earliest unequivocal and best‐documented evidence of crown Lycopodiaceae and Lycopodioideae, based on anatomically‐preserved fossil material.Recognition ofLycopodicaulisin Asia during the Early Cretaceous indicates the presence of crown Lycopodiaceae at this time, and striking similarities of stem anatomy with extant species provide a framework for the understanding of the interaction of branching and vascular anatomy in crown‐group lycopsids. 

Summary Sex expression of homosporous ferns is controlled by multiple factors, one being the antheridiogen system. Antheridiogens are pheromones released by sexually mature female fern gametophytes, turning nearby asexual gametophytes precociously male. Nevertheless, not all species respond. It is still unknown how many fern species use antheridiogens, how the antheridiogen system evolved, and whether it is affected by polyploidy and/or apomixis.We tested the response of 68 fern species to antheridiogens in cultivation. These results were combined with a comprehensive review of literature to form the largest dataset of antheridiogen interactions to date. Analyzed species also were coded as apomictic or sexual and diploid or polyploid.Our final dataset contains a total of 498 interactions involving 208 species (c. 2% of all ferns). About 65% of studied species respond to antheridiogen. Multiple antheridiogen types were delimited and their evolution is discussed. Antheridiogen responsiveness was not significantly affected by apomixis or polyploidy.Antheridiogens are widely used by ferns to direct sex expression. The antheridiogen system likely evolved multiple times and provides homosporous ferns with the benefits often associated with heterospory, such as increased rates of outcrossing. Despite expectations, antheridiogens may be beneficial to polyploids and apomicts.