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Poales are one of the most species-rich, ecologically and economically important orders of plants and often characterise open habitats, enabled by unique suites of traits. We test six hypotheses regarding the evolution and assembly of Poales in open and closed habitats throughout the world, and examine whether diversification patterns demonstrate parallel evolution. We sampled 42% of Poales species and obtained taxonomic and biogeographic data from the World Checklist of Vascular Plants database, which was combined with open/closed habitat data scored by taxonomic experts. A dated supertree of Poales was constructed. We integrated spatial phylogenetics with regionalisation analyses, historical biogeography and ancestral state estimations. Diversification in Poales and assembly of open and closed habitats result from dynamic evolutionary processes that vary across lineages, time and space, most prominently in tropical and southern latitudes. Our results reveal parallel and recurrent patterns of habitat and trait transitions in the species-rich families Poaceae and Cyperaceae. Smaller families display unique and often divergent evolutionary trajectories. The Poales have achieved global dominance via parallel evolution in open habitats, with notable, spatially and phylogenetically restricted divergences into strictly closed habitats. © 2023 The Authors. New Phytologist

Geographic isolation and chromosome evolution are two of the major drivers of diversification in eukaryotes in general, and specifically, in plants. On one hand, range shifts induced by Pleistocene glacial oscillations deeply shaped the evolutionary trajectories of species in the Northern Hemisphere. On the other hand, karyotype variability within species or species complexes may have adaptive potential as different karyotypes may represent different recombination rates and linkage groups that may be associated with locally adapted genes or supergenes. Organisms with holocentric chromosomes are ideal to study the link between local adaptation and chromosome evolution, due to their high cytogenetic variability, especially when it seems to be related to environmental variation. Here, we integrate the study of the phylogeography, chromosomal evolution and ecological requirements of a plant species complex distributed in the Western Euro-Mediterranean region (Carex gr. laevigata, Cyperaceae). We aim to clarify the relative influence of these factors on population differentiation and ultimately on speciation. We obtained a well-resolved RADseq phylogeny that sheds light on the phylogeographic patterns of molecular and chromosome number variation, which are compatible with south-to-north postglacial migration. In addition, landscape genomics analyses identified candidate loci for local adaptation, and also strong significant associations between the karyotype and the environment. We conclude that karyotype distribution in C. gr. laevigata has been constrained by both range shift dynamics and local adaptation. Our study demonstrates that chromosome evolution may be responsible, at least partially, for microevolutionary patterns of population differentiation and adaptation in Carex.

Carex section Schoenoxiphium (Cariceae, Cyperaceae) is endemic to the Afrotropical biogeographic region and is mainly distributed in southern and eastern Africa, with its center of diversity in eastern South Africa. The taxon was formerly recognized as a distinct genus and has a long history of taxonomic controversy. It has also an important morphological and molecular background in particular dealing with the complexity of its inflorescence and the phylogenetic relationships of its species. We here present a fully updated and integrative monograph of Carex section Schoenoxiphium based on morphological, molecular and cytogenetic data. A total of 1,017 herbarium specimens were examined and the majority of the species were studied in the field. Previous molecular phylogenies based on Sanger-sequencing of four nuclear and plastid DNA regions and RAD-seq were expanded. For the first time, chromosome numbers were obtained, with cytogenetic counts on 44 populations from 15 species and one hybrid. Our taxonomic treatment recognizes 21 species, one of them herein newly described (C. gordon-grayae). Our results agree with previous molecular works that have found five main lineages in Schoenoxiphium. We provide detailed morphological descriptions, distribution maps and analytical drawings of all accepted species in section Schoenoxiphium, an identification key, and a thorough nomenclatural survey including 19 new typifications and one nomen novum.

Changes in holocentric chromosome number due to fission and fusion have direct and immediate effects on genome structure and recombination rates. These, in turn, may influence ecology and evolutionary trajectories profoundly. Sedges of the genus Carex (Cyperaceae) comprise ca. 2000 species with holocentric chromosomes. The genus exhibits a phenomenal range in the chromosome number (2n = 10 − 132) with almost not polyploidy. In this study, we integrated the most comprehensive cytogenetic and phylogenetic data for sedges with associated climatic and morphological data to investigate the hypothesis that high recombination rates are selected when evolutionary innovation is required, using chromosome number evolution as a proxy for recombination rate. We evaluated Ornstein–Uhlenbeck models to infer shifts in chromosome number equilibrium and selective regime. We also tested the relationship between chromosome number and diversification rates. Our analyses demonstrate significant correlations between morphology and climatic niche and chromosome number in Carex. Nevertheless, the amount of chromosomal variation that we are able to explain is very small. We recognized a large number of shifts in mean chromosome number, but a significantly lower number in climatic niche and morphology. We also detected a peak in diversification rates near intermediate recombination rates. In combination, these analyses point toward the importance of chromosome evolution to the evolutionary history of Carex. Our work suggests that the effect of chromosome evolution on recombination rates, not just on reproductive isolation, may be central to the evolutionary history of sedges.

Aim: Madagascar is renowned for its unparalleled biodiversity and endemism. With many ecosystems under threat, research is urgently needed on its unique plant diversity. This applies both to Madagascar's forests and treeless vegetation types. Sedges (Cyperaceae) are among the top 10 species-richest angiosperm families in Madagascar (310 native species, 38% endemic), of which two-thirds occur in open habitats. We aimed to infer the evolutionary history of sedges in Madagascar, by estimating the number, age and origins of endemic lineages, and how they diversified on the island. We tested contrasting hypotheses of (a) few colonizations but important in situ radiations against (b) a high number of anagenetic colonizations. Location: Madagascar and the surrounding Indian Ocean islands, integrated within a global dataset. Taxon: Sedge family Cyperaceae. Methods: We estimated time-calibrated molecular phylogenies encompassing a large proportion of Madagascar's known sedge flora (incl. 55% of native species), integrating sequence data for 1,382 accessions representing almost 25% of the c. 5,600 sedge species worldwide, combined with ancestral area reconstruction, diversification analyses and Bayesian stochastic mapping. Results: Cyperaceae lineages arrived in Madagascar from c. 40 Mya with many arriving more recently. About 20 endemic lineages of Cyperaceae occur on the island, of which only six encompass more than five species. All except one of the endemic lineages that diversified in Madagascar use the C3 photosynthetic pathway. The main biogeographical links of Madagascar's sedge flora are to Southern and Tropical Africa. Main conclusions: The biogeographical history of Cyperaceae in Madagascar is a chronicle of relatively recent multiple in and out processes of long-distance dispersal colonizations constrained by distance. Also, the Madagascar region is not only a ‘sink’ for immigrant taxa, in situ diversification and dispersal to other regions also occurred. Some of

Large-scale changes in chromosome number have been associated with diversification rate shifts in many lineages of plants. For instance, several ancient rounds of polyploidization events have been inferred to promote genomic differentiation and/or isolation and, consequently, angiosperm diversification. Dysploidy, although less studied, has been suggested to also play an important role in angiosperm diversification. In this article, we aim to elucidate the role of chromosomal rearrangements on lineage diversification by analyzing a new comprehensive sedge (Cyperaceae) phylogenetic tree. Our null hypothesis is that the mode and tempo of chromosome evolution are to be homogeneous across the complete phylogeny. In order to discern patterns of diversification shifts and chromosome number changes within the family tree, we tested clade-specific chromosome evolution models for several subtrees according to previously reported increments of diversification rates. Results show that a complex, heterogeneous model composed of different clade-specific chromosome evolution transitions are significantly supported against the null hypothesis of a model with no chromosome number model transition events along the phylogeny. This could suggest a link between diversification and changes in chromosome number evolution although other possibilities are not discarded. Our methodological approach may allow identifying different patterns of chromosome evolution, as found for Cyperaceae, for other lineages at different evolutionary levels.

The megadiverse genus Carex (c. 2000 species, Cyperaceae) has a nearly cosmopolitan distribution, displaying an inverted latitudinal richness gradient with higher species diversity in cold-temperate areas of the Northern Hemisphere. Despite great expansion in our knowledge of the phylogenetic history of the genus and many molecular studies focusing on the biogeography of particular groups during the last few decades, a global analysis of Carex biogeography and diversification is still lacking. For this purpose, we built the hitherto most comprehensive Carex-dated phylogeny based on three markers (ETS–ITS–matK), using a previous phylogenomic Hyb-Seq framework, and a sampling of two-thirds of its species and all recognized sections. Ancestral area reconstruction, biogeographic stochastic mapping, and diversification rate analyses were conducted to elucidate macroevolutionary biogeographic and diversification patterns. Our results reveal that Carex originated in the late Eocene in E Asia, where it probably remained until the synchronous diversification of its main subgeneric lineages during the late Oligocene. E Asia is supported as the cradle of Carex diversification, as well as a “museum” of extant species diversity. Subsequent “out-of-Asia” colonization patterns feature multiple asymmetric dispersals clustered toward present times among the Northern Hemisphere regions, with major regions acting both as source and sink (especially Asia and North America), as well as several independent colonization events of the Southern Hemisphere. We detected 13 notable diversification rate shifts during the last 10 My, including remarkable radiations in North America and New Zealand, which occurred concurrently with the late Neogene global cooling, which suggests that diversification involved the colonization of new areas and expansion into novel areas of niche space.

Premise of research. The Schoenoxiphium clade (Carex, Cyperaceae) exhibits a high species diversity in South Africa and a complex taxonomy. Previous phylogenetic studies did not resolve the species relationships within the Schoenoxiphium clade due to the lack of informative characters in DNA markers used. Our aim is to resolve the species relationships within the Schoenoxiphium clade by adding information from more markers and more samples to information from previous studies. Methodology. We sampled 19 out of 20 recognized species in the former genus Schoenoxiphium. Four DNA regions (two nuclear ribosomal: internal transcribed spacer, external transcribed spacer; two plastid: matK and rps16) were sequenced for 134 samples. Phylogenetic reconstruction was performed using Bayesian inference and maximum likelihood analyses. Pivotal results. The monophyly of the Schoenoxiphium clade was confirmed. Five main clades with strong support were retrieved in congruence with a previous phylogeny. Although species relationships within these clades are still partially unresolved, our phylogeny highlights the need for the description of at least two new species in this group. Conclusions. The monophyly of the former genus Schoenoxiphium, taken together with its morphological synapomorphies and the recent phylogenetic studies and subsequent recircumscription of the genus Carex to include all nested genera, advises the consideration of this clade as a section (Carex sect. Schoenoxiphium Baillon). Additional investigations based on genomic sequencing are needed to fully resolve the species relationships within each of the five main clades.

This study present new records of bryophytes based on the collections made along the years 2016 and 2017 in both oro and cryoromediterranean bioclimatic subzones of Gredos mountain range, which were scarcely collected. Among the findings, we highlight Douinia ovata , unknown up to date for the Mediterranean Region of Spain, and Sciuro-hypnum reflexum and Tortula hoppeana , both new to the Central System. Also, we highlight the finding of 4 liverworts and 24 mosses news to the Autonomous Community of Extremadura, some of which also unknown either for Gredos mountain range or Ávila or Salamanca provinces. Finally, records of new populations of very rare bryophytes in Gredos or the Iberian Central System are included., En este artículo se presentan numerosas novedades corológicas de interés, basadas en las colectas llevadas a cabo durante los años 2016 y 2017 en los pisos oro y crioromediteráneo de la sierra de Gredos, zonas que habían sido escasamente colectadas. Entre los resultados destacamos el hallazgo de Douinia ovata, desconocida de la región mediterránea española, y de Sciuro-hypnum reflexum y Tortula hoppeana, nuevos para el Sistema Central en su conjunto. Destacamos también 4 hepáticas y 24 musgos nuevos para la Comunidad Autónoma de Extremadura, así como otras no conocidas para la sierra de Gredos o las provincias de Ávila o Salamanca. Por último, se incluyen citas de nuevas poblaciones de briófitos muy raros en Gredos o el Sistema Central en su conjunto

This study present new records of bryophytes based on the collections made along the years 2016 and 2017 in both oro and cryoromediterranean bioclimatic subzones of Gredos mountain range, which were scarcely collected. Among the findings, we highlight Douinia ovata, unknown up to date for the Mediterranean Region of Spain, and Sciuro-hypnum reflexum and Tortula hoppeana, both new to the Central System. Also, we highlight the finding of 4 liverworts and 24 mosses news to the Autonomous Community of Extremadura, some of which also unknown either for Gredos mountain range or Ávila or Salamanca provinces. Finally, records of new populations of very rare bryophytes in Gredos or the Iberian Central System are included., En este artículo se presentan numerosas novedades corológicas de interés, basadas en las colectas llevadas a cabo durante los años 2016 y 2017 en los pisos oro y crioromediteráneo de la sierra de Gredos, zonas que habían sido escasamente colectadas. Entre los resultados destacamos el hallazgo de Douinia ovata, desconocida de la región mediterránea española, y de Sciurohypnum reflexum y Tortula hoppeana, nuevos para el Sistema Central en su conjunto. Destacamos también 4 hepáticas y 24 musgos nuevos para la Comunidad Autónoma de Extremadura, así como otras no conocidas para la sierra de Gredos o las provincias de Ávila o Salamanca. Por último, se incluyen citas de nuevas poblaciones de briófitos muy raros en Gredos o el Sistema Central en su conjunto

Carex sect. Schoenoxiphium (18 spp.) is a monophyletic group that has its centre of diversity in eastern south Africa. We describe two new species from the Republic of South Africa and Lesotho on the basis of morphological characters. Both new species (C. badilloi and C. parvirufa) are closely related to C. ludwigii, C. kukkoneniana and C. pseudorufa.

Despite the significant increase of bryological studies in Spain during the last decades, some regions remain poorly studied. This is the case of Sierra de Gredos mountain range, in the Iberian Central System, which we visited in several collecting expeditions, with focus in the insufficiently explored high mountain areas. As a result, we highlight 28 taxa either by their importance in bryological conservation or because those populations are the first evidence of the taxa in the Iberian Central System. It is remarkable the presence of Kiaeria falcata, never collected previously in the Iberian Peninsula although reported in error based on K. starkei specimens, and Polytrichastrum sexangulare, known so far in the Iberian Peninsula only from the Pyrenees. Likewise, we highlight the new populations of Andreaea nivalis, Anthoceros caucasicus, Kiaeria blyttii, Meesia triquetra, and Polytrichum longisetum. The first one is reported fertile for the first time in Spain. In addition, we found 13 species listed in different threat categories whose number of populations and/or Area of Occupancy (AOO) is inconsistent with the category to that they have been assigned in Spain. Thus, four endangered species proved to be relatively common in the Central System; consequently, we propose to withdraw these species from the list of threatened bryophytes in Spain. This study highlights the urgent need to deepen into the taxonomic and chorological research of Spanish bryological biodiversity to set a solid basis on which an adequate and efficient conservation management may be performed. Finally, taxonomic and ecological comments are indicated for some species.

Mediterranean‐type ecosystems (MTEs) have long attracted the attention of biologists worldwide. One of the main reasons is the tremendous vascular plant diversity within the five MTEs, including the Mediterranean Basin, southwestern and southern Australia, coastal and southern regions of California, central Chile and the Cape Region in South Africa. Mediterranean‐type ecosystems harbor almost 20%, i.e., about 50,000 species, of the world's known vascular plant species on less than 5% of the Earth's surface (Cowling et al., 1996). A combination of geological stability, climatic oscillations, fire frequency, and summer droughts created unique plant communities and floras with characteristic, unmistakable names, such as matorral, chaparral, maquis, fynbos and kwongan. Such a great interest in MTEs by the international scientific community was given concrete expression in 1971, when the International Society for Mediterranean Ecology (ISOMED) was established to promote research, conservation, and public awareness of the biological diversity of the world's Mediterranean‐type climate regions. Since then, the International Mediterranean Ecosystems Conference (MEDECOS) has periodically been held, rotating among Mediterranean‐type climate countries every 3–4 yr, to bring together scientists and natural resource managers with a strong interest in MTEs.

PREMISE OF THE STUDY: The sedge Carex macloviana d’Urv presents a bipolar distribution. To clarify the origin of its distribution, we consider the four main hypotheses: long-distance dispersal (either by mountain hopping or by direct dispersal), vicariance, parallel evolution, and human introduction. METHODS: Phylogenetic, phylogeographic, and divergence time estimation analyses were carried out based on two nuclear ribosomal (ETS and ITS) regions, one nuclear single copy gene (CATP), and three plastid DNA regions (rps 16 and 5′ trn K introns, and psb A-trn H spacer), using Bayesian inference, maximum likelihood, and statistical parsimony. Bioclimatic data were used to characterize the climatic niche of C. macloviana. KEY RESULTS: C arex macloviana constitutes a paraphyletic species, dating back to the Pleistocene (0.62 Mya, 95% highest posterior density: 0.29–1.00 Mya). This species displays strong genetic structure between hemispheres, wiThtwo different lineages in the Southern Hemisphere and limited genetic differentiation in Northern Hemisphere populations. Also, populations from the Southern Hemisphere show a narrower climatic niche wiThregards to the Northern Hemisphere populations. CONCLUSIONS: C arex macloviana reached its bipolar distribution by long-distance dispersal, although it was not possible to determine whether it was caused by mountain hopping or by direct dispersal. While there is some support that Carex macloviana might have colonized the Northern Hemisphere by south-to-norThtranshemisphere dispersal during the Pleistocene, unlike the southwards dispersal pattern inferred for other bipolar Carex L. species, we cannot entirely rule out north-to-souThdispersion.