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Papers by Santi Martin

Research paper thumbnail of Chorological news for Carex (Cyperaceae) in the Iberian Peninsula

Anales de biología, Jun 29, 2023

Se presentan diversas notas corológicas del género Carex para la península ibérica, que incluyen ... more Se presentan diversas notas corológicas del género Carex para la península ibérica, que incluyen novedades provinciales para cuatro especies (C. elata subsp. elata, C. demissa subsp. demissa, C. oedipostyla, C. sylvatica subsp. sylvatica) así como la confirmación provincial (no indicada en Flora iberica) de la presencia de tres taxónes. Proporcionamos asimismo la segunda cita nacional para Portugal de C. reuteriana subsp. mauritanica. Otras tres citas poseen interés corológico al constituir novedades comarcales y/o de sector biogeográfico, o bien segunda cita provincial. Cinco de las novedades revisten interés conservacionista por tratarse de especies o poblaciones amenazadas, incluidas en Listas Rojas y/o protegidas a nivel legal. Por último, hacemos referencia a la posible naturalización de C. pendula.

Research paper thumbnail of Revised lectotypification of Reseda glauca L. (Resedaceae )

Taxon, Oct 1, 2011

The currently accepted lectotype (Herb. Linn. No. 629.4, LINN) of Reseda glauca L. is identifiabl... more The currently accepted lectotype (Herb. Linn. No. 629.4, LINN) of Reseda glauca L. is identifiable as the related species, R. virgata Boiss. & Reuter. The specimen, collected by Löfling in central Spain, was not explicitly cited in Linnaeus's protologue, in contrast to a specimen (at UPS) collected by Burser in the Pyrenees and identifiable as R. glauca of usage. In accordance with Art. 9.10 of the ICBN, we reject the choice of 629.4 (LINN) as lectotype and we designate Burser's specimen as the lectotype of R. glauca L. in its place. This type choice maintains the traditional and current usage of this well-known and widely used Linnaean name.

Research paper thumbnail of <I>Carex modesti</I> (<I>Cyperaceae</I>), a new species from southern Tanzania

Research paper thumbnail of <i>Carex cespitosa</i>: reappraisal of its distribution in Europe

Willdenowia, Dec 5, 2014

BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access t... more BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access titles in the biological, ecological, and environmental sciences published by nonprofit societies, associations, museums, institutions, and presses.

Research paper thumbnail of Biogeography of Flowering Plants: A Case Study in Mignonettes (Resedaceae) and Sedges (Carex, Cyperaceae)

InTech eBooks, Mar 30, 2012

Research paper thumbnail of New Insights into the Systematics of the Schoenoxiphium Clade (<i>Carex</i>, Cyperaceae)

International Journal of Plant Sciences, May 1, 2017

Premise of research. The Schoenoxiphium clade (Carex, Cyperaceae) exhibits a high species diversi... more 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.

Research paper thumbnail of Two independent dispersals to the Southern Hemisphere to become the most widespread bipolar Carex species: biogeography of C. canescens (Cyperaceae)

Botanical Journal of the Linnean Society, Mar 1, 2017

About 30 plant species occur at high latitudes in both hemispheres, thus achieving a so-called bi... more About 30 plant species occur at high latitudes in both hemispheres, thus achieving a so-called bipolar distribution. Six of these species belong to Carex, of which just one, Carex canescens, occurs on two different landmasses in the Southern Hemisphere (South America and Oceania). The goals of this study are (1) to test the various hypotheses accounting for the bipolar disjunction of C. canescens and (2) to elucidate if C. canescens migrated twice from the Northern Hemisphere to the Southern Hemisphere or if it dispersed from South America to Oceania (or vice versa). We obtained and analysed DNA sequences from the nuclear internal and external transcribed spacers (ITS and ETS) and from the plastid 5′ trnK and rps16 introns from 57 populations of C. canescens spanning its bipolar range. We characterized the species distribution climatically by adding 1995 presence data points from the Global Biodiversity Information Facility. Our results suggest a Northern Hemisphere origin of C. canescens during the Pleistocene and two independent long distance-dispersal events to South America and Australia, by either direct dispersal or mountain-hopping. Long-distance dispersal appears to be the most widespread process resulting in the bipolar distribution of Carex spp.

Research paper thumbnail of Reconciling morphology and phylogeny allows an integrative taxonomic revision of the giant sedges of Carex section Rhynchocystis (Cyperaceae)

Botanical Journal of the Linnean Society, Jul 17, 2018

Research paper thumbnail of Is the diversification of Mediterranean Basin plant lineages coupled to karyotypic changes?

Plant Biology, Apr 3, 2017

The Mediterranean Basin region, home to 25,000 species of plants, is included in the worldwide li... more The Mediterranean Basin region, home to 25,000 species of plants, is included in the worldwide list of hotspots of biodiversity. Despite the indisputably important role of chromosome transitions in plant evolution and diversification, no reference study to date has dealt with the possible relationship between chromosome evolution and lineage diversification in the Mediterranean Basin.  Here we study patterns of diversification, patterns of chromosome number transition (either polyploidy or dysploidy), and the relationship between both for 14 Mediterranean Basin angiosperm lineages using previously published phylogenies.  We found a mixed pattern, with half of the lineages displaying a change in chromosome transition rates after the onset of the Mediterranean climate (six increase, one decrease) and the other half (six) experiencing constant rates of chromosome transitions through time. We have also found a heterogenous pattern regarding diversification rates, with lineages exhibiting moderate (five phylogenies) or low (six) initial diversification rates that either increased (six) or declined (five) through time. Our results reveal no clear link between diversification rates and chromosome number transition rates.  By promoting the formation of new habitats and driving the extinction of many species, the Mediterranean onset and the posterior Quaternary climatic oscillations could have been key for the establishment of new chromosomal variants in some plant phylogenies but not in others. While the biodiversity of the Mediterranean Basin may be partly influenced by the chromosomal diversity of its lineages, this study concludes that lineage diversification in the region is largely decoupled from karyotypic evolution.

Research paper thumbnail of Direct long-distance dispersal best explains the bipolar distribution of Carex arctogena (Carex sect. Capituligerae , Cyperaceae)

Journal of Biogeography, Apr 22, 2015

Aim The bipolar disjunction, a biogeographical pattern defined by taxa with a distribution at ver... more Aim The bipolar disjunction, a biogeographical pattern defined by taxa with a distribution at very high latitudes in both hemispheres (> 61° N; > 54° S), is only known to occur in about 30 vascular plant species. Our aim was to use the bipolar species Carex arctogena to test the four classic hypotheses proposed to explain this exceptional disjunction: convergent evolution, vicariance, mountain-hopping and direct long-distance dispersal. Location Arctic/boreal and temperate latitudes of both hemispheres. Methods A combination of molecular and bioclimatic data was used to test phylogeographical hypotheses in C. arctogena. Three chloroplast markers (atpF-atpH, matK and rps16) and the nuclear ITS region were sequenced for all species in Carex sections Capituligerae and Longespicatae; Carex rupestris, C. obtusata and Uncinia triquetra were used as outrgroups. Phylogenetic relationships, divergence-time estimates and biogeographical patterns were inferred using maximum likelihood, statistical parsimony and Bayesian inference. Results Carex sections Capituligerae and Longespicatae formed a monophyletic group that diverged during the late Miocene. Two main lineages of C. arctogena were inferred. Southern Hemisphere populations of C. arctogena shared the same haplotype as a widespread circumboreal lineage. Bioclimatic data shows that Southern and Northern Hemisphere populations currently differ in their ecological regimes. Main conclusions Two of the four hypotheses accounting for bipolar disjunctions may be rejected. Our results suggest that direct long-distance dispersal, probably southwards and mediated by birds, best explains the bipolar distribution of C. arctogena.

Research paper thumbnail of Geographical speciation related to Pleistocene range shifts in the western Mediterranean mountains (<i>Reseda</i> sect. <i>Glaucoreseda</i> , Resedaceae)

Taxon, Apr 1, 2010

Reseda sect. Glaucoreseda is a monophyletic group composed of five endemic tetraploid species wit... more Reseda sect. Glaucoreseda is a monophyletic group composed of five endemic tetraploid species with a disjunct distribution in the high mountains and plateaus of the Iberian Peninsula and Morocco. It was previously suggested that range shifts induced by Quaternary glaciations played an important role in the speciation of the group. We studied the evolution of R. sect. Glaucoreseda in order to infer historical range dynamics and speciation processes, and to understand current distributional patterns. Phylogeographic analyses were performed using nuclear ribosomal ITS and plastid trnL-F and rps16 sequences. Cloning of additive ITS sequences was carried out to elucidate the origin of intra-individual polymorphisms. A dated phylogeny based on ITS and cpDNA (rbcL, matK, trnL-F) sequences was used to estimate divergence times of R. sect. Glaucoreseda. Time estimates using Penalized Likelihood analyses indicate a late Pleistocene diversification of R. sect. Glaucoreseda. Incomplete lineage sorting of ancestral polymorphisms due to recent divergence, rather than rampant hybridisation, is suggested as the main cause of the phylogenetic incongruence detected between nuclear and plastid datasets. Our results support the vicariance hypothesis for population disjunctions in the Iberian Peninsula, in which an ancestral, widespread species could have undergone differentiation by Quaternary interglacial fragmentation. In contrast, long-distance dispersal across the Strait of Gibraltar may have been involved in the colonisation of North African plateaus by R. battandieri.

Research paper thumbnail of A synopsis of the androgynous species of <i>Carex</i> subgenus <i>Vignea</i> (Cyperaceae) in South America

Botanical Journal of the Linnean Society, Mar 26, 2021

This is the first work of a series of thorough studies into the taxonomy and systematics of Carex... more This is the first work of a series of thorough studies into the taxonomy and systematics of Carex in South America. Here, we present the systematic placement, biogeographic insights, taxonomic accounts, formal typifications and summarized distributions for the 24 species of Carex subgenus Vignea with androgynous spikes in the continent. We performed a phylogenetic study using the barcode markers ETS, ITS and matK to check the placement of 22 of these species on a previous tree with > 1000 Carex spp. We examined > 600 specimens from 38 herbaria and conducted an exhaustive nomenclatural survey consulting all pertinent literature. South American androgynous species of subgenus Vignea are grouped in seven distinct lineages, corresponding with the same number of inferred colonizations. Most groups seem to have colonized South America during the Plio-Pleistocene, except for species of section Bracteosae, a local radiation that dates back to the Late Miocene. All colonizations by native species seem to have originated from North America. The two putatively introduced taxa are western Palaearctic species. An identification key is provided for the studied species. We make 19 new typifications and a new species (Carex pedicularis) is described.

Research paper thumbnail of Cladogenesis

Research paper thumbnail of Tracking gypsophily across the phylogeny: 3 study cases

To gain an evolutionary understanding of plant gypsophily, is essential to incorporate phylogeny ... more To gain an evolutionary understanding of plant gypsophily, is essential to incorporate phylogeny in the analyses. Here we present an overview of three different approaches that we are currently undertaking to tackle this issue. (I) we have selected 5 Iberian genera with gysophite or gypsovag species in which a fairly complete and reliable phylogeny is published (Ononis, Helianthemum, Chaenorrhinum, Reseda and Teucrium). In each of these 5 lineages we plan to explore the events of gypsophily and to evaluate the existence of preadaptations along the clades in terms of ionome. (II) Within the Ononis tridentata-fruticosa-rotundifolia clade, we intend to carry out Hyb-Seq taking the leaf and soil chemical composition into account. Among other biogegraphic and phylogenetic inferences, we are particularly interested on the comparison of the ionome of O. fruticosa populations growing in and out gypsum. (III)We plan to reconstruct the phylogeny of the genus Frankenia based on HybSeq, which comprises a relevant amount of halophyte, gypso-halophyte and gypsum species, particularly in Australia. This worldwide distributed genus is crucial for the understanding of chemical adaptations of gypso-halophytes, a poorly described functional group, but requires a taxonomic and phylogenetic clarification before further analysis. Approaches II and III will use the Angiosperms-353 kit (myBaits), which will allow integrating the results in further studies beyond our current particular purposes

Research paper thumbnail of plb12458-sup-0001-Supinfo

Research paper thumbnail of Dramatic impact of future climate change on the genetic diversity and distribution of ecologically relevant Western Mediterranean <i>Carex</i> (Cyperaceae)

PeerJ, May 31, 2022

Anticipating the evolutionary responses of species to ongoing climate change is essential to prop... more Anticipating the evolutionary responses of species to ongoing climate change is essential to propose effective management and conservation measures. The Western Mediterranean Basin constitutes one of the hotspots of biodiversity where the effects of climate change are expected to be more dramatic. Plant species with ecological relevance constitute ideal models to evaluate and predict the impact of climate change on ecosystems. Here we investigate these impacts through the spatio-temporal comparison of genetic diversity/structure (AFLPs), potential distribution under different future scenarios of climate change, and ecological space in two Western Mediterranean sister species of genus Carex. Both species are ecologically key in their riparian habitats, but display contrasting distribution patterns, with one widespread in the Iberian Peninsula and North Africa (C. reuteriana), while the other (C. panormitana) is a restricted, probably endangered, Central Mediterranean endemic. At present, we found a strong genetic structure driven by geography in both species, and lower values of genetic diversity and a narrower ecological space in C. panormitana than in C. reuteriana, while the allelic rarity was higher in the former than in C. reuteriana subspecies. Future projections predict an overall dramatic reduction of suitable areas for both species under all climate change scenarios, which could be almost total for C. panormitana. In addition, gene diversity was inferred to decrease in all taxa, with genetic structure reinforcing in C. reuteriana by the loss of admixture among populations. Our findings stress the need for a reassessment of C. panormitana conservation status under IUCN Red List criteria and the implementation of conservation measures.

Research paper thumbnail of Systematics of the Giant Sedges of Carex Sect. Rhynchocystis (Cyperaceae) in Macaronesia with Description of Two New Species

Systematic Botany, Aug 11, 2021

— Populations of Carex sect. Rhynchocystis (Cyperaceae) from the Macaronesian archipelagos (Azore... more — Populations of Carex sect. Rhynchocystis (Cyperaceae) from the Macaronesian archipelagos (Azores and Madeira) have traditionally been treated either as a variety of the widely distributed Western Palearctic C. pendula, or directly synonymized under it. However, recent phylogenetic studies have shown that Azorean populations of C. pendula display a certain degree of differentiation from mainland plants, while the phylogenetic relationships of Madeiran populations remain unclear. Here we perform an integrated systematic study focused on the Macaronesian populations of Carex sect. Rhynchocystis to elucidate their phylogenetic relationships and taxonomic status. We reconstructed a molecular phylogeny based on five DNA regions and conducted a multivariate morphological analysis. Divergence time estimates show that the Macaronesian populations can be traced back to a Plio-Pleistocene origin. Our results suggest that these island populations of C. pendula are better treated as two distinct species within Carex sect. Rhynchocystis (i.e. C. leviosa from the Azores and C. sequeirae from Madeira). We provide morphological characters to differentiate the new species from C. pendula s. s., detailed descriptions of the three taxa, a revised key for the entire section, as well as detailed analytical drawings of the two newly described species. We also perform a critical evaluation of the taxonomic diversity of Carex in the Azores and Madeira. Finally, we informally assessed the conservation status of the new species at a global scale under IUCN categories and criteria, resulting in the proposal of the categories Least Concern for C. leviosa and Critically Endangered for C. sequeirae.

Research paper thumbnail of Biogeography and systematics of <i>Carex</i> subgenus <i>Uncinia</i> (Cyperaceae): A unique radiation for the genus <i>Carex</i> in the Southern Hemisphere

Taxon, Feb 23, 2022

Carex subg. Uncinia (Cyperaceae) constitutes one of six currently recognized Carex subgenera. Thi... more Carex subg. Uncinia (Cyperaceae) constitutes one of six currently recognized Carex subgenera. This subgenus is mainly distributed on the American continent and in the Pacific region, and it is the only subgenus almost entirely absent from the Old World and primarily diversified in the Southern Hemisphere. It includes some of the few Carex species with clear epizoochoric traits: the representatives of C. sect. Uncinia possess utricles with an exserted and hooked rachilla that allows the diaspores to attach to feather or hair. We performed phylogenetic (ITS, ETS-1f, matK), biogeographic, and ancestral state reconstruction analyses to elucidate the systematic structure, origin and dispersal routes, and major morphological evolutionary patterns of the different lineages within the subgenus. Our phylogenetic reconstructions revealed that the subgenus comprises seven different clades that mostly match previously recognized sections. One of the clades, however, represents a new section described herein as C. sect. Wheelerianae. Unispicate lineages evolved repeatedly from ancestors bearing multispicate inflorescences, while the presence of a rachilla, often pictured as a plesiomorphy in Carex, seems to have developed four independent times in the evolution of C. subg. Uncinia. The origin of the subgenus This is the author manuscript accepted for publication and has undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record. Please cite this article as

Research paper thumbnail of An Evolutionary Study of Carex Subg. Psyllophorae (Cyperaceae) Sheds Light on a Strikingly Disjunct Distribution in the Southern Hemisphere, With Emphasis on Its Patagonian Diversification

Frontiers in Plant Science, Nov 8, 2021

Carex subgenus Psyllophorae is an engaging study group due to its early diversification compared ... more Carex subgenus Psyllophorae is an engaging study group due to its early diversification compared to most Carex lineages, and its remarkable disjunct distribution in four continents corresponding to three independent sections: sect. Psyllophorae in Western Palearctic, sect. Schoenoxiphium in Afrotropical region, and sect. Junciformes in South America (SA) and SW Pacific. The latter section is mainly distributed in Patagonia and the Andes, where it is one of the few Carex groups with a significant in situ diversification. We assess the role of historical geo-climatic events in the evolutionary history of the group, particularly intercontinental colonization events and diversification processes, with an emphasis on SA. We performed an integrative study using phylogenetic (four DNA regions), divergence times, diversification rates, biogeographic reconstruction, and bioclimatic niche evolution analyses. The crown age of subg. Psyllophorae (early Miocene) supports this lineage as one of the oldest within Carex. The diversification rate probably decreased over time in the whole subgenus. Geography seems to have played a primary role in the diversification of subg. Psyllophorae. Inferred divergence times imply a diversification scenario away from primary Gondwanan vicariance hypotheses and suggest long-distance dispersal-mediated allopatric diversification. Section Junciformes remained in Northern Patagonia since its divergence until Plio-Pleistocene glaciations. Andean orogeny appears to have acted as a northward corridor, which contrasts with the general pattern of North-to-South migration for temperate-adapted organisms. A striking niche conservatism characterizes the evolution of this section. Colonization of the SW Pacific took place on a single long-distance dispersal event from SA. The little ecological changes involved in the Benítez-Benítez et al. Biogeography of Carex Subg. Psyllophorae trans-Pacific disjunction imply the preadaptation of the group prior to the colonization of the SW Pacific. The high species number of the section results from simple accumulation of morphological changes (disparification), rather than shifts in ecological niche related to increased diversification rates (radiation).

Research paper thumbnail of Re-evaluating the presence of Carex microcarpa (Cyperaceae) in Italy based on herbarium material and DNA barcoding

Plant Biosystems, Apr 13, 2021

Carex microcarpa (sect. Rhynchocystis) is a Central Mediterranean endemic known from Corsica, Sar... more Carex microcarpa (sect. Rhynchocystis) is a Central Mediterranean endemic known from Corsica, Sardinia and the Tuscan archipelago, that has been also reported from scattered localities in mainland ...

Research paper thumbnail of Chorological news for Carex (Cyperaceae) in the Iberian Peninsula

Anales de biología, Jun 29, 2023

Se presentan diversas notas corológicas del género Carex para la península ibérica, que incluyen ... more Se presentan diversas notas corológicas del género Carex para la península ibérica, que incluyen novedades provinciales para cuatro especies (C. elata subsp. elata, C. demissa subsp. demissa, C. oedipostyla, C. sylvatica subsp. sylvatica) así como la confirmación provincial (no indicada en Flora iberica) de la presencia de tres taxónes. Proporcionamos asimismo la segunda cita nacional para Portugal de C. reuteriana subsp. mauritanica. Otras tres citas poseen interés corológico al constituir novedades comarcales y/o de sector biogeográfico, o bien segunda cita provincial. Cinco de las novedades revisten interés conservacionista por tratarse de especies o poblaciones amenazadas, incluidas en Listas Rojas y/o protegidas a nivel legal. Por último, hacemos referencia a la posible naturalización de C. pendula.

Research paper thumbnail of Revised lectotypification of Reseda glauca L. (Resedaceae )

Taxon, Oct 1, 2011

The currently accepted lectotype (Herb. Linn. No. 629.4, LINN) of Reseda glauca L. is identifiabl... more The currently accepted lectotype (Herb. Linn. No. 629.4, LINN) of Reseda glauca L. is identifiable as the related species, R. virgata Boiss. & Reuter. The specimen, collected by Löfling in central Spain, was not explicitly cited in Linnaeus's protologue, in contrast to a specimen (at UPS) collected by Burser in the Pyrenees and identifiable as R. glauca of usage. In accordance with Art. 9.10 of the ICBN, we reject the choice of 629.4 (LINN) as lectotype and we designate Burser's specimen as the lectotype of R. glauca L. in its place. This type choice maintains the traditional and current usage of this well-known and widely used Linnaean name.

Research paper thumbnail of <I>Carex modesti</I> (<I>Cyperaceae</I>), a new species from southern Tanzania

Research paper thumbnail of <i>Carex cespitosa</i>: reappraisal of its distribution in Europe

Willdenowia, Dec 5, 2014

BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access t... more BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access titles in the biological, ecological, and environmental sciences published by nonprofit societies, associations, museums, institutions, and presses.

Research paper thumbnail of Biogeography of Flowering Plants: A Case Study in Mignonettes (Resedaceae) and Sedges (Carex, Cyperaceae)

InTech eBooks, Mar 30, 2012

Research paper thumbnail of New Insights into the Systematics of the Schoenoxiphium Clade (<i>Carex</i>, Cyperaceae)

International Journal of Plant Sciences, May 1, 2017

Premise of research. The Schoenoxiphium clade (Carex, Cyperaceae) exhibits a high species diversi... more 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.

Research paper thumbnail of Two independent dispersals to the Southern Hemisphere to become the most widespread bipolar Carex species: biogeography of C. canescens (Cyperaceae)

Botanical Journal of the Linnean Society, Mar 1, 2017

About 30 plant species occur at high latitudes in both hemispheres, thus achieving a so-called bi... more About 30 plant species occur at high latitudes in both hemispheres, thus achieving a so-called bipolar distribution. Six of these species belong to Carex, of which just one, Carex canescens, occurs on two different landmasses in the Southern Hemisphere (South America and Oceania). The goals of this study are (1) to test the various hypotheses accounting for the bipolar disjunction of C. canescens and (2) to elucidate if C. canescens migrated twice from the Northern Hemisphere to the Southern Hemisphere or if it dispersed from South America to Oceania (or vice versa). We obtained and analysed DNA sequences from the nuclear internal and external transcribed spacers (ITS and ETS) and from the plastid 5′ trnK and rps16 introns from 57 populations of C. canescens spanning its bipolar range. We characterized the species distribution climatically by adding 1995 presence data points from the Global Biodiversity Information Facility. Our results suggest a Northern Hemisphere origin of C. canescens during the Pleistocene and two independent long distance-dispersal events to South America and Australia, by either direct dispersal or mountain-hopping. Long-distance dispersal appears to be the most widespread process resulting in the bipolar distribution of Carex spp.

Research paper thumbnail of Reconciling morphology and phylogeny allows an integrative taxonomic revision of the giant sedges of Carex section Rhynchocystis (Cyperaceae)

Botanical Journal of the Linnean Society, Jul 17, 2018

Research paper thumbnail of Is the diversification of Mediterranean Basin plant lineages coupled to karyotypic changes?

Plant Biology, Apr 3, 2017

The Mediterranean Basin region, home to 25,000 species of plants, is included in the worldwide li... more The Mediterranean Basin region, home to 25,000 species of plants, is included in the worldwide list of hotspots of biodiversity. Despite the indisputably important role of chromosome transitions in plant evolution and diversification, no reference study to date has dealt with the possible relationship between chromosome evolution and lineage diversification in the Mediterranean Basin.  Here we study patterns of diversification, patterns of chromosome number transition (either polyploidy or dysploidy), and the relationship between both for 14 Mediterranean Basin angiosperm lineages using previously published phylogenies.  We found a mixed pattern, with half of the lineages displaying a change in chromosome transition rates after the onset of the Mediterranean climate (six increase, one decrease) and the other half (six) experiencing constant rates of chromosome transitions through time. We have also found a heterogenous pattern regarding diversification rates, with lineages exhibiting moderate (five phylogenies) or low (six) initial diversification rates that either increased (six) or declined (five) through time. Our results reveal no clear link between diversification rates and chromosome number transition rates.  By promoting the formation of new habitats and driving the extinction of many species, the Mediterranean onset and the posterior Quaternary climatic oscillations could have been key for the establishment of new chromosomal variants in some plant phylogenies but not in others. While the biodiversity of the Mediterranean Basin may be partly influenced by the chromosomal diversity of its lineages, this study concludes that lineage diversification in the region is largely decoupled from karyotypic evolution.

Research paper thumbnail of Direct long-distance dispersal best explains the bipolar distribution of Carex arctogena (Carex sect. Capituligerae , Cyperaceae)

Journal of Biogeography, Apr 22, 2015

Aim The bipolar disjunction, a biogeographical pattern defined by taxa with a distribution at ver... more Aim The bipolar disjunction, a biogeographical pattern defined by taxa with a distribution at very high latitudes in both hemispheres (> 61° N; > 54° S), is only known to occur in about 30 vascular plant species. Our aim was to use the bipolar species Carex arctogena to test the four classic hypotheses proposed to explain this exceptional disjunction: convergent evolution, vicariance, mountain-hopping and direct long-distance dispersal. Location Arctic/boreal and temperate latitudes of both hemispheres. Methods A combination of molecular and bioclimatic data was used to test phylogeographical hypotheses in C. arctogena. Three chloroplast markers (atpF-atpH, matK and rps16) and the nuclear ITS region were sequenced for all species in Carex sections Capituligerae and Longespicatae; Carex rupestris, C. obtusata and Uncinia triquetra were used as outrgroups. Phylogenetic relationships, divergence-time estimates and biogeographical patterns were inferred using maximum likelihood, statistical parsimony and Bayesian inference. Results Carex sections Capituligerae and Longespicatae formed a monophyletic group that diverged during the late Miocene. Two main lineages of C. arctogena were inferred. Southern Hemisphere populations of C. arctogena shared the same haplotype as a widespread circumboreal lineage. Bioclimatic data shows that Southern and Northern Hemisphere populations currently differ in their ecological regimes. Main conclusions Two of the four hypotheses accounting for bipolar disjunctions may be rejected. Our results suggest that direct long-distance dispersal, probably southwards and mediated by birds, best explains the bipolar distribution of C. arctogena.

Research paper thumbnail of Geographical speciation related to Pleistocene range shifts in the western Mediterranean mountains (<i>Reseda</i> sect. <i>Glaucoreseda</i> , Resedaceae)

Taxon, Apr 1, 2010

Reseda sect. Glaucoreseda is a monophyletic group composed of five endemic tetraploid species wit... more Reseda sect. Glaucoreseda is a monophyletic group composed of five endemic tetraploid species with a disjunct distribution in the high mountains and plateaus of the Iberian Peninsula and Morocco. It was previously suggested that range shifts induced by Quaternary glaciations played an important role in the speciation of the group. We studied the evolution of R. sect. Glaucoreseda in order to infer historical range dynamics and speciation processes, and to understand current distributional patterns. Phylogeographic analyses were performed using nuclear ribosomal ITS and plastid trnL-F and rps16 sequences. Cloning of additive ITS sequences was carried out to elucidate the origin of intra-individual polymorphisms. A dated phylogeny based on ITS and cpDNA (rbcL, matK, trnL-F) sequences was used to estimate divergence times of R. sect. Glaucoreseda. Time estimates using Penalized Likelihood analyses indicate a late Pleistocene diversification of R. sect. Glaucoreseda. Incomplete lineage sorting of ancestral polymorphisms due to recent divergence, rather than rampant hybridisation, is suggested as the main cause of the phylogenetic incongruence detected between nuclear and plastid datasets. Our results support the vicariance hypothesis for population disjunctions in the Iberian Peninsula, in which an ancestral, widespread species could have undergone differentiation by Quaternary interglacial fragmentation. In contrast, long-distance dispersal across the Strait of Gibraltar may have been involved in the colonisation of North African plateaus by R. battandieri.

Research paper thumbnail of A synopsis of the androgynous species of <i>Carex</i> subgenus <i>Vignea</i> (Cyperaceae) in South America

Botanical Journal of the Linnean Society, Mar 26, 2021

This is the first work of a series of thorough studies into the taxonomy and systematics of Carex... more This is the first work of a series of thorough studies into the taxonomy and systematics of Carex in South America. Here, we present the systematic placement, biogeographic insights, taxonomic accounts, formal typifications and summarized distributions for the 24 species of Carex subgenus Vignea with androgynous spikes in the continent. We performed a phylogenetic study using the barcode markers ETS, ITS and matK to check the placement of 22 of these species on a previous tree with > 1000 Carex spp. We examined > 600 specimens from 38 herbaria and conducted an exhaustive nomenclatural survey consulting all pertinent literature. South American androgynous species of subgenus Vignea are grouped in seven distinct lineages, corresponding with the same number of inferred colonizations. Most groups seem to have colonized South America during the Plio-Pleistocene, except for species of section Bracteosae, a local radiation that dates back to the Late Miocene. All colonizations by native species seem to have originated from North America. The two putatively introduced taxa are western Palaearctic species. An identification key is provided for the studied species. We make 19 new typifications and a new species (Carex pedicularis) is described.

Research paper thumbnail of Cladogenesis

Research paper thumbnail of Tracking gypsophily across the phylogeny: 3 study cases

To gain an evolutionary understanding of plant gypsophily, is essential to incorporate phylogeny ... more To gain an evolutionary understanding of plant gypsophily, is essential to incorporate phylogeny in the analyses. Here we present an overview of three different approaches that we are currently undertaking to tackle this issue. (I) we have selected 5 Iberian genera with gysophite or gypsovag species in which a fairly complete and reliable phylogeny is published (Ononis, Helianthemum, Chaenorrhinum, Reseda and Teucrium). In each of these 5 lineages we plan to explore the events of gypsophily and to evaluate the existence of preadaptations along the clades in terms of ionome. (II) Within the Ononis tridentata-fruticosa-rotundifolia clade, we intend to carry out Hyb-Seq taking the leaf and soil chemical composition into account. Among other biogegraphic and phylogenetic inferences, we are particularly interested on the comparison of the ionome of O. fruticosa populations growing in and out gypsum. (III)We plan to reconstruct the phylogeny of the genus Frankenia based on HybSeq, which comprises a relevant amount of halophyte, gypso-halophyte and gypsum species, particularly in Australia. This worldwide distributed genus is crucial for the understanding of chemical adaptations of gypso-halophytes, a poorly described functional group, but requires a taxonomic and phylogenetic clarification before further analysis. Approaches II and III will use the Angiosperms-353 kit (myBaits), which will allow integrating the results in further studies beyond our current particular purposes

Research paper thumbnail of plb12458-sup-0001-Supinfo

Research paper thumbnail of Dramatic impact of future climate change on the genetic diversity and distribution of ecologically relevant Western Mediterranean <i>Carex</i> (Cyperaceae)

PeerJ, May 31, 2022

Anticipating the evolutionary responses of species to ongoing climate change is essential to prop... more Anticipating the evolutionary responses of species to ongoing climate change is essential to propose effective management and conservation measures. The Western Mediterranean Basin constitutes one of the hotspots of biodiversity where the effects of climate change are expected to be more dramatic. Plant species with ecological relevance constitute ideal models to evaluate and predict the impact of climate change on ecosystems. Here we investigate these impacts through the spatio-temporal comparison of genetic diversity/structure (AFLPs), potential distribution under different future scenarios of climate change, and ecological space in two Western Mediterranean sister species of genus Carex. Both species are ecologically key in their riparian habitats, but display contrasting distribution patterns, with one widespread in the Iberian Peninsula and North Africa (C. reuteriana), while the other (C. panormitana) is a restricted, probably endangered, Central Mediterranean endemic. At present, we found a strong genetic structure driven by geography in both species, and lower values of genetic diversity and a narrower ecological space in C. panormitana than in C. reuteriana, while the allelic rarity was higher in the former than in C. reuteriana subspecies. Future projections predict an overall dramatic reduction of suitable areas for both species under all climate change scenarios, which could be almost total for C. panormitana. In addition, gene diversity was inferred to decrease in all taxa, with genetic structure reinforcing in C. reuteriana by the loss of admixture among populations. Our findings stress the need for a reassessment of C. panormitana conservation status under IUCN Red List criteria and the implementation of conservation measures.

Research paper thumbnail of Systematics of the Giant Sedges of Carex Sect. Rhynchocystis (Cyperaceae) in Macaronesia with Description of Two New Species

Systematic Botany, Aug 11, 2021

— Populations of Carex sect. Rhynchocystis (Cyperaceae) from the Macaronesian archipelagos (Azore... more — Populations of Carex sect. Rhynchocystis (Cyperaceae) from the Macaronesian archipelagos (Azores and Madeira) have traditionally been treated either as a variety of the widely distributed Western Palearctic C. pendula, or directly synonymized under it. However, recent phylogenetic studies have shown that Azorean populations of C. pendula display a certain degree of differentiation from mainland plants, while the phylogenetic relationships of Madeiran populations remain unclear. Here we perform an integrated systematic study focused on the Macaronesian populations of Carex sect. Rhynchocystis to elucidate their phylogenetic relationships and taxonomic status. We reconstructed a molecular phylogeny based on five DNA regions and conducted a multivariate morphological analysis. Divergence time estimates show that the Macaronesian populations can be traced back to a Plio-Pleistocene origin. Our results suggest that these island populations of C. pendula are better treated as two distinct species within Carex sect. Rhynchocystis (i.e. C. leviosa from the Azores and C. sequeirae from Madeira). We provide morphological characters to differentiate the new species from C. pendula s. s., detailed descriptions of the three taxa, a revised key for the entire section, as well as detailed analytical drawings of the two newly described species. We also perform a critical evaluation of the taxonomic diversity of Carex in the Azores and Madeira. Finally, we informally assessed the conservation status of the new species at a global scale under IUCN categories and criteria, resulting in the proposal of the categories Least Concern for C. leviosa and Critically Endangered for C. sequeirae.

Research paper thumbnail of Biogeography and systematics of <i>Carex</i> subgenus <i>Uncinia</i> (Cyperaceae): A unique radiation for the genus <i>Carex</i> in the Southern Hemisphere

Taxon, Feb 23, 2022

Carex subg. Uncinia (Cyperaceae) constitutes one of six currently recognized Carex subgenera. Thi... more Carex subg. Uncinia (Cyperaceae) constitutes one of six currently recognized Carex subgenera. This subgenus is mainly distributed on the American continent and in the Pacific region, and it is the only subgenus almost entirely absent from the Old World and primarily diversified in the Southern Hemisphere. It includes some of the few Carex species with clear epizoochoric traits: the representatives of C. sect. Uncinia possess utricles with an exserted and hooked rachilla that allows the diaspores to attach to feather or hair. We performed phylogenetic (ITS, ETS-1f, matK), biogeographic, and ancestral state reconstruction analyses to elucidate the systematic structure, origin and dispersal routes, and major morphological evolutionary patterns of the different lineages within the subgenus. Our phylogenetic reconstructions revealed that the subgenus comprises seven different clades that mostly match previously recognized sections. One of the clades, however, represents a new section described herein as C. sect. Wheelerianae. Unispicate lineages evolved repeatedly from ancestors bearing multispicate inflorescences, while the presence of a rachilla, often pictured as a plesiomorphy in Carex, seems to have developed four independent times in the evolution of C. subg. Uncinia. The origin of the subgenus This is the author manuscript accepted for publication and has undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record. Please cite this article as

Research paper thumbnail of An Evolutionary Study of Carex Subg. Psyllophorae (Cyperaceae) Sheds Light on a Strikingly Disjunct Distribution in the Southern Hemisphere, With Emphasis on Its Patagonian Diversification

Frontiers in Plant Science, Nov 8, 2021

Carex subgenus Psyllophorae is an engaging study group due to its early diversification compared ... more Carex subgenus Psyllophorae is an engaging study group due to its early diversification compared to most Carex lineages, and its remarkable disjunct distribution in four continents corresponding to three independent sections: sect. Psyllophorae in Western Palearctic, sect. Schoenoxiphium in Afrotropical region, and sect. Junciformes in South America (SA) and SW Pacific. The latter section is mainly distributed in Patagonia and the Andes, where it is one of the few Carex groups with a significant in situ diversification. We assess the role of historical geo-climatic events in the evolutionary history of the group, particularly intercontinental colonization events and diversification processes, with an emphasis on SA. We performed an integrative study using phylogenetic (four DNA regions), divergence times, diversification rates, biogeographic reconstruction, and bioclimatic niche evolution analyses. The crown age of subg. Psyllophorae (early Miocene) supports this lineage as one of the oldest within Carex. The diversification rate probably decreased over time in the whole subgenus. Geography seems to have played a primary role in the diversification of subg. Psyllophorae. Inferred divergence times imply a diversification scenario away from primary Gondwanan vicariance hypotheses and suggest long-distance dispersal-mediated allopatric diversification. Section Junciformes remained in Northern Patagonia since its divergence until Plio-Pleistocene glaciations. Andean orogeny appears to have acted as a northward corridor, which contrasts with the general pattern of North-to-South migration for temperate-adapted organisms. A striking niche conservatism characterizes the evolution of this section. Colonization of the SW Pacific took place on a single long-distance dispersal event from SA. The little ecological changes involved in the Benítez-Benítez et al. Biogeography of Carex Subg. Psyllophorae trans-Pacific disjunction imply the preadaptation of the group prior to the colonization of the SW Pacific. The high species number of the section results from simple accumulation of morphological changes (disparification), rather than shifts in ecological niche related to increased diversification rates (radiation).

Research paper thumbnail of Re-evaluating the presence of Carex microcarpa (Cyperaceae) in Italy based on herbarium material and DNA barcoding

Plant Biosystems, Apr 13, 2021

Carex microcarpa (sect. Rhynchocystis) is a Central Mediterranean endemic known from Corsica, Sar... more Carex microcarpa (sect. Rhynchocystis) is a Central Mediterranean endemic known from Corsica, Sardinia and the Tuscan archipelago, that has been also reported from scattered localities in mainland ...