Marcela Viviana Nicola | Instituto de Botánica Darwinion (IBODA) (original) (raw)

Papers by Marcela Viviana Nicola

Biological Journal of the Linnean Society, 2020

We performed an integrated phylogeographical and palaeoclimatic study of an early-diverging membe... more We performed an integrated phylogeographical and palaeoclimatic study of an early-diverging member of Asteraceae, Duseniella patagonica, endemic to Argentina. Chloroplast and nuclear markers were sequenced from 106 individuals belonging to 20 populations throughout the species range. We analysed genetic spatial distribution, diversity and structure, tested for range expansion, estimated divergence times, reconstructed ancestral areas and modelled present and past species distributions based on climatic data. Duseniella diverged from its sister genera during the Late/Middle Miocene. Its ancestral area included southern Monte plus eastern and central Patagonia. A vicariant event separated Monte and Patagonian clades during the Plio-Pleistocene. This would have involved unfavourable climate, soil, elevation, volcanism and/or other geomorphological processes between 40 and 43.5°S, in the sourroundings of the Somuncura plateau. Each clade possesses its own haplotypes and nucleotypes. Two populations, one in southern Monte and the other in eastern Patagonia, contain the highest diversity and exclusive haplotypes, representing hypothetical ancestral refugia. Northern Monte and southern Patagonian populations show low to null genetic diversity, being the most recently colonized areas. Climatic models indicate that winter temperature influenced the distribution of Duseniella, with an increase in probability of occurrence during colder periods, thus enabling diversification during glacial episodes.

Science 365(6448): 22-23, 2019

We asked young scientists this question: In exactly six words, what is the secret to preventing b... more We asked young scientists this question: In exactly six words, what is the secret to preventing burnout? In their succinct responses, scientists from around the world suggested ways to prioritize breaks, focus on the positive, and fi nd inspiration in work, hobbies, and community. Our respondents urged researchers facing burnout to take care of themselves, whether that means setting boundaries or giving themselves permission to splurge.

Molecular Phylogenetics and Evolution 136: 164-182, 2019

Congruence among different sources of data is highly desirable in phylogenetic analyses. However,... more Congruence among different sources of data is highly desirable in phylogenetic analyses. However, plastid and nuclear DNA may record different evolutionary processes such that incongruence among results from these sources can help unravel complex evolutionary histories. That is the case of Nassauvia subgenus Strongyloma (Asteraceae), a taxon with five putative species distributed in the southern Andes and Patagonian steppe. Morphometric and phylogeographic information cast doubt on the integrity of its species, and previous molecular data even questioned the monophyly of the subgenus. We tested those questions using plastid and nuclear DNA sequences by the application of different methods such as phylogenetic trees, networks, a test of genealogical sorting, an analysis of population structure, calibration of the trees, and hybridization test, assembling non-synchronous incongruent results at subgenus and species levels in a single reconstruction. The integration of our molecular analyses and previous taxonomic, morphological, and molecular studies support subgenus Strongyloma as a monophyletic group. However, the topology of the nuclear trees and the evidence of polyploids within subgenus Nassauvia, suggest a hypothetical origin and initial radiation of Nassauvia related to an ancient hybridization event that occurred around 17–6.3 Myr ago near the Andes in west-central Patagonia. Plastid data suggest a recent diversification within subgenus Strongyloma, at most 9.8 Myr ago, towards the Patagonian steppe east of the Andes. These processes cause phylogenies to deviate from the species tree since each putative species lack exclusive ancestry. The non-monophyly of its species using both plastid and nuclear data is caused mainly by incomplete lineage sorting occurred since the Miocene. The final uplift of the Andes and Pliocene-Pleistocene glacial-interglacial and its consequences on the landscape and climate structured the genetic composition of this group of plants in the Patagonian steppe. The molecular data presented here agree with previous morphological studies, in that the five putative species typically accepted in this subgenus are not independent taxa. This study emphasizes that adding more than one sequence per species, not combining data with dissimilar inheritance patterns without first performed incongruence tests, exploring data through different methodologies, considering the timing of events, and searching for the causes of poorly resolved and/or incongruent phylogenies help to reveal complex biological underlying processes, which might otherwise remain hidden.

Science 361(6397):24-26, 2018

We asked young scientists this question: How do broad interests benefit your science? Scientists ... more We asked young scientists this question: How do broad interests benefit your science? Scientists with a variety of hobbies responded that their extracurricular activities have enhanced a wide range of skills, from creativity to communication to resilience. Many also mentioned the value of clearing their minds and relaxing. Follow NextGen and share your own hobbies on Twitter with #NextGenSci.

Phytotaxa 338(2), 2018

During the revision of Viola for the Flora of Argentina project we detected names which need an e... more During the revision of Viola for the Flora of Argentina project we detected names which need an exhaustive nomenclatural and taxonomic study. As a result of our analysis 43 lectotypes and three neotypes are designated for accepted names and synonyms of the genus as currently recognised by the present authors. Moreover, we encountered a nomen nudum, and present here a new combination and five new synonyms.

During the revision of Siphocampylus for the Flora of Argentina, we detected names which need lec... more During the revision of Siphocampylus for the Flora of Argentina, we detected names which need lectotypification. As a
result of our analysis of original materials and protologues, lectotypes are designated for the following names: S. fiebrigii
var. intermedius, S. foliosus, S. foliosus var. minor, S. lorentzii, S. nemoralis, S. nemoralis var. grisebachii, S. nemoralis fo.
hieronymi, S. orbignianus, and S. verticillatus.

During the revision of Siphocampylus for the Flora of Argentina, we detected names which need lec... more During the revision of Siphocampylus for the Flora of Argentina, we detected names which need lectotypification. As a
result of our analysis of original materials and protologues, lectotypes are designated for the following names: S. fiebrigii
var. intermedius, S. foliosus, S. foliosus var. minor, S. lorentzii, S. nemoralis, S. nemoralis var. grisebachii, S. nemoralis fo.
hieronymi, S. orbignianus, and S. verticillatus.

Phytotaxa, 2015

ABSTRACT We describe a new species of Sicydium endemic to Argentina. Relationships and difference... more ABSTRACT We describe a new species of Sicydium endemic to Argentina. Relationships and differences with morphologically and geographically closest species are discussed, including a key for material with staminate flowers to all species of Sicydium, and an illustration of the new species.

We describe and illustrate Mastigostyla coronata, a new species of Iridaceae from the high Andes ... more We describe and illustrate Mastigostyla coronata, a new species of Iridaceae from the high Andes of Jujuy (Argentina), morphologically similar to Mastigostyla vargasii. The inclusion of this new species in Mastigostyla is supported by a phylogenetic analysis based on plastid markers. We also present a morphological comparison among the subacaulescent species of Mastigostyla (including Cardenanthus), and a key to those species.

Phytotaxa, 2015

We describe a new species of Sicydium endemic to Argentina. Relationships and differences with mo... more We describe a new species of Sicydium endemic to Argentina. Relationships and differences with morphologically and geographically closest species are discussed, including a key for material with staminate flowers to all species of Sicydium, and an illustration of the new species.

Se proponen tres nuevas combinaciones en Oriastrum: Oriastrum minutum de Argentina y Chile y O. s... more Se proponen tres nuevas combinaciones en Oriastrum: Oriastrum minutum de Argentina y Chile y O. stuebelii var. abbreviatum y O. stuebelii var. argentinum de Argentina. Se cita a O. tontalensis como nuevo sinónimo de O. pulvinatum var. polymallum y a O. famatinae y O. stuebelii var. cryptum como nuevos sinónimos de O. stuebelii var. argentinum. Se designan nueve lectotipos para: Aldunatea chilensis, A. gnaphalioides, A. lycopodioides, Carmelita formosa, Chaetanthera stuebelii var. argentina, C. villosa, Egania acerosa, E. dioica y Tylloma limbatum. Adicionalmente, se incluyen ilustraciones de filarios y hojas de O. pulvinatum var. polymallum y O. tontalensis y una tabla comparativa de los caracteres diagnósticos de las variedades de O. stuebelii y O. famatinae.

The new genus Kellochloa is proposed, on the basis of morphological and molecular characters, in ... more The new genus Kellochloa is proposed, on the basis of morphological and molecular characters, in order to include two North American species of Panicum s.l., previously classified in sect. Verrucosa: P. brachyanthum and P. verrucosum. Both species are annual, with decumbent culms branching divaricately at the lower nodes, and erect culms with terminal and axillary inflorescences, with pilose spikelets, lower glume 1/6 to 1/4 the length of the spikelet, upper glume and lower lemma subequal, 3–5-nerved, the lower anthecium reduced to the lower lemma, and upper anthecium indurate, with bicellular microhairs and simple papillae evenly distributed all over the lemma and palea. Molecular phylogenetic studies, analyzing plastid ndhF and rpoA sequences, confirmed that these morphological characters are differencial. The phylogenetic position and taxonomic features of the new genus are established and compared with Panicum s.str. and other taxa of the Sacciolepis-Trichanthecium clade. Full synonymies and descriptions, a distribution map, illustrations of both species, and a key are provided. Two new combinations are proposed. In addition, four African ungrouped species of Panicum s.l. were, for the first time, included in the phylogenetic analysis in order to analyze their relationship with the new genus and its positions in the Sacciolepis-Trichanthecium clade.

We describe a new species of Sicydium endemic to Argentina. Relationships and differences with mo... more We describe a new species of Sicydium endemic to Argentina. Relationships and differences with morphologically and geographically closest species are discussed, including a key for material with staminate flowers to all species of Sicydium, and an illustration of the new species.

The Patagonian steppe is an immense, cold, arid region, yet phylogeographical-ly understudied. Na... more The Patagonian steppe is an immense, cold, arid region, yet phylogeographical-ly understudied. Nassauviasubgen. Strongyloma is a characteristic element of the steppe, exhibiting a continuum of morphological variation. This taxon pro-vides a relevant phylogeographical model not only to understand how past environmental changes shaped the genetic structure of its populations, but also to explore phylogeographical scenarios at the large geographical scale of the Patagonian steppe. Here, we (1) assess demographic processes and historical events that shaped current geographic patterns of haplotypic diversity; (2) ana-lyze hypotheses of isolation in refugia, fragmentation of populations, and/or colonization of available areas during Pleistocene glaciations; and (3) model extant and palaeoclimatic distributions to support inferred phylogeographical patterns. Chloroplast intergenic spacers, rpl32–trnL and trnQ–5´rps16, were sequenced for 372 individuals from 63 populations. Nested clade analysis,
analyses of molecular variance, and neutrality tests were performed to assess genetic structure and range expansion. The present potential distribution was modelled and projected onto a last glacial maximum (LGM) model. Of 41
haplotypes observed, ten were shared among populations associated with differ-ent morphological variants. Populations with highest haplotype diversity and private haplotypes were found in central-western and south-eastern Patagonia, consistent with long-term persistence in refugia during Pleistocene. Palaeomod-elling suggested a shift toward the palaeoseashore during LGM; new available areas over the exposed Atlantic submarine platform were colonized during gla-ciations with postglacial retraction of populations. A scenario of fragmentation and posterior range expansion may explain the observed patterns in the center of the steppe, which is supported by palaeomodelling. Northern Patagonian populations were isolated from southern populations by the Chubut and the Deseado river basins during glaciations. Pleistocene glaciations indirectly
impacted the distribution, demography, and diversification of subgen. Strongy-loma through decreased winter temperatures and water availability in different areas of its range.

El presente tratamiento incluye una revision taxonómica de las especies de Paspalum grupo Gardner... more El presente tratamiento incluye una revision taxonómica de las especies de Paspalum grupo Gardneriana. Dentro de este grupo se consideran siete especies, caracterizadas por incluir plantas anuales o perennes, con espiguillas usualmente obovoides, gluma superior ausente o reducida y antecio superior endurecido y marcadamente papiloso, con papilas verrugosas en toda su superficie. Se incluye una clave de las especies, descripciones, ilustraciones y fotos de los antecios, junto con un análisis de la relación del grupo dentro del género Paspalum. Se consideran dentro del grupo las siguientes especies: Paspalum burchellii, P. delicatum, P. gardnerianum, P. nudatum, P. pictum, P. reduncum y P. subsesquiglume. Se designan lectotipos para P. burchellii, P. connectens, P. reduncum y P. subsesquiglume; P. gemmosum es sinónimo de P. subsesquiglume.

Morphological variation among the five species of Nassauvia subgenus Strongyloma was assessed thr... more Morphological variation among the five species of Nassauvia subgenus Strongyloma was assessed through statistical analyses of morphometric traits in populations throughout the southern Andean-Patagonian region. Uni-and multivariate analyses were used to identify patterns of morphological variation in relation to geography. Additionally, species distribution modeling was implemented to relate these patterns to climatic conditions. No well-defined groups could be recovered through multivariate analyses, although we observed some geographic structure. Latitudinal variation was found in leaves, phyllaries and cypselas, with a cline towards the south, where these structures become shorter and wider. Towards the east, the number of flowers per capitulum decreases, and abaxial corolla lips and cypselas become narrower and shorter. Distribution modeling showed several areas of contact and a large overlap of suitable conditions for more than one species, which is mainly related to the mean temperature of winter. Despite an association between morphological variation with geography and climate, actual geographic distributions of the putative species did not entirely match the clinal pattern of morphology, geography, and climate. Further genetic analyses are still needed to identify the probable processes that led to the complex patterns of observed variation.

A new apetalous species of Minuartia from the high Andes of northwestern Argentina, M. altoandina... more A new apetalous species of Minuartia from the high Andes of northwestern Argentina, M. altoandina, is here described and illustrated. At first sight, M. altoandina is morphologically very similar to the European M. sedoides because of the absence of petals and ciliate leaf margin with narrow hyaline teeth; however, from a biogeographical point of view, it will probably be related to the North American M. rossii complex through the morphology of M. austromontana.

The taxonomic position of a new family of flowering plants recently described, Pycnanthaceae Rave... more The taxonomic position of a new family of flowering plants recently described, Pycnanthaceae Ravenna, is here discussed; as a result of comparison of type material, this new taxon is placed in the synonymy of the genus Malaxis within the Orchidaceae. A list of species of Malaxis growing in Argentina is provided, as well as a key to differentiate them.

Aim An integrative study of the endemic, yet ubiquitous, Patagonian shrub Mulinum spinosum (Apiac... more Aim An integrative study of the endemic, yet ubiquitous, Patagonian shrub Mulinum spinosum (Apiaceae) was performed: (1) to assess the historical processes that influenced its geographical pattern of genetic variation; (2) to test hypotheses of its survival in situ or in glacial refugia during glacial cycles; and (3) to model its extant and palaeoclimatic distributions to assess support for the phylogeographical patterns recovered.

Biological Journal of the Linnean Society, 2020

We performed an integrated phylogeographical and palaeoclimatic study of an early-diverging membe... more We performed an integrated phylogeographical and palaeoclimatic study of an early-diverging member of Asteraceae, Duseniella patagonica, endemic to Argentina. Chloroplast and nuclear markers were sequenced from 106 individuals belonging to 20 populations throughout the species range. We analysed genetic spatial distribution, diversity and structure, tested for range expansion, estimated divergence times, reconstructed ancestral areas and modelled present and past species distributions based on climatic data. Duseniella diverged from its sister genera during the Late/Middle Miocene. Its ancestral area included southern Monte plus eastern and central Patagonia. A vicariant event separated Monte and Patagonian clades during the Plio-Pleistocene. This would have involved unfavourable climate, soil, elevation, volcanism and/or other geomorphological processes between 40 and 43.5°S, in the sourroundings of the Somuncura plateau. Each clade possesses its own haplotypes and nucleotypes. Two populations, one in southern Monte and the other in eastern Patagonia, contain the highest diversity and exclusive haplotypes, representing hypothetical ancestral refugia. Northern Monte and southern Patagonian populations show low to null genetic diversity, being the most recently colonized areas. Climatic models indicate that winter temperature influenced the distribution of Duseniella, with an increase in probability of occurrence during colder periods, thus enabling diversification during glacial episodes.

Science 365(6448): 22-23, 2019

We asked young scientists this question: In exactly six words, what is the secret to preventing b... more We asked young scientists this question: In exactly six words, what is the secret to preventing burnout? In their succinct responses, scientists from around the world suggested ways to prioritize breaks, focus on the positive, and fi nd inspiration in work, hobbies, and community. Our respondents urged researchers facing burnout to take care of themselves, whether that means setting boundaries or giving themselves permission to splurge.

Molecular Phylogenetics and Evolution 136: 164-182, 2019

Congruence among different sources of data is highly desirable in phylogenetic analyses. However,... more Congruence among different sources of data is highly desirable in phylogenetic analyses. However, plastid and nuclear DNA may record different evolutionary processes such that incongruence among results from these sources can help unravel complex evolutionary histories. That is the case of Nassauvia subgenus Strongyloma (Asteraceae), a taxon with five putative species distributed in the southern Andes and Patagonian steppe. Morphometric and phylogeographic information cast doubt on the integrity of its species, and previous molecular data even questioned the monophyly of the subgenus. We tested those questions using plastid and nuclear DNA sequences by the application of different methods such as phylogenetic trees, networks, a test of genealogical sorting, an analysis of population structure, calibration of the trees, and hybridization test, assembling non-synchronous incongruent results at subgenus and species levels in a single reconstruction. The integration of our molecular analyses and previous taxonomic, morphological, and molecular studies support subgenus Strongyloma as a monophyletic group. However, the topology of the nuclear trees and the evidence of polyploids within subgenus Nassauvia, suggest a hypothetical origin and initial radiation of Nassauvia related to an ancient hybridization event that occurred around 17–6.3 Myr ago near the Andes in west-central Patagonia. Plastid data suggest a recent diversification within subgenus Strongyloma, at most 9.8 Myr ago, towards the Patagonian steppe east of the Andes. These processes cause phylogenies to deviate from the species tree since each putative species lack exclusive ancestry. The non-monophyly of its species using both plastid and nuclear data is caused mainly by incomplete lineage sorting occurred since the Miocene. The final uplift of the Andes and Pliocene-Pleistocene glacial-interglacial and its consequences on the landscape and climate structured the genetic composition of this group of plants in the Patagonian steppe. The molecular data presented here agree with previous morphological studies, in that the five putative species typically accepted in this subgenus are not independent taxa. This study emphasizes that adding more than one sequence per species, not combining data with dissimilar inheritance patterns without first performed incongruence tests, exploring data through different methodologies, considering the timing of events, and searching for the causes of poorly resolved and/or incongruent phylogenies help to reveal complex biological underlying processes, which might otherwise remain hidden.

Science 361(6397):24-26, 2018

We asked young scientists this question: How do broad interests benefit your science? Scientists ... more We asked young scientists this question: How do broad interests benefit your science? Scientists with a variety of hobbies responded that their extracurricular activities have enhanced a wide range of skills, from creativity to communication to resilience. Many also mentioned the value of clearing their minds and relaxing. Follow NextGen and share your own hobbies on Twitter with #NextGenSci.

Phytotaxa 338(2), 2018

During the revision of Viola for the Flora of Argentina project we detected names which need an e... more During the revision of Viola for the Flora of Argentina project we detected names which need an exhaustive nomenclatural and taxonomic study. As a result of our analysis 43 lectotypes and three neotypes are designated for accepted names and synonyms of the genus as currently recognised by the present authors. Moreover, we encountered a nomen nudum, and present here a new combination and five new synonyms.

During the revision of Siphocampylus for the Flora of Argentina, we detected names which need lec... more During the revision of Siphocampylus for the Flora of Argentina, we detected names which need lectotypification. As a
result of our analysis of original materials and protologues, lectotypes are designated for the following names: S. fiebrigii
var. intermedius, S. foliosus, S. foliosus var. minor, S. lorentzii, S. nemoralis, S. nemoralis var. grisebachii, S. nemoralis fo.
hieronymi, S. orbignianus, and S. verticillatus.

During the revision of Siphocampylus for the Flora of Argentina, we detected names which need lec... more During the revision of Siphocampylus for the Flora of Argentina, we detected names which need lectotypification. As a
result of our analysis of original materials and protologues, lectotypes are designated for the following names: S. fiebrigii
var. intermedius, S. foliosus, S. foliosus var. minor, S. lorentzii, S. nemoralis, S. nemoralis var. grisebachii, S. nemoralis fo.
hieronymi, S. orbignianus, and S. verticillatus.

Phytotaxa, 2015

ABSTRACT We describe a new species of Sicydium endemic to Argentina. Relationships and difference... more ABSTRACT We describe a new species of Sicydium endemic to Argentina. Relationships and differences with morphologically and geographically closest species are discussed, including a key for material with staminate flowers to all species of Sicydium, and an illustration of the new species.

We describe and illustrate Mastigostyla coronata, a new species of Iridaceae from the high Andes ... more We describe and illustrate Mastigostyla coronata, a new species of Iridaceae from the high Andes of Jujuy (Argentina), morphologically similar to Mastigostyla vargasii. The inclusion of this new species in Mastigostyla is supported by a phylogenetic analysis based on plastid markers. We also present a morphological comparison among the subacaulescent species of Mastigostyla (including Cardenanthus), and a key to those species.

Phytotaxa, 2015

We describe a new species of Sicydium endemic to Argentina. Relationships and differences with mo... more We describe a new species of Sicydium endemic to Argentina. Relationships and differences with morphologically and geographically closest species are discussed, including a key for material with staminate flowers to all species of Sicydium, and an illustration of the new species.

Se proponen tres nuevas combinaciones en Oriastrum: Oriastrum minutum de Argentina y Chile y O. s... more Se proponen tres nuevas combinaciones en Oriastrum: Oriastrum minutum de Argentina y Chile y O. stuebelii var. abbreviatum y O. stuebelii var. argentinum de Argentina. Se cita a O. tontalensis como nuevo sinónimo de O. pulvinatum var. polymallum y a O. famatinae y O. stuebelii var. cryptum como nuevos sinónimos de O. stuebelii var. argentinum. Se designan nueve lectotipos para: Aldunatea chilensis, A. gnaphalioides, A. lycopodioides, Carmelita formosa, Chaetanthera stuebelii var. argentina, C. villosa, Egania acerosa, E. dioica y Tylloma limbatum. Adicionalmente, se incluyen ilustraciones de filarios y hojas de O. pulvinatum var. polymallum y O. tontalensis y una tabla comparativa de los caracteres diagnósticos de las variedades de O. stuebelii y O. famatinae.

The new genus Kellochloa is proposed, on the basis of morphological and molecular characters, in ... more The new genus Kellochloa is proposed, on the basis of morphological and molecular characters, in order to include two North American species of Panicum s.l., previously classified in sect. Verrucosa: P. brachyanthum and P. verrucosum. Both species are annual, with decumbent culms branching divaricately at the lower nodes, and erect culms with terminal and axillary inflorescences, with pilose spikelets, lower glume 1/6 to 1/4 the length of the spikelet, upper glume and lower lemma subequal, 3–5-nerved, the lower anthecium reduced to the lower lemma, and upper anthecium indurate, with bicellular microhairs and simple papillae evenly distributed all over the lemma and palea. Molecular phylogenetic studies, analyzing plastid ndhF and rpoA sequences, confirmed that these morphological characters are differencial. The phylogenetic position and taxonomic features of the new genus are established and compared with Panicum s.str. and other taxa of the Sacciolepis-Trichanthecium clade. Full synonymies and descriptions, a distribution map, illustrations of both species, and a key are provided. Two new combinations are proposed. In addition, four African ungrouped species of Panicum s.l. were, for the first time, included in the phylogenetic analysis in order to analyze their relationship with the new genus and its positions in the Sacciolepis-Trichanthecium clade.

We describe a new species of Sicydium endemic to Argentina. Relationships and differences with mo... more We describe a new species of Sicydium endemic to Argentina. Relationships and differences with morphologically and geographically closest species are discussed, including a key for material with staminate flowers to all species of Sicydium, and an illustration of the new species.

The Patagonian steppe is an immense, cold, arid region, yet phylogeographical-ly understudied. Na... more The Patagonian steppe is an immense, cold, arid region, yet phylogeographical-ly understudied. Nassauviasubgen. Strongyloma is a characteristic element of the steppe, exhibiting a continuum of morphological variation. This taxon pro-vides a relevant phylogeographical model not only to understand how past environmental changes shaped the genetic structure of its populations, but also to explore phylogeographical scenarios at the large geographical scale of the Patagonian steppe. Here, we (1) assess demographic processes and historical events that shaped current geographic patterns of haplotypic diversity; (2) ana-lyze hypotheses of isolation in refugia, fragmentation of populations, and/or colonization of available areas during Pleistocene glaciations; and (3) model extant and palaeoclimatic distributions to support inferred phylogeographical patterns. Chloroplast intergenic spacers, rpl32–trnL and trnQ–5´rps16, were sequenced for 372 individuals from 63 populations. Nested clade analysis,
analyses of molecular variance, and neutrality tests were performed to assess genetic structure and range expansion. The present potential distribution was modelled and projected onto a last glacial maximum (LGM) model. Of 41
haplotypes observed, ten were shared among populations associated with differ-ent morphological variants. Populations with highest haplotype diversity and private haplotypes were found in central-western and south-eastern Patagonia, consistent with long-term persistence in refugia during Pleistocene. Palaeomod-elling suggested a shift toward the palaeoseashore during LGM; new available areas over the exposed Atlantic submarine platform were colonized during gla-ciations with postglacial retraction of populations. A scenario of fragmentation and posterior range expansion may explain the observed patterns in the center of the steppe, which is supported by palaeomodelling. Northern Patagonian populations were isolated from southern populations by the Chubut and the Deseado river basins during glaciations. Pleistocene glaciations indirectly
impacted the distribution, demography, and diversification of subgen. Strongy-loma through decreased winter temperatures and water availability in different areas of its range.

El presente tratamiento incluye una revision taxonómica de las especies de Paspalum grupo Gardner... more El presente tratamiento incluye una revision taxonómica de las especies de Paspalum grupo Gardneriana. Dentro de este grupo se consideran siete especies, caracterizadas por incluir plantas anuales o perennes, con espiguillas usualmente obovoides, gluma superior ausente o reducida y antecio superior endurecido y marcadamente papiloso, con papilas verrugosas en toda su superficie. Se incluye una clave de las especies, descripciones, ilustraciones y fotos de los antecios, junto con un análisis de la relación del grupo dentro del género Paspalum. Se consideran dentro del grupo las siguientes especies: Paspalum burchellii, P. delicatum, P. gardnerianum, P. nudatum, P. pictum, P. reduncum y P. subsesquiglume. Se designan lectotipos para P. burchellii, P. connectens, P. reduncum y P. subsesquiglume; P. gemmosum es sinónimo de P. subsesquiglume.

Morphological variation among the five species of Nassauvia subgenus Strongyloma was assessed thr... more Morphological variation among the five species of Nassauvia subgenus Strongyloma was assessed through statistical analyses of morphometric traits in populations throughout the southern Andean-Patagonian region. Uni-and multivariate analyses were used to identify patterns of morphological variation in relation to geography. Additionally, species distribution modeling was implemented to relate these patterns to climatic conditions. No well-defined groups could be recovered through multivariate analyses, although we observed some geographic structure. Latitudinal variation was found in leaves, phyllaries and cypselas, with a cline towards the south, where these structures become shorter and wider. Towards the east, the number of flowers per capitulum decreases, and abaxial corolla lips and cypselas become narrower and shorter. Distribution modeling showed several areas of contact and a large overlap of suitable conditions for more than one species, which is mainly related to the mean temperature of winter. Despite an association between morphological variation with geography and climate, actual geographic distributions of the putative species did not entirely match the clinal pattern of morphology, geography, and climate. Further genetic analyses are still needed to identify the probable processes that led to the complex patterns of observed variation.

A new apetalous species of Minuartia from the high Andes of northwestern Argentina, M. altoandina... more A new apetalous species of Minuartia from the high Andes of northwestern Argentina, M. altoandina, is here described and illustrated. At first sight, M. altoandina is morphologically very similar to the European M. sedoides because of the absence of petals and ciliate leaf margin with narrow hyaline teeth; however, from a biogeographical point of view, it will probably be related to the North American M. rossii complex through the morphology of M. austromontana.

The taxonomic position of a new family of flowering plants recently described, Pycnanthaceae Rave... more The taxonomic position of a new family of flowering plants recently described, Pycnanthaceae Ravenna, is here discussed; as a result of comparison of type material, this new taxon is placed in the synonymy of the genus Malaxis within the Orchidaceae. A list of species of Malaxis growing in Argentina is provided, as well as a key to differentiate them.

Aim An integrative study of the endemic, yet ubiquitous, Patagonian shrub Mulinum spinosum (Apiac... more Aim An integrative study of the endemic, yet ubiquitous, Patagonian shrub Mulinum spinosum (Apiaceae) was performed: (1) to assess the historical processes that influenced its geographical pattern of genetic variation; (2) to test hypotheses of its survival in situ or in glacial refugia during glacial cycles; and (3) to model its extant and palaeoclimatic distributions to assess support for the phylogeographical patterns recovered.

Flora Argentina: flora vascular de la República Argentina, 2019

Tratamiento taxonómico de Siphocampylus (Campanulaceae) para la Flora Argentina. Taxonomic treatm... more Tratamiento taxonómico de Siphocampylus (Campanulaceae) para la Flora Argentina. Taxonomic treatment of Siphocampylus (Campanulaceae) for the Flora of Argentina.

In book: Flora Argentina: flora vascular de la República Argentina. Chapter: Tomo 17. Publisher: Estudio Sigma. Editors: Zuloaga, Belgrano, 2017

Tratamiento taxonómico de Viola (Violaceae) para la Flora Argentina. Taxonomic treatment of Viola... more Tratamiento taxonómico de Viola (Violaceae) para la Flora Argentina. Taxonomic treatment of Viola (Violaceae) for the Flora of Argentina.

In book: Flora Argentina: flora vascular de la República Argentina. Chapter: Tomo 17. Publisher: Estudio Sigma. Editors: Zuloaga, Belgrano, 2017

Tratamiento taxonómico de Hybanthus (Violaceae) para la Flora Argentina. Taxonomic treatment of H... more Tratamiento taxonómico de Hybanthus (Violaceae) para la Flora Argentina. Taxonomic treatment of Hybanthus (Violaceae) for the Flora of Argentina.

In book: Flora Argentina: flora vascular de la República Argentina. Chapter: Tomo 17. Publisher: Estudio Sigma. Editors: Zuloaga, Belgrano, 2017

Tratamiento taxonómico de Pombalia (Violaceae) para la Flora Argentina. Taxonomic treatment of Po... more Tratamiento taxonómico de Pombalia (Violaceae) para la Flora Argentina. Taxonomic treatment of Pombalia (Violaceae) for the Flora of Argentina.

In book: Flora Argentina: flora vascular de la República Argentina. Chapter: Tomo 17. Publisher: Estudio Sigma. Editors: Zuloaga, Belgrano, 2017

Tratamiento taxonómico de Anchietea (Violaceae) para la Flora Argentina. Taxonomic treatment of A... more Tratamiento taxonómico de Anchietea (Violaceae) para la Flora Argentina. Taxonomic treatment of Anchietea (Violaceae) for the Flora of Argentina.

Flora Argentina. Volumen 7. Tomo 2. Capítulo: Mutisieae, 2014

Taxonomic treatment of Chaetanthera (Asteraceae) for the "Flora Argentina".

Flora Argentina. Volumen 7. Tomo 2. Capítulo: Mutisieae, 2014

Taxonomic treatment of Oriastrum Poepp. (Asteraceae) for the "Flora Argentina".