Areas Of Southern South America Research Articles

Maize consumption out of the production areas in southern South America (Norpatagonia, Argentina): Occasional production, foreigner consumers, or exchange?

This paper discusses the maize consumption record among hunter-gatherers outside assumed production areas in northeastern Patagonia. We evaluated if this anomalous record is the result of occasional events of local production/consumption; the transport of the microremains in the teeth of individuals after consuming maize in non-local production areas; or the local consumption of maize after its transport/exchange from production areas. Archaeobotanical results showed that analyzed individuals, including maize-consumers, mainly consumed local wild plants. Maize was not cultivated locally, and its consumption was unusual but not extraordinary in northeastern Patagonia. Oxygen isotope values of analyzed individuals are strongly compatible with local water sources, which imply that the mobility range of them must have not exceeded extra-Andean North Patagonia. For this reason, the most plausible explanation for the presence of maize in the local archaeological record is that this plant to have entered northeastern Patagonia through exchange, probably from southern Andes (central Chile or central-west Argentina).

Stratigraphy, provenance, and timing of Neogene sedimentation in the western Valdés Basin, Patagonia. Accurate paleogeographic reconstructions as a key piece for andean-passive margin integration

With the aim to better understand the timing and geological evolution of the late Cenozoic stratigraphic record of the onshore, western Valdés Basin in northeast Chubut province (Patagonia, Argentina), we perform sedimentological, stratigraphic, and zircon U–Pb geochronologic analyses. The study includes the terrestrial Early Miocene Trelew Member of the Sarmiento Formation, the shallow marine Early Miocene Gaiman Formation, the shallow marine to estuarine Late Miocene Puerto Madryn Formation, and the Plesitocene fluvial conglomerates of the Rodados Patagónicos. Based on our data set, together with the recognition of relevant stratigraphic surfaces, we divide the succession into stratigraphically bounded units and define three cycles of sedimentation. The Lower Cycle rests on top of Surface 1, which comprise a long hiatus including the entire Oligocene Epoch. This cycle is in turn divided into two subunits separated by the transgressive, ravinement Surface 2. The Lower Cycle is separated from the overlying Middle Cycle (=Puerto Madryn Formation) by the flat and regionally extensive Surface 3. Finally, the latter is separated from the Upper Cycle (=Rodados Patagónicos) by Surface 4, a complex surface at the base of gravel deposits forming several terrace levels. Maximum depositional ages calculated from 10 zircon U–Pb samples indicate the succession between surface 1 and 4 extends from 21.5 to 2.7 Ma (Aquitanian-Piacenzian). The Lower Cycle is restricted to the 21.5–16 Ma interval (Aquitanian-Burdigalian); the Middle Cycle between 12 and 2.7 Ma (latest Serravalian-Piacenzian), with most of the new and previous ages clustering in the Tortonian; whereas the Upper Cycle is restricted to the Pleistocene. Although most of the analyzed sediments show fresh volcanic glass particles, older zircon ages are dominant, representing detrital components with a dominant peak of Permian-aged grains, with subordinated Devonian, Jurassic, Cretaceous, and Paleogene peaks. We interpret the analyzed succession as a condensed section compared to the offshore Valdés Basin depocenter area. Sedimentation in the study area was controlled by periods of slow subsidence, probably related to thermal subsidence and sediment compaction in the depocenter. Two main sources of sediments for the analyzed succession are envisaged: one represented by explosive volcanism located either in the Andes or in the North Patagonian Massif, the other through erosion of older rocks surrounding the North Patagonian Massif where late Paleozoic plutonic rocks are abundant. Particularly for the Middle and Upper cycles, an increase in Mesozoic contribution suggests erosion from sediments of the Cañadón Asfalto Basin. The new ages and stratigraphic analyses here reported are of major relevance for the integration of the onshore and offshore stratigraphies of the Valdés Basin which is key to connect the geologic evolution of the Andean and passive margin areas of southern South America. They are also of major relevance for the calibration of fossil communities, particularly for the abundant and diverse marine vertebrates preserved in the Burdigalian Gaiman Formation.

Implications of climate change for the distribution of the water opossum (Chironectes minimus): habitat loss and conservation opportunities

Climate change is expected to impact the geographic distribution of marsupial species in the near future and this impact is likely to be accentuated for the more specialist species. The water opossum (Chironectes minimus) is the only semiaquatic marsupial in the world and is considered naturally rare throughout its geographical range. In the present study, we use ecological niche modeling (ENM) to predict the potential impacts of climate change on the geographic distribution of water opossum throughout Neotropical Region at the end of twenty-first century. We assess the vulnerability of this species by calculating its biotic velocity and identifying potential areas for the conservation of the water opossum based on the changes in climatically stable areas over time. These areas were also compared with the availability of remnant forest in the future. The area of potential distribution of the water opossum is projected to decrease 22% in the future. Water opossum populations will be more vulnerable to climate change in central Brazil, toward the southern extreme, and in some regions of the Amazon biome. In the future, C. minimus may be unable to colonize some areas in southern South America and in Mexico. Climatically stable areas are found in Central America, northwestern and coastal areas in northern South America, and southeastern Brazil, however, most of these areas will not have remnant forest in the future. Climatically stable areas with remnant forest areas are an opportunity for the development of effective long-term conservation measures for C. minimus.

Paleoenvironmental changes in southern South American dust sources during the last glacial/interglacial transition: Evidence from clay mineral assemblages of the pampean loess

abstract Paleoclimatic reconstruction is critical for understanding present-day climate and for testing models that are currently used to predict future climatic changes. Different climatic conditions produce different clay minerals that can be recorded in geological archives providing insights into past weathering scenarios. However, in southern South America, scarce information is available from clay mineral assemblages found in aeolian sediments, such as loess deposits. Moreover, there is a lack of studies employing clay minerals for paleoclimatic reconstruction at dust sources and loess deposits. Therefore, this work explores clay mineral composition of modern dust source areas in southern South America and in the pampean loess records to gain insight into paleoenvironmental conditions prevailing during the late Pleistocene-early Holocene in the region. Clay minerals recovered from the loess deposits are of an allochthonous origin, implying their formation at the ‘arid diagonal’, then blown away, and deposited downwind in the Pampas without post-depositional changes. Clay mineral assemblages indicate that these minerals and rare earth elements (REE) analyzed in two loess sections of the Pampean Plain helped to reconstruct past climatic scenarios in the dust source areas during the transition from the last glacial to the current interglacial period. Furthermore, our work contributes to the assessment of the strengthening/weakening of the different South American dust sources in light of recent published geochemical and textural evidence.

Flood duration differentially affects seed germination, growth and ecophysiology of the swamp tree Citronella gongonha from the southern Neotropics

Citronella gongonha is an abundant tree species in flood-prone areas of southern South America. In swamp forests, young and adult individuals of the species are mainly distributed on hummocks. In this study, we address some aspects of the ecology and physiology of C. gongonha that contribute to the knowledge of its distribution in swamp forests. We evaluated seed germination and growth parameters, as well as chlorophyll, malondialdehyde, hydrogen peroxide, nitrate and carbohydrate levels in young C. gongonha plants during different periods of flooding. Germination did not occur under flooding conditions, and seeds persisted only up to 30 days of flooding, losing germination potential as submersion time increased. However, young plants survived a long period of flooding (until 120 days) by reducing growth, developing morphological adaptations and using carbohydrate pools. These results help to explain the distribution pattern of C. gongonha in swamp forests, predominantly on hummocks where soil flooding is attenuated.

Species boundary and extensive hybridization and introgression in Petunia

ABSTRACT Studying the role of hybridization in the speciation of plants is one of the most thrilling areas of evolutionary biology. Hybridization in natural populations can act in opposition to divergence, contribute to adaptation through introgression or foster the emergence of new lineages via hybrid speciation. Species of the plant genus Petunia grow in open areas in southern South America. Some natural interspecific hybrid events have been described for the genus, such as between the endemic P. exserta and the widespread P. axillaris. Both species occur in sympatry in Serra do Sudeste (Brazil), where they occur in diverse habitats and exhibit floral divergence, which has been related to the attraction of different primary pollinators. The present study evaluates the maintenance of the species boundaries front of hybridization and introgression. Direct and indirect methods of estimating gene exchange employed genotyping 720 reproductive plants and 611 progenies of both species with eight microsatellite loci. Gene exchange was found to be frequent and bidirectional between the species, indicating that introgression changes their genetic constitution in areas of sympatry. Limits of the studied species are being maintained because of the high level of inbreeding and backcrosses that are habitat-dependent.

First steps towards assessing the evolutionary history and phylogeography of a widely distributed Neotropical grassland bird (Motacillidae: Anthus correndera).

Grasslands in southern South America are extensive ecosystems which harbor a unique biodiversity; however, studies on the evolution of their taxa are scarce. Here we studied the phylogeography and population history of the Correndera Pipit (Anthus correndera), a grassland specialist bird with a large breeding distribution in southern South America, with the goals of investigating its phylogeographic history and relate it to the historical development of South American grasslands. The mitochondrial NADH dehydrogenase subunit II gene (ND2) was sequenced in 66 individuals from 19 localities and the intron 9 of the sex-linked gene for aconitase (ACOI9) was sequenced from a subset of those individuals, including all five subspecies of A. correndera, as well as the closely related A. antarcticus. Phylogenetic analysis revealed two distinct lineages within the complex: the first (A) corresponding to Andean subspecies A. c. calcaratus and A. c. catamarcae and the second (B) including birds traditionally assigned to A. c. correndera, A. c. chilensis, A. c. grayi and some individuals of A. c. catamarcae. A. antarcticus is nested within this second lineage. These results were also supported by evidence of niche divergence for variables associated with precipitation. The oldest split between clade A and B was estimated at c. 0.37 Mya, during the middle Pleistocene. Species distribution models for the present and the Last Glacial Maximum (LGM) suggest that grassland areas in southern South America remained relatively stable, in contrast to the general view of a reduction in grassland cover in South America since the LGM. Recent divergences and low phylogeographic structure (for lowland vs. highland geographic groups, intra-population genetic variance was greater than inter-groups; e.g., for ACOI9: 95.47% and ND2: 51.51% respectively), suggest widespread gene flow between lowland populations.

Pre-Hispanic earthwork engineering variability in the Upper Delta of the Paraná River. A comparative study between Los Tres Cerros mounds (Entre Ríos province, Argentina)

Earthworks are one of the most distinctive archaeological features in the wetland landscapes of South America. Herein, we provide a case study from one of the southernmost expressions of this earthworking phenomenon, the Paraná River Delta. In this flood-prone wetland, occupation strategies included the construction and habitation of earth-mounds and other topographically elevated areas in order to cope with deluges in a hydrometeorologically susceptible environment. We carried out planialtimetrical, sedimentary, bio-compositional and chronological analyses of the sedimentary matrix of two anthropogenical earthmounds, Los Tres Cerros site 1 and 2, and the results were compared in order to detect similarities and differences in the overall moundbuilding process. Besides its temporal and spatial closeness the succession of alternating humic and charcoal enriched lenses conforms surfaces were conditioning and maintenance activities were developed in both mounds, but the selection and sourcing of materials used in its construction presents notorious differences. Finally, we addresses the occupational strategies that guided the pre-Hispanic human settlement in lowland areas of southern South America and contribute to the acknowledgment of earthwork engineering variability in order to understand the evolution processes of the archaeological landscape of Los Tres Cerros archaeological locality.

Extremos na Concentração de Dióxido de Enxofre na Camada Limite Planetária no Sul da América do Sul - Comparação Entre Megacidades

In this study the value of the sulfur dioxide (SO 2 ) total column was assessed, to some of the major metropolitan areas of southern South America (Porto Alegre, Montevideo, Buenos Aires), using data from the sensor OMI (Ozone Monitoring Instrument) for the period 2005-2012. Their annual and monthly variations were investigated using the 99% percentile (P99) for the maximum daily values of the SO 2 total column in the planetary boundary layer (PBL). Among the regions analyzed, Montevideo had the highest value of P99 reaching 4,90 DU, being the region more contaminated by SO 2 of southern South America. The histograms indicate that the highest frequencies for the three regions analyzed are given in the first four classes of intervals. It was observed increasing values of trend line in the dispersion of the data for the three regions for the same period analyzed.

Acute Toxicity of Endosulfan to the Non-target Organisms Hyalella curvispina and Cnesterodon decemmaculatus.

Pesticide consumption in Argentina has steadily increased over the last two decades, while one of these compounds, namely endosulfan, is commonly found in environmental samples. Also the fish Cnesterodon decemmaculatus and the amphipod Hyalella curvispina are widely distributed in agricultural areas of southern South America. The aim of the present contribution was therefore to determine the acute toxicity of endosulfan to both organisms, and compare it with species sensitivity distributions (SSD) and measured field concentrations. The 48 h-LC50 (with 95 % confidence limits) were 1.8 (1.6-2.1) µg/L for C. decemmaculatus and 16.4 (15.1-17.7) µg/L for H. curvispina. C. decemmaculatus was more sensitive than 74 % of fish based on the SSD. Endosulfan concentrations in stream water reported in the literature were often higher than the C. decemmaculatus LC50. It may hence be concluded that C. decemmaculatus is a suitable sentinel organism for ecotoxicological risk assessment in South America.

Diversity and paleoenviromental significance of Brazilian fossil Galictis (Carnivora: Mustelidae)

The evolutionary history of the genus Galictis in South America probably begins after the Great American Biotic Interchange. Two species are recognised: Galictis vittata and Galictis cuja. The latter are more frequently found in open areas in southern South America and the first occurs in humid forests from northern South America to Central America. Apparently, they do not occur in sympatry. Both are differentiate by the presence of a metaconid in the first inferior molar of G. vittata and for its bigger size when compared to G. cuja. The fossil record of Galictis is scarce, G. cuja is known by few specimens from Argentina, Chile and Brazil; G. vittata have only one record from Southern Brazil. The specimens related to this record were collected by Peter Lund and are housed at the Statens Naturhistoriske Museum. However, the specimens published by Lund are not fossils. Thus, it is presented here other unpublished specimens collected by Lund and housed at the same museum that we recognise as the first G. vittata fossils. Additionally, it is described here the first fossil record for G. cuja from the late Pleistocene of Brazil – an almost complete mandible recovered from sedimentary deposits from Central Brazil.

A new enigmatic Late Miocene mylodontoid sloth from northern South America.

A new genus and species of sloth (Eionaletherium tanycnemius gen. et sp. nov.) recently collected from the Late Miocene Urumaco Formation, Venezuela (northern South America) is herein described based on a partial skeleton including associated femora and tibiae. In order to make a preliminary analysis of the phylogenetic affinities of this new sloth we performed a discriminate analysis based on several characters of the femur and tibia of selected Mylodontoidea and Megatherioidea sloths. The consensus tree produced indicates that the new sloth, E. tanycnemius, is a member of the Mylodontoidea. Surprisingly, the new taxon shows some enigmatic features among Neogene mylodontoid sloths, e.g. femur with a robust lesser trochanter that projects medially and the straight distinctly elongated tibia. The discovery of E. tanycnemius increases the diversity of sloths present in the Urumaco sequence to ten taxa. This taxon supports previous studies of the sloth assemblage from the Urumaco sequence as it further indicates that there are several sloth lineages present that are unknown from the better sampled areas of southern South America.

Several origins of floral oil in the Angelonieae, a southern hemisphere disjunct clade of Plantaginaceae.

• Over the past 75 Myr, successive groups of plants have entered the "oil bee pollination niche," meaning that they depend on oil-collecting bees for their pollination. The highly dissimilar numbers of plant species and bee species involved in these mutualisms imply evolutionary host switching, asymmetric mutual dependencies, and uncoupled diversification. Among the clades with the best field data on oil bee behavior is the Angelonieae, which we here investigate to better understand the evolutionary time frame of this pollination syndrome.• We generated nuclear and plastid data matrices for 56% of the Angelonieae species (plus outgroups) and used Bayesian methods of molecular clock dating, ancestral state reconstruction, and biogeographic inference.• We found that Angelonieae have two major clades, Angelonia (including Monopera) and Basistemon, and Monttea, Melosperma, and Ourisia.• Angelonieae date back to the Uppermost Eocene, ca. 35 (26-47) Myr ago (Ma) and diversified in dry areas of southern South America; they switched from nectar to oil as a reward four or five times over the past 25 Ma. As predicted in a previous non-clock-dated study, dispersal to Australasia dates to the Miocene/Pliocene.

Holocene glacier history of the Lago Argentino basin, Southern Patagonian Icefield

We present new geomorphic, stratigraphic, and chronologic data for Holocene glacier fluctuations in the Lago Argentino basin on the eastern side of the southern Patagonian Andes. Chronologic control is based on 14C and surface-exposure 10Be dating. After the Lateglacial maximum at 13,000 cal yrs BP, the large ice lobes that filled the eastern reaches of Lago Argentino retreated and separated into individual outlet glaciers; this recession was interrupted only by a stillstand or minor readvance at 12,200 cal yrs BP. The eight largest of these individual outlet glaciers are, from north to south: Upsala, Agassiz, Onelli, Spegazzini, Mayo, Ameghino, Perito Moreno, and Grande (formerly Frías). Holocene recession of Upsala Glacier exposed Brazo Cristina more than 10,115 ± 100 cal yrs BP, and reached inboard of the Holocene moraines in Agassiz Este Valley by 9205 ± 85 cal yrs BP; ice remained in an inboard position until 7730 ± 50 cal yrs BP. Several subsequent glacier readvances are well documented for the Upsala and Frías glaciers. The Upsala Glacier readvanced at least seven times, the first being a relatively minor expansion – documented only in stratigraphic sections – between 7730 ± 50 and 7210 ± 45 cal yrs BP. The most extensive Holocene advances of Upsala Glacier resulted in the deposition of the Pearson 1 moraines and related landforms, which are divided into three systems. The Pearson 1a advance occurred about 6000–5000 cal yrs BP and was followed by the slightly less-extensive Pearson 1b and 1c advances dated to 2500–2000 and 1500–1100 cal yrs BP, respectively. Subsequent advances of Upsala Glacier resulted in deposition of the Pearson 2 moraines and corresponding landforms, also separated into three systems, Pearson 2a, 2b, and 2c, constructed respectively at ∼700, >400, and <300 cal yrs BP to the early 20th century. Similar advances are also recorded by moraine systems in front of Grande Glacier and herein separated into the Frías 1 and Frías 2a, 2b, and 2c. The Onelli and Ameghino glacier valleys also preserve older Holocene moraines. In the Agassiz, Spegazzini, and Mayo valleys, ice of the late-Holocene advances appears to have overridden landforms equivalent in age to Pearson 1. Perito Moreno Glacier is an extreme case in which ice of historical (Pearson 2c) advances overrode all older Holocene moraines. Based on the distribution and number of moraines preserved, we infer that the response to climate differed among the Lago Argentino outlet glaciers during the Holocene. This led us to examine the effects of climatic and non-climatic factors on individual glaciers. As a consequence, we detected an important effect of the valley geometry (hypsometry) on the timing and magnitude of glacier response to climate change. These results indicate that caution is needed in correlating moraines among glacier forefields without firm morpho-stratigraphic and age control. Finally, we note important similarities and differences between the overall moraine chronology in the Lago Argentino basin and that in other areas of southern South America and elsewhere in the Southern Hemisphere.

Distribution and traits of climbing plants in subtropical and temperate South America

AbstractQuestionsHow do climbing species richness and composition change between subtropical and temperate areas of southern South America? How do growth form (lianas and vines) and climbing mechanisms change between subtropical and temperate areas of southern South America? How much of the diversity of species and traits of the extratropical climbing flora is derived from taxa shared with the tropical region?LocationSubtropical (23–30° S) and temperate (&gt;30° S) areas of South America.MethodsAn extensive literature search was carried out in the main databases concerning the flora of southern South America. Climbing species occurrence in subtropical and temperate areas and climbing traits were retrieved. Differences in the frequencies of both growth forms and climbing mechanisms between areas were evaluated using chi‐square analyses. Trait frequencies in subtropical and temperate floras were analysed with and without considering species shared with the tropical region.ResultsClimbing species richness decreased from subtropical to temperate areas, and there were changes in the taxonomic composition. The frequency of growth forms and climbing mechanisms differed between subtropical and temperate areas. Herbaceous vines accounted for 85% of temperate‐exclusive species. Twiners contributed less to climber richness in the temperate area, while tendril‐bearers and leaf‐climbers became more important; root‐climbers were only found in temperate forests. Species shared with the tropical region increase the number of liana species in both subtropical and temperate floras, but alter the frequencies of climbing mechanisms in the subtropical flora only.ConclusionsResults call for a re‐evaluation of the importance that is given to climbers in regions outside the tropics. Vines must be included in models of distribution and abundance of climbers in order to gain a better understanding of climbing plant ecology. The association between climbing mechanisms and the success of climbing plant species in different ecosystems must be further investigated.

Susceptibility of Argentinean Biomphalaria tenagophila and Biomphalaria straminea to infection by Schistosoma mansoni and the possibility of geographic expansion of mansoni schistosomiasis

Human migration and the presence of natural vectors (mollusks) of Schistosoma mansoni are the primary causes of the expansion of mansoni schistosomiasis into southern areas of South America. Water conditions are favorable for the expansion of this disease because of the extensive hydrographic network, which includes the basins of the Paraná and Uruguay rivers and favors mollusk reproduction. These rivers also aid agriculture and tourism in the area. Despite these favorable conditions, natural infection by S. mansoni has not yet been reported in Argentina, Uruguay, or Paraguay. Two species of planorbid from Argentina, Biomphalaria straminea and B. tenagophila, were exposed to the miracidia of five Brazilian strains of S. mansoni. Biomphalaria tenagophila (Atalaya, Buenos Aires province) was infected with the SJS strain (infection rate 3.3%), confirming the experimental susceptibility of this Argentinian species. Biomphalaria straminea (Rio Santa Lucía, Corrientes province) was susceptible to two Brazilian strains: SJS (infection rate 6.7%) and Sergipe (infection rate 6.7%). These results demonstrate that species from Argentina have the potential to be natural hosts of S. mansoni and that the appearance of foci of mansoni schistosomiasis in Argentina is possible.

Climate anomalies and epidemics in South America at the end of the Colonial Period

Climate is one of the most of influential natural factors on society and economy. One of the consequences of climate anomalies is the emergence of diseases and epidemics, especially in agrarian societies. The current concern with long-term climate change and its measurable consequences on health and disease gives new relevance to the question of how agrarian societies fared during sharp droughts and other climatic hardships, especially those subject to the disruptive processes of colonization. Not many studies have been done in Latin America that relate climate, epidemics and mortality from a historical perspective. This paper explores the association between climatic anomalies, epidemic events, and native demographic decline in the Alto Peru region in the highlands of Bolivia, in the late eighteenth and early nineteenth century. Studies of historic climatology indicate that adverse climate events became more frequent in the southern areas of South America during these centuries. There were extreme oscillations in precipitation, especially beginning in the 1750’s which significantly impacted the largest group of people in late colonial Alto Peru: the indigenous population, whose vulnerability increased in face of local climatic anomalies and the resulting epidemiological risk. Both the quantitative and the qualitative analysis show associations between climatic and epidemic events.

Study of the Hepatoprotective Activity of Methanolic Extract of Feijoa sellowiana Fruits Against MDMA using the Isolated Rat Liver Perfusion System.

liver injury induced by viruses, chemicals and drugs can be protected by different medicinal plants. Feijoa sellowiana (Myrtaceae) is an evergreen bush native to southern areas of South America, as well as Iran where the fruits are very popular. Feijoa has shown a potent antimicrobial effect. Morever, the antioxidant activity of total Feijoa extract has also been reported. MDMA or ecstasy is a ring-substituted amphetamine derivative which has been abused as a widespread recreational drug by the young generation. Liver is a target organ for MDMA toxicity. In fact, this sense MDMA is metabolized by cytochromes P4502D, 2B and 3Aand reactive metabolites are readily oxidized to the corresponding o-qiuinones and reactive oxygen species (ROS). This study investigated whether methanilic Feijoa sellowiana fruits can produce biochemical changes using the Isolated Rat Liver Perfusion (IRLP) system. The, the liver was perfused with different concentrations of the extract (10, 20, 40, 50,100 mg/kg), added to the buffer and perfused within 2 h. During the perfusion we tried to find out the antioxidant activity or liver protective effect of Feijoa, by determinining amino-transferases activities (SGOT and SGPT ) and glutathione reductase (GSH) level in comparison with the positive and negative controls. Subsequently, sections of liver tissue were examined for any histopathological changes. The results revealed that the activities of SGOT and SGPT were seriously decreased and GSH level was significantly increased by the Feijoa extract. Overall, necrosis in the liver parenchyma was decreased. These findings revealed that Feijoa sellowiana is an effective hepatoprotective plant.

&lt;p class="HeadingRunIn"&gt;&lt;strong&gt;Transfer of &lt;em&gt;Geoblasta pennicillata&lt;/em&gt; to &lt;em&gt;Bipinnula&lt;/em&gt; (Chloraeinae, Orchidaceae)&lt;/strong&gt;&lt;/p&gt;

The genus Bipinnula Comm. ex Jussieu (1789: 65) includes 11–12 species distributed in two disjunct areas of southern South America. One of these comprises southern Brazil, Uruguay, and eastern Argentina, where six species occur, and the other is Chile where the rest of the species are found (Gosewijn 1993, Pridgeon et al. 2003, Cisternas et al. 2012). Szlachetko & Margonska (2001), based on intuitive assessments of floral characters, speculated that Bipinnula ‘is polyphyletic and consists of two apparently unrelated groups, Bipinnula and Jouyella Szlachetko & Margonska (2001: 124). However, Jouyella is identical in circumscription to Bipinnula section Multiflorae Gosewijn (1993: 15) and we do not see the advantage of inflating nomenclature with further genera for which monophyly has not been formally tested. Therefore, we consider Jouyella as a synonym of Bipinnula .

The phylogenetic relationships of four monospecific caesalpinioids (Leguminosae) endemic to southern South America

AbstractBalsamocarpon,Lophocarpinia, Stenodrepanum and Zuccagnia are monospecific endemic genera from arid or saline areas of southern South America (Argentina, Paraguay, Chile). Several molecular studies have explored relationships within Caesalpinioideae and the Caesalpinia group but, until now, Stenodrepanum has not been included, Lophocarpinia has been poorly represented and these four South American taxa have not been analyzed together. In order to resolve their evolutionary relationships, a phylogenetic analysis of the plastid trnL–F intron and spacer region that included a broad range of published sequences from Caesalpinieae was used. Combined trnL–F, matK/trnK and morphological data were analysed for a subset of taxa. Stenodrepanum, Balsamocarpon and Zuccagnia formed a monophyletic group with the amphitropical American genus Hoffmannseggia. The clade shares a synapomorphy of sepal persistence in the fruit. Lophocarpinia is shown also to belong to the Caesalpinia informal generic group as traditionally proposed, and grouped with Haematoxylum with which it shares the presence of branches and inflorescences crowded on short shoots and spines derived from branches. As a contribution to the understanding of the Caesalpinia group, phylogenetic hypotheses were used to discuss evolution of selected characters within the group.