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Importance of nurse plants structuring plant communities is well‐appreciated at local scales, yet the effect of a single nurse on large scales has been neglected in analyses. So far, studies only use environmental gradients within one type of ecosystem and tend to generalize the nurse effects.To assess how the effect of a single nurse species is modulated by different environmental settings, interactions between the shrub Vachellia caven and the surrounding plant communities were evaluated at 481 paired plots (outside vs. underneath the plant crown), in 39 sites across two distribution ranges, the Mediterranean west and the mostly subtropical east of the Andes Mountains (covering ca. 2 × 106 km2).Cover, abundance and richness of perennial plants underneath and outside V. caven were used as response variables to estimate an index indicative of plant interactions (relative interaction index [RII]) and tested how this was affected by the rainfall gradient and distribution range.Overall, RII responses to rainfall gradients had low conditional R2 (~0.25) in this large scale of analysis, but were significantly different between ranges: the RII followed a quadratic trend across the rainfall gradient in the western range, while this relationship was positive and close to linear at the eastern range.Then, by projecting the RII models (i.e. for abundance, cover and richness) spatially through a consensus map, we show that most positive effects of V. caven are geographically found in dissimilar areas: the central part of Chile (western range) and across the Paraná River (eastern range).When local fine‐scale predictors (i.e. annual herbs' cover and height, and herbivores' faeces cover) were used to model each response variable at the plot level (underneath or outside V. caven), we observed similar trends as when we considered only the large‐scale predictors.Synthesis. Here, we show that the effect of the same nurse species on neighbouring plant communities can be very different depending on ranges of distribution, stressing that its ecological function cannot be generalized and not only depends on local factors but also is large‐scale context‐dependent. [ABSTRACT FROM AUTHOR]

Copyright of Lilloa is the property of Fundacion Miguel Lillo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The lygaeoid Orsillus depressus Dallas feeds on seeds of several species, mainly cypress. Since the end of the last century, it has extended its range from its native area in the Mediterranean Basin towards northeastern Europe and it is considered an invasive species. In the present work, the presence of O. depressus is reported for the first time from the New World and Southern Hemisphere. Host plants and distribution from central-southern Argentina are given. In addition, morphological characters that allow their identification are provided. [ABSTRACT FROM AUTHOR]

The ArgVeg is a repository of vegetation-plots data registered in the Global Index of Vegetation Databases (GIVD ID: SA-AR-002). This report presents its main characteristics, potential uses, and future perspectives. In September 2022, the database contained 1092 vegetation-plot records, including 1184 valid native and non-native vascular plants. The database covers the main vegetation types of nine vegetation units of the Chaco, Espinal and Pampean phytogeographic provinces in central Argentina. Those types include native forests, shrublands, grasslands, halophytic vegetation and non-native woody communities present in either lowlands or mountain areas. This database represents a significant improvement in the availability of floristic information from subtropical and warm temperate areas in South America, which still represents a major knowledge gap worldwide. ArgVeg reflects the outstanding plant diversity of central Argentina and it is managed by the Plant Ecology and Phytogeography Group at the Multidisciplinary Institute of Plant Biology (Córdoba, Argentina). Not only the high biodiversity but also the complex landscape heterogeneity are the most important characteristics of the vegetation in this region. We hope to increase the number of plots in the near future and to strengthen regional and global networks to enhance the conservation and management of these endangered ecosystems. [ABSTRACT FROM AUTHOR]

Background and Aims Cunoniaceae are woody plants with a distribution that suggests a complex history of Gondwanan vicariance, long-distance dispersal, diversification and extinction. Only four out of ~27 genera in Cunoniaceae are native to South America today, but the discovery of extinct species from Argentine Patagonia is providing new information about the history of this family in South America. Methods We describe fossil flowers collected from early Danian (early Palaeocene, ~64 Mya) deposits of the Salamanca Formation. We compare them with similar flowers from extant and extinct species using published literature and herbarium specimens. We used simultaneous analysis of morphology and available chloroplast DNA sequences (trnL – F , rbcL , matK , trnH – psbA) to determine the probable relationship of these fossils to living Cunoniaceae and the co-occurring fossil species Lacinipetalum spectabilum. Key Results Cunoniantha bicarpellata gen. et sp. nov. is the second species of Cunoniaceae to be recognized among the flowers preserved in the Salamanca Formation. Cunoniantha flowers are pentamerous and complete, the anthers contain in situ pollen, and the gynoecium is bicarpellate and syncarpous with two free styles. Phylogenetic analysis indicates that Cunoniantha belongs to crown-group Cunoniaceae among the core Cunoniaceae clade, although it does not have obvious affinity with any tribe. Lacinipetalum spectabilum , also from the Salamanca Formation, belongs to the Cunoniaceae crown group as well, but close to tribe Schizomerieae. Conclusions Our findings highlight the importance of West Gondwana in the evolution of Cunoniaceae during the early Palaeogene. The co-occurrence of C. bicarpellata and L. spectabilum , belonging to different clades within Cunoniaceae, indicates that the diversification of crown-group Cunoniaceae was under way by 64 Mya. [ABSTRACT FROM AUTHOR]

Understanding how abiotic factors influence organisms at present is the necessary first step to predict how species assemblages could be affected by climate change in the future. We examined how wind, a poorly studied abiotic factor, affects the distribution and abundance of two aphid species, Uroleucon aeneum and Brachycaudus cardui (hereafter black and green aphids, respectively), that live on the thistle Carduus thoermeri (Asteraceae) in a windy region of Patagonia, Argentina. First, considering the prevailing wind direction, we described the distribution of both aphid species around plant stems. Then, we performed a bi‐factorial experiment in which we cut stems with aphids to manipulate their position respect to wind (exposed/unexposed) and to control wind incidence (protected/unprotected). Finally, using the species most affected by wind, we examined possible mechanisms through which wind could affect aphids. Both aphid species were less abundant on the side of the stem exposed to wind respect to the unexposed side; and this pattern was stronger for the black aphid. When black aphids were positioned exposed to wind and without protection, their proportion changed towards the unexposed side of the stem; while green aphids showed a weaker response to wind. Laboratory experiments demonstrated that wind triggered both the detachment of black aphids and their movement towards the unexposed side of the stem. Our results showed that wind can explain the asymmetric distribution of aphids around plants and that stems can act as windbreaks. In a less windy future scenario, aphids could expand their foraging area, reaching higher infestation rates, which could affect their role in structuring ant assemblages and their status as crop pests. This work highlights the importance of testing the effects of less studied abiotic factors to fully understand how climate change could impact on the abundance and distribution of animals in the future. [ABSTRACT FROM AUTHOR]

Background and aims: The geographical distribution of Tillandsia recurvata ranges from the southern United States to the center of the Argentine. The aim of this work is to report the presence of this species 200 km south of its known distribution and to discuss the causes that may have led to this range expansion. M & M: Specimens were collected in different locations in the province of Buenos Aires. Herbaria collections, on-line databases and bibliography were analyzed to corroborate the taxonomic identification and the distribution limit of the species. Results: We present novel records of Tillandsia recurvata that extend its geographic distribution 200 km towards the South, being the locality of Tandil the southernmost site of occurrence. Conclusions: Because the dates of collection and observations are recent, we consider that this advance occurred in the last decades. Possible causes are discussed, such as climate change and lignification of the Pampas. [ABSTRACT FROM AUTHOR]

Salvia is the biggest genus from Lamiceae, with almost 900 species. In Argentina it is represented by 23 taxa (20 species, one subspecies, and two varieties), four of these are adventive taxa, the rest are native, and one of these is endemic. Species are distributed predominantly in the north region of the territory, reaching the provinces of La Pampa and Mendoza as the southern limit of its distribution. Each of the 23 Salvia taxa present in Argentina is described and illustrated, and a key for their identification is presented. Three new synonyms are proposed, Salvia borjensis new synonym of Salvia nervosa, Salvia durifolia new synonym of Salvia ovalifolia var. ovalifolia and Salvia alba new synonym of Salvia personata, and ten lectotypes are designated for: Salvia approximata, S. arenaria, S. ovalifolia var. villosa, S. pallida, S. procurrens, S. reflexa, S. serrata, S. stachydifolia, S. uliginosa, and Salvia sect. Pycnosphace. [ABSTRACT FROM AUTHOR]

Azorella is a genus with 26 species of Azorelloideae (Apiaceae) that grow from Costa Rica to the subantartic islands, being distintive and dominant in different environments of the Andean Cordilleras from Venezuela to Patagonia. The species of Azorella that grow in Argentina have been revised taxonomically in a previous study. However, knowledge of the remaining species is fragmentary and uneven. The aim of this paper is to update and standardize the information of the 11 species of Azorella absent in Argentina and present in Bolivia, Chile, Colombia, Ecuador, Peru and/or Venezuela. We provide descriptions for those species and update distributional maps, and we solve nomenclatural and typification problems for 41 names, designating 2 type species, 16 lectotypes and 1 neotype. In addition, we provide 10 new illustrations, and an identification key for all the species of the genus. [ABSTRACT FROM AUTHOR]

We compiled a checklist with all known endemic plants occurring in the Sierras of Córdoba and San Luis, an isolated mountainous range located in central Argentina. In order to obtain a better understanding of the evolutionary history, relationships and age of the regional fora, we gathered basic information on the biogeographical and foristic afnities of the endemics, and documented the inclusion of each taxon in molecular phylogenies. We listed 89 taxa (including 69 species and 20 infraspecifc taxa) belonging to 53 genera and 29 families. Te endemics are not distributed evenly, being more abundant in the lower than in the middle and upper vegetation belts. Tirty-two genera (60.3%) have been included in phylogenetic analyses, but only ten (18.8%) included local endemic taxa. A total of 28 endemic taxa of the Sierras CSL have a clear relationship with a widespread species of the same genus, or with one found close to the area. Available phylogenies for some taxa show divergence times between 7.0 - 1.8 Ma; all endemic taxa are most probably neoendemics sensu Stebbins and Major. Our analysis was specifcally aimed at a particular geographic area, but the approach of analyzing phylogenetic patterns together with foristic or biogeo- graphical relationships of the endemic taxa of an area, delimited by clear geomorphological features, could reveal evolutionary trends shaping the area. [ABSTRACT FROM AUTHOR]

Anadenanthera colubrina var. cebil is a discontinuously distributed native tree species in South American subtropical forests. Thirteen quantitative traits and eight nuclear microsatellite loci were examined in individuals from two biogeographic provinces of Argentina to determine the number and composition of genetically distinguishable groups of individuals and explore possible spatial patterns of the phenotypic and genetic variability. Means of reproductive traits were higher in the Yungas than in the Paranaense biogeographic province, whereas five out of eight nonreproductive quantitative traits showed higher mean values in the latter. Variance coefficients were moderate, and there were significant differences between and within provinces. Three clusters were defined based on spatial model for cluster membership for quantitative traits. One cluster grouped the individuals from the Paranaense biogeographic province whereas the individuals from the Yungas biogeographic province grouped regarding its population of origin. Parameters of molecular genetic variability showed higher values in the Yungas than in the Paranaense biogeographic province. Observed heterozygosity was lower than expected heterozygosity in both biogeographic provinces, indicating an excess of homozygosity. The homozygosity test by Watterson and the exact test by Slatkin suggested diversifying selection for locus Ac41.1. Bayesian clustering spatial model for microsatellites loci data were performed for both all loci and for all loci excluding locus Ac41.1. In both analyses two clusters were inferred. Analysis of molecular variance revealed similar results for all genotypes and for all genotypes defined excluding locus Ac41.1. Most of the total variance is attributable to genetic variation within clusters. The presence of homogeneous clusters was detected for both the phenotypic and molecular genetic variability. Two Bayesian clustering analyses were performed according to molecular genetic data, and two clusters were inferred. Individuals were assigned to their provinces of origin. Genetic molecular variation was higher in the populations of the Yungas biogeographic province which translates into highly qualified populations for conservation. Populations from the Paranaense biogeographic province showed the highest mean value of number of seeds per fruit making them valuable as well with regard to the exploitation of management strategies as a means to recover the impacted areas where these populations are located. [ABSTRACT FROM AUTHOR]

Copyright of SHILAP Revista de Lepidopterologia is the property of Sociedad Hispano-Luso-Americana de Lepidopterologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Brachistosternus Pocock 1893 is the most diverse genus of the scorpion family Bothriuridae. Only four species of the genus have been cytogenetically analyzed so far. We report herein the cytogenetic analysis of Brachistosternus alienus Lönnberg 1898 from Comallo (Río Negro province, Argentina). This species is widely distributed in the Monte phytogeographic province, located in central and northern Argentine Patagonia. Meiotic cells of B. alienus from Comallo show 23 homomorphic achiasmatic bivalents. The karyotype of this species contains scarce AT-rich regions that may be associated with the heterochromatin of centromeric regions. Giacomozzi (1977) reports n = 14 for B. alienus from Chubut province. Unfortunately, it is not presently possible to determine if those specimens correspond to B. alienus or to a sympatric species, Brachistosternus angustimanus Ojanguren-Affilastro & Roig-Alsina 2001. These different chromosome numbers of the two populations analyzed may reflect the occurrence of a chromosomal polytypism in B. alienus, or they may characterize different species. [ABSTRACT FROM AUTHOR]

A new generic and specific record for the Argentinean Flora, Allamanda schottii Pohl (Apocynaceae), is documented. The species was found on the banks of the Paraná River, in north of Corrientes, Argentina. Synonymy, description, distribution, habitat, phenology, reproductive biology, common names, uses and observations are included. [ABSTRACT FROM AUTHOR]

The aim of this work was to study the pollen profile of clover and eucalyptus honeys from the Phytogeographic Pampean Province of Argentina, in order to contribute to its palynological characterization. Qualitative pollen analysis was performed. Descriptive and multivariate statistical techniques were applied to determine the frequency distribution of pollen and characterize each floral origin by pollen and year of harvest. 81 samples of honey from four different harvests were analyzed. 41 morphological types of pollen were found, which variation per sample ranged from two to eight. Eucalyptus sp. was the taxon present in over 80% of the honeys. There were pollen of Helianthus annuus and Carduus sp. in clover and eucalyptus honeys but pollen of Brassicaceae was only present in clover honeys. Pollen spectra showed differences between the studied years. [ABSTRACT FROM AUTHOR]

Abstract: Fluvial hydrosystems are environments with large landscape to water surface ratio and therefore particularly vulnerable to changes in land use. We analysed the connection of environmental conditions in 31 prairie streams of the Pampa Plain (Argentina) with regional phytogeography and surrounding land use. Furthermore, the relationships between riparian conditions, macrophytes and water physico-chemistry on the reach scale were explored by considering nutrient levels, pH, water conductivity, riparian conditions and the presence of in-stream vegetation cover. Streams draining croplands were characterized by better conservation of the riparian zone, lower pH and higher nitrate than those exposed to cattle intrusion. Unlike surrounding land use, our results revealed that regional phytogeography showed only marginal significant effects on streams. Our results also revealed that a particular combination of environmental variables (poor riparian conditions, high total phosphorous, high pH and low nitrate) was detrimental for the presence of macrophytes. However, the abundance of submersed and emergent macrophytes was not dependent on surrounding land use nor on regional phytogeography. [Copyright &y& Elsevier]

A review of the Lycopodiaceae from Argentina and Uruguay, based on the study of relevant collections from herbaria as well as literature, is presented, according to the new classification of 16 genera grouped into three subfamilies. The family is represented by nine genera and 23 species; all taxa are described and at least one species of each subfamily is illustrated; one species (Huperzia saururoides) is lectotypified and three new synonyms are proposed: Austrolycopodium assurgens under Austrolycopodium erectum, Lycopodium sanctae-barbarae under Phlegmariurus saururus and Urostachys selago var. aschersonianus under Huperzia saururoides. Lycopodiella alopecuroides and Phlegmariurus subulatus are excluded from the studied area. Keys for all taxa are provided, as well as the relevant synonyms and a synthesis of the ecology and distribution. The most diverse genera are Phlegmariurus (seven species) and Austrolycopodium (five species). In Argentina, the family is represented by 22 species distributed in the three subfamilies. The northwestern region is the richest area of the country, with nine species. In Uruguay the family is represented by the subfamily Lycopodielloideae, with four species belonging to the genera Lycopodiella (two species), Palhinhaea (one species) and Pseudolycopodiella, represented by Pseudolycopodiella meridionalis. The latter, Palhinhaea camporum, and Huperzia fuegiana s. str. are new records for Argentina. [ABSTRACT FROM AUTHOR]

The morphological variation in vegetative and reproductive structures of Bauhinia mollis (var. mollis and var. notophila) and B. argentinensis (var. argentinensis and var. megasiphon) were studied. This detailed morphological study enabled us to correctly identify herbarium specimens and expand the geographic distribution of the taxa. New records of B. mollis var. mollis for Argentina and B. argentinensis var. argentinensis and B. argentinensis var. megasiphon for Bolivia, the latter considered endemic to Argentina, are here confirmed. Lectotypes were designated for Bauhinia mollis, B. mollis var guaranitica and B. appendiculata. [ABSTRACT FROM AUTHOR]

This paper includes four ornamental species of the genus Bryophyllum (Crassulaceae): B. daigremontianum (Raym.-Hamet & H.Perrier) A.Berger, B. delagoense (Eckl. & Zeyh.) Schinz, B. fedtschenkoi(Raym.-Hamet& H.Perrier) Lauz.-March. and B. pinnatum (Lam.) Oken, all naturalized in Argentina. The first three are new records for this country; for B. pinnatum, cited previously, its area is extended. Also includes an identification key, descriptions, distribution, ethnobotanical data, reference material and comments on their naturalization. [ABSTRACT FROM AUTHOR]

Cyrtopodium paniculatum (Ruiz & Pav.) Garay is described for the first time for the Argentine flora. Synonyms, some ecological observations and the key to distinguish it from related species are included. Besides, the identity of other species previously recognized for Argentina, C. pflanzii, is clarified. [ABSTRACT FROM AUTHOR]

Tillandsia myosura (Bromeliaceae), new report for the Province of Buenos Aires, Argentina. Collected near Pereyra River, Provincial Park and Biosphere Reserve Parque Pereyra Iraola (Berazategui, Buenos Aires, Argentina). This species, known so far only for southern Uruguay and Catamarca, Cordoba, Jujuy, La Rioja, La Pampa, Mendoza, Salta, San Juan, San Luis, Santiago del Estero and Tucuman in Argentina, is cited for the first time the Province of Buenos Aires, expanding its southern limit of distribution in the country. A description and illustration along with a key to differentiate it from related species is given. [ABSTRACT FROM AUTHOR]

After the most recent phylogenetic analyses of Gavilea, an updated taxonomic revision is presented here. A new combination, Gavilea chica, is proposed following the current monophyletic circums- cription of the genus. This revision includes: 1) the history of the genus, 2) a key to the 17 species of Gavilea, 3) descriptions and illustrations of most species, 4) updated geographical distribution of the species, including the extension of the range of distribution of G. platyantha and G. supralabellata to Río Negro and Tierra del Fuego (Argentina) respectively, 5) nomenclatural observations and, 6) a complete and updated list of synonyms for every species. Five lectotypes (Asarca araucana, G. australis, A. patagonica, G. supralabellata, and G. wittei) are also designated. [ABSTRACT FROM AUTHOR]

Guadua tagoara subsp. tagoara is reported for the first time in Argentina, it is described and illustrated. A map showing its geographical distribution in South America and a key to the species and subspecies in Argentina are also provided. A lectotype for Bambusa distorta is here designated. [ABSTRACT FROM AUTHOR]

We describe a new species of Phymaturus from the Sierra La Invernada of San Juan Province, Argentina. The new species shares the apomorphies of the P. palluma group including a fragmented subocular, square nonimbricate supercillarles, rugose and strongly mucronate dorsal caudals, and a midvertebral band of enlarged scales. Within the P. palluma group, the new species can be assigned to the Puna clade, with which it shares a dorsal pattern of small, dispersed brown spots and lack of black reticulations. The new species differs from other members of the Puna clade in several aspects of squamation and body pattern and color. Most notably, the new Phymaturus has a conspicuous yellow scapular spot, lacks a vertebral stripe, and has incomplete dark pigmentation over the dorsal neck. The new species is known only from the region of the type locality, the southernmost (and geographically isolated) extent of the Puna phytogeographic province, where it occurs at high elevations (>3100 m). We provide information on aspects of the natural history, diet, thermal biology, and apparent parental care exhibited by females of the new species. [ABSTRACT FROM AUTHOR]

Miconia petropolitana is reported for the first time for the Argentinean flora and a lectotipification for this species is proposed. The species is described and illustrated and a map with the geographical distribution is provided. Miconia elegans is excluded from Argentina and an identification key for the species is included. [ABSTRACT FROM AUTHOR]

The species in the Sporobolus indicus complex are analyzed for Argentina. Sporobolus indicus var. indicus and S. indicus var. andinus are recognized for Argentina based on significant value differences in culms height and inflorescence length, and the altitude of collection area. The var. andinus is a new record for the Argentinean flora and it is here illustrated. Sporobolus jacquemontii is excluded from Argentina and S. minor is considered as a synonymy of S. indicus var. indicus. [ABSTRACT FROM AUTHOR]

A new record for the Argentinean flora, Samanea tubulosa, is described and illustrated. The specimens were collected in Oran, Salta Province, Argentina, in the "Selvas Pedemontanas" district of the "Yungas" phytogeographic province. Comments on the systematic position of the species and related genera are given. [ABSTRACT FROM AUTHOR]

This paper includes nine adventitious species of Prunus (Rosaceae, Prunoideae) present in Argentina. A key is presented to differentiate them. For all the species, it is indicated scientific name, common names, description, geographical distribution, uses, material studied and observations about their status of naturalization. [ABSTRACT FROM AUTHOR]

This paper includes the first record of Carya illinoinensis (Wangenh.) K. Koch for Argentina, and considerations about its status in the context of the naturalization process. Also includes observations about exotic species of Juglans in this country. [ABSTRACT FROM AUTHOR]

Six new species of Malvastrum are described: M. boyuibeanum, M. Cristobalianum, M. ionthacarpum, M. pucariensis, M. trifidum and M. uniapiculatum and a new combination is proposed: M. Fryxellii. [ABSTRACT FROM AUTHOR]

Oncidium fuchsii Königer (Orchidaceae) is described for the first time for the Argentinean flora. Synonyms, some ecological observations and a key to differentiate the entity with which can made a mistake, are included. [ABSTRACT FROM AUTHOR]

Roadsides may homogenize the distribution of native species and act as corridors for the spread of alien taxa. We examined the variation in native and alien plant species richness and composition at two spatial scales defined by altitude and habitat type (edges and fill slopes), as well as the relationship between native and exotic species richness in roadside plant communities in mountains from central Argentina. Following a gradient from 1100 to 2200 m a.s.l. along a mountain road, plant species cover was recorded within sample plots of 30 m × 10 m systematically located at 100-m altitude intervals on both roadside habitats. Although native species richness decreased with altitude and composition changed accordingly, the number of alien species peaked at both extremes of the elevation gradient and did not reflect an altitudinal replacement of chorological groups. The number of both native and alien species was higher in roadside edges, but a negative association between the richness of native and alien species occurred only on fill slopes, suggesting that roadside habitats differ in their susceptibility to plant species colonization and in the mechanisms driving native and alien species richness. Our results highlight the importance of altitude and roadside habitat as factors controlling plant species richness and composition along roadside communities in central Argentina. Although altitude acts as a filter for native plants, it apparently did not constrain the establishment of alien species along the studied roadsides, indicating that the influence of this road as a plant species corridor may increase with time, promoting the opportunities for aliens to expand their current distribution. [ABSTRACT FROM AUTHOR]

Peperomia nitida and P. armondii (Piperaceae, subgen. Rhyncophorum) are recorded for the first time for the Argentinean flora in the province of Misiones. The species are described and illustrated, and their geographical distributions are updated. A key to distinguish the Argentinean species of subgen. Rhyncophorum is included, and P. elongata is excluded from the Argentinean Flora. [ABSTRACT FROM AUTHOR]

A new record for argentinian flora, Aristolochia stomachoides Hoehne (Aristolochiaceae) from Misiones province is described and illustrated. Ecological information is given. Its distribution along Paraná River suggests the action of the water as agent of dispersion. [ABSTRACT FROM AUTHOR]

The genus Diastatea (Campanulaceae, Lobelioideae) is recorded for the first time for Argentina in antropic enviroments of the Yungas phytogeographic province (Jujuy), between 1,100 and 2,000 m. We describe and illustrate D. micrantha, the only species collected up to now, including a key to discern it from Lobelia xalapensis, its closest taxon. [ABSTRACT FROM AUTHOR]

The Nevados del Aconquija (5500 m) and Cumbres Calchaquíes (4600 m) are isolated mountain ranges that contain at least three physiognomic units in their eastern slopes: Neotropical rainforests, Andean grasslands and High Andean Steppes. Despite phytogeographical similarities, the two ranges differ in the amount and spatial distribution of rainfall over the elevation gradient. We studied terrestrial small mammals by direct trapping in two altitudinal transects on the eastern slope of the two mountain ranges. We recorded the changes in richness and species composition, as well as the relationships between species and microhabitats at each altitudinal level. The results show a similar structure of the small mammal assemblage in the two ranges. The largest differences, in terms of species composition, were registered at lower elevation forests, and faunal affinities increased with elevation to the point of finding identical species composition at the top of the mountains. Species richness showed a clear curvilinear pattern with a peak at the upper limit of the forests. Our findings suggest that total rainfall has an important influence on the composition and abundance of small mammal species but apparently not on the species richness along the elevation gradient. The highest values of species richness were observed at the sites where a contact between two different physiognomic units exists. These results indicate that habitat heterogeneity plays an important role in allowing the juxtaposition of small terrestrial mammal assemblages of the highlands and lowlands at a given point, contributing significantly to the considerable diversity of species observed in intermediate altitudinal sites. [ABSTRACT FROM AUTHOR]

The most recent studies about the genus Tabebuia and Handroanthus recognize two and six native species in Argentina, and one exotic cultivated species of Handroanthus in urban streets. Nevertheless, the genera are not completely understood, because some taxonomic conflicts are mentioned for the NWof Argentina (NWA). New collections made in Salta and Jujuy, and the revision of an important number of herbarium samples have confirmed a very high variability among the populations of the NWA region, and the subsistence of conflictive situations that prevented the correct identification of the species. Consequently, we considered it was necessary to make the revision of the genus analizing comprehensive material including all the phenological phases, in order to study most characters of every plant organ (young leaves, mature leaves, inflorescences, flowers, fruits and seeds). Our results indicate that the number of native taxa of Handroanthus is seven, including a new variety, and two of Tabebuia. Besides, another cultivated species of Tabebuia was identified, so there are two exotic taxa. All the entities are described, as well as the extant variability of native populations, and their distribution ranges in Argentina are provided. [ABSTRACT FROM AUTHOR]

The survival of Aspidosperma quebracho-blanco juveniles in the Arid Chaco is facilitated under the canopy of nurse plants. The possible effects of nurse plants were studied at intra- and interspecific levels by analysing the spatial distribution of juveniles and adults of A. quebracho-blanco, of the main shrubs Larrea divaricata and Mimozyganthus carinatus, and of the group of deciduous and evergreen shrub species, and their pair associations. Data were analysed using the SADIE (Spatial Analysis by Distance Indices) software. A. quebracho-blanco seedling abundance followed the distribution pattern of the main shade-providing species: an aggregated spatial distribution pattern in most of the categories studied. The seedling bank of A. quebracho-blanco also showed an aggregated pattern and was spatially associated with shrubs and adults of its own species. The intensity of the association depended on the functional types: deciduous Fabaceae, deciduous non-Fabaceae, evergreen and conspecific adults, each of which provides a different canopy structure and therefore different amounts of shade. The spatial association was significant with the evergreen group, and less significant with the deciduous Fabaceae group. There was no positive association with deciduous non-Fabaceae, or with gaps (open sky). The differences generated by canopy cover may influence the nurse effect, as observed in the intensity of association of A. quebracho-blanco with shrubs and conspecific adults. [ABSTRACT FROM AUTHOR]

This is the first complete, floristic analysis of the Asteraceae family from an extense, endangered, subtropical area of Argentina, covered by the Misiones Province. This study reports 88 genera, 345 species and 16 infraspecific taxa of Asteraceae from the two phytogeographic units of Misiones Province: "Selvas Mixtas" District, and "de los Campos" District. Nine species are recorded for first time, and 23 are included as probable records for this area. This paper includes keys for tribes, genera, species and infraspecific taxa, as well as a short discussion about distribution of tribes, genera and habits in relation to political departments or phytogeographic districts. Habit, status, distribution, habitat, vernacular names, uses, and vouchers are given for every taxon. Thirty two taxa are illustrated for the first time. [ABSTRACT FROM AUTHOR]

Vicia macrograminea is confirmed for Argentina precisions about V. epetiolaris, V. graminea var. transiens and V. stenophylla are given. The geographical distribution of V. graminea is extended, and a new variety, Vicia epetiolaris var. microcarpa, is proposed. Also, the presence of V. andicola and V. setifolia in northwestern Argentina is confirmed. A key and illustrations to differentiate all studied species are included. [ABSTRACT FROM AUTHOR]

Materials from Argentina of adventitious species of Viola were examined and four species were confirmed: V. arvensis, V. metajaponica, V. odorata and V. tricolor. V. metajaponica is lectotypified, and the identity of V. japonica is discussed. A key to identify the species, their descriptions, illustrations, ecology and geographic distribution are given. [ABSTRACT FROM AUTHOR]

Petunia interior and P. guarapuavensis are reported for the first time for the Argentinean flora, and their geographical distributions are updated. [ABSTRACT FROM AUTHOR]

This work describes the structure and composition of plant communities from four wetland located in the Copahue Provincial Park (Neuquén Province, Argentina). The study was performed according to the method of the Zürich - Montpellier phytosociological School. Plant communities were distributed along an altitudinal gradient within the inferior montane belt, ranging from 1,400 to 1,800 m, and relationships with the superior montane belt wetlands (1,800 to 2,300 m) were established based on their floristic composition. Four new associations and one subassociation, grouped in the new alliance Juncion lesueurii, arise from the analysis of the syntaxonomical interpretation. [ABSTRACT FROM AUTHOR]

Saevissima group fire ants,Solenopsis richteriandS. invicta, have become serious pests when introduced from Argentina and Brazil to other continents. In South America,Solenopsisare distributed across a great variety of habitats and climates. In North America,S. invicta, introduced free of phorids, now ranges from coast to coast in the south. Success in introducing particularPseudacteonas agents for the biological control of fire ants has varied across climatic zones. We aimed at assembling all the information about fire ant phorids from Argentina and Brazil, to estimate their richness and geographical ranges, to perform a climatic analysis for these distributions, to define groups and climate-based communities, and to test and elucidate Rapoport's biogeographical rule.Argentina and Brazil (South America).From field and museum collections and historical records, we developed a database of fire ant-specific phorids throughout their known geographical range. A total of 123 sites with values for 15 climatic variables were mapped between 10° and 38° SL and between 35° and 65° C WL for the presence/absence of phorids. We calculated species richness across all sites combined, and for each phytogeographical region, using rarefaction curves, and ICE and Mmean estimators. We calculated mid-latitudinal points, geographical ranges and areas for each species. The correlation between mid-latitudinal point and ranges/areas was tested against a null model generated from the randomization of the raw distributional data. We used several types of multivariate analyses to distinguish groups of phorids by phytogeographical regions, hosts and climate, to find gradients of climate throughout the studied area, to define phorid communities in terms of their relationships with gradients of climate, and to test a mechanism for Rapoport's rule.Richness estimations using ICE and Mmean estimators were similar or higher than the observed values depending on the phytogeographical region. Cluster multivariate analyses based on climatic, phytogeographic and host data revealed distinct groupings ofPseudacton. The‘cerrado’ group was confined to tropical savanna areas. A more‘widespread’ group included‘Chaco’ and‘Maritime’ subgroups defined by their respective association with extreme temperatures or precipitation. Ordination multivariate analyses showed (1) two climatic gradients throughout the study area: one of temperature and the other of precipitation, and (2) that climatic variables significantly explained the observed assemblages of phorids. Positive and negative signs of the eigenvalues from the main axes of a canonical correspondence analysis allowed us to define eight communities whose geographical distribution resembled that of phytogeographical regions. We found a significant and positive correlation between geographical areas and mid latitudinal points, and furthermore, the Mantel test based on climatic variables suggested a mechanism for Rapoport's rule applying in the case ofPseudacteon.Pseudacteonspecies with greater mid-latitudinal points occupy broader geographical areas and confront more stressful environmental conditions. Because the composition ofPseudacteoncommunities is largely determined by climatic variables, the correspondence between climates at sites of origin vs. sites of release should be an important consideration in choosing specific phorids for biocontrol efforts. [ABSTRACT FROM AUTHOR]

Cedrela is represented in Argentina by 5 taxa. A new species, Cedrela saltensis, is described and illustrated. A key, descriptions, synonymy, geographical distribution and illustrations of the Argentinian species are also provided. [ABSTRACT FROM AUTHOR]

The presence of the genus Rhipidocladum McClure is confirmed for Argentina, represented by two species. Rhipidocladum neumannii Sulekic, Rúgolo & L.G. Clark sp. nov., found in flowering and vegetative condition in Argentina, in Salta and Tucumán, and Bolivia, is described and illustrated. The presence of R. racemiflorum (Steud.) McClure is documented for the first time for the northwestern region of Salta. Rhipidocladum is described and the differences with the genus Merostachys Spreng. are included in a key. Some remarks about the morphology, flowering, geographical distribution and a doubtful specimen have been made. [ABSTRACT FROM AUTHOR]

The presence of Gloxinia gymnostoma Griseb. and Gloxinia nematanthodes (Kuntze) Wiehler for NW Argentina is reviewed. The first, has been previously cited with mixed materials and in consequence, with incorrect delimitation. Geographical distribution, morphological differences and pollen grain characters between both Argentinian entities of Gloxinia, are briefly pointed out. G. gymnostoma is here lectotypified. [ABSTRACT FROM AUTHOR]