Esta tesis constituye un aporte al conocimiento de la bioes-tratigrafía, paleovegetación y paleoclima de los depósitos paleógenos de la Cuenca de Ñirihuau, en la región del río Foyel. El Grupo El Foyel se integra, de base a techo, por las formaciones Troncoso, Salto del Macho y Río Foyel. En ésta tesis se presenta el primer estudio palinológico detallado de todo el Grupo El Foyel. La edad del mismo, y de cada una de sus formaciones, hasta el momento no ha sido establecida con precisión y ha generado controversias. Los datos esta-dísticos aquí obtenidos refinan el modelo estratigráfico previo basado en relaciones estratigráficas y datos absolutos. Se identificaron más de 106 especies correspondientes a esporas de Bryophyta y Tracheophyta, 11 especies de hongos y 23 de paleomicroplancton de pared orgánica. Se reconocieron 32 palinofacies. Utilizando métodos estadísticos multivariados, las asociaciones de palinofacies fueron agrupadas en palinofacies tipo. Las palinofacies de la Formación Troncoso, sugieren un ambiente marino marginal bajo condiciones de baja energía (palinofacies tipo A) y relativamente más proximal y con descarga fluvial, en la palinofacies tipo B. En las palinofacies tipo C y tipo D (relativamente más dístales) de la Formación Salto del Macho, los fitoclastos sugieren un origen fluviodel-taico, los palinomorfos indican la conexión de cuerpos de agua dulce a salobre en un medio marino marginal, próximo al área de aporte continental y de moderada energía. Condiciones de menor energía y más distales al área de aporte terrígeno deno-tan las palinofacies tipo E y tipo F de la Formación Río Foyel, la gran abundancia de pirita, evidencia el predominio de condi-ciones reductoras. Un ambiente de plataforma somera, relati-vamente estable, es sugerido para esta Formación. El análisis de los esporomorfos refleja para la sección río Foyel estudia-da, la presencia de un bosque regional dominado por Notho-fagaceae, Myrtaceae, Podocarpaceae y Arecaceae, desarro-llado bajo un clima templado a templadocálido y húmedo. En la sección estudiada la relación entre palinomorfos terrestres y marinos es considerada. En la Formación Troncoso, los palino-morfos continentales dominan sobre los marinos. La recurrente presencia de polen de Araucariaceae es indicativa de condi-ciones templadas y húmedas. En la Formación Salto del Macho se produce la retracción del bosque de gimnospermas, asocia-do con la predominancia del bosque de Nothofagus indicativo de condiciones templado húmedas. En la Formación Río Foyel, los esporomorfos indican la presencia de un bosque templado a cálido y húmedo con áreas abiertas subordinadas y un apor-te importante del medio costero. En la Formación Río Foyel, constituida por una sucesión monótona de pelitas negras, los estudios palinológicos permiten reconocer parasecuencias, identificables sobre sus características biofaciales, las que indican somerización ascendente. Los límites de las parase-cuencias son definidas como superficies de inundación que representan ascensos relativos del nivel del mar (superficies de inundación marina) a lo largo del perfil. La Formación Río Foyel muestra secuencias de somerización indicadas por el decrecimiento en abundancia y diversidad de dinoquistes. Dife-rentes superficies de inundación fueron detectadas asociadas con el aumento en abundancia y diversidad en dinoquistes. En general en los eventos regresivos indicados por el decreci-miento en abundancia y diversidad de microplancton marino de pared orgánica, dominan las esporas de pteridofitas y el polen de gimnospermas. A través del perfil, el aumento del polen de Araucariaceae se asocia con un decrecimiento de Nothofagaceae. La influencia marina es registrada por un aumento en abundancia y diversidad de los dinoquistes. En la misma las Nothofagaceae, Myrtaceae, Arecaceae y Poaceae aumentan su abundancia. En la Formación Río Foyel las super-ficies de inundación marina están asociadas a la dominancia de Nothofagaceae sobre el polen de gimnospermas, con una excepción, donde el polen de gimnospermas domina sobre el de Nothofagaceae, probablemente debido a la generación de un gradiente altitudinal. Se comparan para el análisis palinoes-tratigráfico las asociaciones de esporas y polen de las forma-ciones Troncoso, Salto del Macho y Río Foyel, con los regis-tros de los mismos en otras de Patagonia Argentina, Chile, Antártida e Islas Malvinas, usando técnicas de estadística multivariada. La Edad propuesta en base a la información evaluada es, para la Formación Troncoso, Eoceno medio tardío; para la Formación Salto del Macho, Eoceno tardío Oligoceno temprano y, Oligoceno para la Formación Río Foyel (sección inferior) en la sección río Foyel aquí estudiada. / The present dissertation is a contribution to broadening current information on the Palaeogene biostratigraphy, palaeovegetation and paleoenvironment of the Río Foyel section (El Foyel Group), Ñirihuau Basin, Argentina. From base to top, this section includes Troncoso, Salto del Macho and Río Foyel Formations. This is the first detailed palynological study of El Foyel Group. Precise determination of the age of El Foyel Group, and that of its formations, has not been possible so far, and current data remains controversial. The present statistical results refine the previous stratigraphic model, inferred from stratigraphic relations and absolute data. It was possible to recognize 106 taxa of Bryophyta and Tracheo-phyta spores, 11 species of Fungi and 23 species of organic-walled palaeomicroplankton. The data yielded 32 palynofacies. Through multivariate statistical methods (cluster analysis), palynofacies assemblages were grouped into their correspon-ding types. Palynofacies type A, in the Troncoso Formation, suggest the presence of a marginal marine environment under low energy conditions, while palynofacies type B indicate a more proximal environment influenced by fluvial discharge. In palynofacies type C and type D (relatively more distal), from Salto del Macho Formation, phytoclasts suggest a fluvial-deltaic origin, while palynomorphs indicate a connection of fresh water and saline water bodies within a marginal marine environment, close to the continental, lowenergy input area. Palynofacies type E and type F, form the Río Foyel Formation, denote conditions of lower energy and more distal to the terrigenous input area, while the pronounced abundance of pyrites evidences predominant reducing conditions. It is possible to suggest the presence of a relatively stable shallow platform in this Formation. Sporomorph analysis performed in the studied section of El Foyel Group reflects a regional forest dominated by Nothofagaceae, Myrtaceae, Podocarpaceae and Arecaceae, developed under a temperate to warmtemperate and humid climate. The relation between terrestrial/marine palynomorphs is included in the analysis. In the Troncoso For-mation, continental palynomorphs dominate over marine paly-no-morphs. The recurrent presence of Araucariaceae pollen indicates temperate and humid conditions. The Salto del Ma-cho Formation shows a retraction of the gymnosperm forest, associated with the dominance of a Nothofagus forest, indi-cating temperate and humid conditions. The phytoclast group dominates over the amorphous. In the Río Foyel Formation, the sporomorphs indicate the presence of a temperate to warmhumid forest, with subordinate open areas and a remar-kable input from the coastal environment. The Salto del Ma-cho Formation evidences a retraction of the gymnosperm forest, associated with the predominance of the Nothofagus forest, indicative of temperate and humid conditions. In the Río Foyel Formation, sporomorphs suggest the presence of a temperate and humid forest, revealing subordinate open areas and considerable coastal influence. In the Río Foyel Forma-tion, dominated by a homogeneous succession of pelites, palynological analysis led to recognition of the parasequen-ces, identifiable on the basis of the biofacies characteristics, showing upward shallowing. The bounding surfaces of parase-quences are defined as flooding surfaces indicating relative sea level rises (marine flooding surfaces) along the profile.The Río Foyel Formation evidences upward shallowing sequences, indicated by the decrease in abundance and diversity of dinocysts. Different marine flooding surfaces were detected, associated with increasing diversity and abundance of dino-cyst. In general, in the regression events marked by decrea-sing abundance and diversity of organicwalled marine micro-plancton, there is predominance of pteridophyte spores and gymnosperm pollen. Throughout the profile, an increase in Araucariaceae pollen is associated with a decrease in Notho-fagaceae pollen. The abundance and diversity of dinocysts evidence the marine influence. In this event, Nothofagaceae, Myrtaceae, Arecaceae and Poaceae increase in abundance. The marine flooding surfaces in the Río Foyel Formation are associated with the dominance of the Nothofagaceae over the gymnospermous pollen; with one exception, where gym-nosperm pollen dominates over Nothofagaceae, probably due to an altitude gradient. The palinostratigraphic analysis perfor-med for the present work involved a comparison between sporepollen assemblages from Troncoso, Salto del Macho and Río Foyel Formations and analogous registers from formations located at Patagonia Argentina, Chile, Antártida and Falkland Islands. After evaluating results, the following ages were suggested for the different formations: MiddleLate Eocene for Troncoso Formation; Late EoceneEarly Oligocene for Salto del Macho Formation; and Oligocene for the studied section of the Río Foyel Formation (lower section).

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Identification of pollen in fecal pellets is a potential technique for describing an animals diet and in turn the vegetation of an area. Mule deer and Bighorn Sheep pellets representing both summer and winter browsing and a variety of habitats were examined using relative percentages and the absolute pollen frequencies. In addition, fossil pellets from Stanton's Cave, Grand Canyon, Arizona, were examined and compared with modern pellets. Absolute pollen frequencies of individual pellets showed higher values and greater variation for summer pellets than for winter pellets. Relative pollen percentages for a specific vegetation type showed more variation in fecal pellets than in soil surface samples. Unless specifically being eaten, arboreal pollen types such as Pinus are less abundant in fecal pellets than in soil samples. Unlike soil surface samples, arboreal pollen types in fecal pellets are frequently limited to the immediate source area.

La région du lac Mégantic est probablement la première zone à s'être déglacée au Québec, ce qui lui confère un intérêt particulier. L'analyse pollinique et anthracologique des sédiments des trois lacs situés à ses abords, soit les lacs Clinton, Dubuc et des Joncs ont permis de reconstituer l'histoire locale et régionale de la végétation et des feux. La présence d'un gradient altitudinal a entrainé des décalages surtout dans l'instauration des premières phases forestières. La région s'est déglacée vers 13 500 ans AA, et une toundra s'y est installée. Le début de l'afforestation est marqué par l'arrivée du sapin baumier et de l'épinette noire. Par la multiplication de leurs populations, la forêt s'est fermée vers 10 000 ans AA pour constituer une forêt boréale qui fût alors perturbée par plusieurs épisodes de feux. Vers 8000 ans AA, les nouvelles conditions climatiques favorisent les espèces feuillues et instaurent une érablière à bouleau jaune et une diminution de la fréquence des feux. Les résultats obtenus permettent d'enrichir les connaissances paléophytogéographiques et anthracologiques du Québec. / The Lac Mégantic area is probably the first deglaciated in Quebec (13,500 cal. BP) which gives it a special interest. The pollen and charcoal analysis in sediments of three lakes located in its vicinity, Clinton, Dubuc and des Joncs Lakes, helped to reconstruct postglacial vegetation and fire, locally and regionally. The presence of an altitudinal gradient resulted in some delays in the introduction of various forest stages especially at the beginning. At start, tundra established in the region. The start of the afforestation is marked by the arrival of the balsam fir and black spruce. By multiplying their populations, the forest closed around 10,000 years cal. BP to build a boreal forest and was also disturbed by multiple fires. By 8,000 years cal. BP, new conditions favored deciduous species and created a sugar maple and yellow birch forest associated with lower fire frequencies. This study offers new perspectives in fire and forest reconstitutions by using proximal sites.

This thesis summarizes palynological and paleontological study of the middle part of the Cracow Sandstone Series which is divided into the Łaziska (Bolsovian) and the Libiąz Beds (Asturian). Samples were obtained from the borehole G5 Dab nearby Jaworzno from both coal and non-coal sediments. Palynological study confirmed the stratigraphical gap between these two beds by observation of dissapearance of nine miospore taxons at the bottom of the Libiąz Beds (Torispora, Converrucosisporites, Schulzospora, Gillespieisporites, Schopfites, Convolutispora, Cristatisporites, Tripartites, Cingulizonates). Different ecological demands during the coal and non-coal sedimentation were confirmed. The sedimentation of the Łaziska coal seams is characterized by alternation of lycospore and densospore phases which confirmes alternation of the contrasting plant assamblages with a predominance of the arborescent lycopsids Lepidodendron and Lepidophloios and sub-arborescent lycopsid Omphalophloios. Arborescent lycopsids preferred planar (rheotrophic) mires. Plant assamblages with predominance of the lycopsid Omphalophloios colonized drier peat swamps with fluctuating water level (ombrothrophic). Peat swamp vegetation in Libiąz Beds was damper with localy transitional phase with increased incidence of the genus...

La carotte KZai02, forée dans le cône détritique sous-marin du fleuve Zaire/Congo, renseigne du stade isotopique 6.6 à l’Actuel (derniers 165 ka). La dynamique de la végétation de l’Afrique Centrale a été reconstruite sur la base de l’étude de son contenu pollinique. Ces résultats, comparés à ceux du contenu en carbone organique total et au rapport Ti/K, renseignent respectivement sur l’activité des alizés et l’intensité de la mousson dans le passé. Les glaciaires sont caractérisées par des températures basses empêchant le développement de la forêt tropicale humide sur le bassin versant du Zaïre/Congo au bénéfice des savanes. Les interglaciaires sont marquées par le développement de la forêt tropicale humide et des marais de mangrove sur la côte suite à l’élévation du niveau marin. Le passage progressif de zones herbeuses à des environnements plus forestiers témoigne d’un décalage entre les augmentations de température et d’humidité. Le stade isotopique 5 montre deux événements moins chauds (sous-stades 5b et 5d) avec le développement des forêts afromontagnardes (principalement Podocarpus). L’excentricité, l’obliquité et particulièrement la précession ont été identifiées comme ayant exercé une influence sur les écosystèmes végétaux. Ces périodicités ont été interprétées en termes de variations des précipitations liées à des fluctuations de l’ITCZ. Des cycles infra-Milankovitch ont aussi été révélés par l’analyse spectrale. Ils sont attribués (1) aux pulsations glaciaires des événements de Heinrich et de Dansgaard/Oeschger et (2) à des variations à haute fréquence semblables à celles décelées sur la mousson est-asiatique et reliées au contrôle des calottes polaires / Core KZai02 from the Zaire/Congo deep sea fan runs from MIS 6.6 to Present (last 1685 ka). Its pollen study allows to reconstruct the vegetation past variations over the Central Africa. These results, compared to the Total Organic Carbon content (TOC) and the Ti/K ratio, inform on the past trade winds and West African monsoon variability, respectively. During glacials, low temperatures over the Zaire/Congo watershed prevented the development of the tropical rain forest in opposition to savannah. Each interglacial starts with the development of mangrove testifying to events of sea-level rise. Then, the succession of grassy and forested environments indicates a gap between temperature and humidity rises. During the warmer episodes, rain forest expanded over the Central Africa. The Marine Isotope Stage 5 includes two cooler events supported by expansion of the afromontane forest (mainly Podocarpus) corresponding to substages 5b and 5d. Eccentricity, obliquity and particularly precession are identified in variations of the ecological groups of the KZai 02 pollen record and interpreted in terms of variations of precipitations linked to fluctuations of the ITCZ. Sub-Milankovitch periods are also revealed by spectral analysis and related to (1) the Heinrich and Dansgaard/Oeschger glacial pulsation events and (2) high frequency variations similar to the East Asian monsoon oscillations controlled by ice sheets

Cette étude concerne un long enregistrement sédimentaire marin (Site DSDP 380 : Miocène supérieur à Présent) et des affleurements à terre de dépôts marins ou lacustres du Miocène supérieur et(ou) du Pliocène inférieur. L’objectif principal de cette recherche est de reconstruire la végétation et le climat des régions nord-anatolienne et nord-égéenne des 7 derniers Ma. Deux types de végétation y furent alternativement : les forêts de plantes thermophiles et les formations ouvertes incluant les steppes à Artemisia. A la fin du Miocène, la plupart des éléments mégathermes (tropicaux) et mégamésothermies (subtropicaux) avaient régressé en raison des détériorations climatiques. Cependant, certains d'entre eux ont survécu pendant le Pliocène supérieur, notamment ceux qui constituaient des forêts littorals marécageuses (Glyptostrobus, Engelhardia, Sapotaceae, Nyssa) ou participaient à des forêts mixtes avec des arbres décidus mésothermes. Pendant ce temps, les formations ouvertes à herbes sont devenues prédominantes dans la végétation sans que les éléments steppiques (Artemisia, Ephedra, Hippophae rhamnoides) soient très abondants. A 2,6 Ma, sous l’effet des premières glaciations arctiques, les éléments méga-mesothermes se sont très raréfiés malgré la persistance de quelques reliques (Taxodiaceae : probablement Glyptostrobus, Engelhardia, Sapotaceae, Nyssa). Simultanément, les forêts mixtes à éléments mésothermes (Quercus décidus, Betula, Alnus, Liquidambar, Fagus, Carpinus, Tilia, Acer, Ulmus, Zelkova, Carya, Pterocarya, etc) ont aussi quasiment disparu tandis que les environnements steppiques se développaient fortement. Désormais, tout au long des cycles glaciaire-interglaciaire (d’abord de 41 ka de périodicité puis de 100 ka), les steppes à Artemisia occuperont plus d’espace temporel que les phases arborées. Depuis 1,8 Ma, les environnements à herbes et les steppes à Artemisia n’ont cessé de s’étendre jusqu' à aujourd'hui. Cette expansion des steppes à Artemisia dans la région du Pont-Euxin a été observée au tout début du Pliocène mais leur premier enregistrement en Anatolie date du Miocène inférieur. Le développement de la steppe à Artemisa en Anatolie pourrait résulter du soulèvement du Plateau tibétain. Le maintien dans cette région de plantes thermophiles reliques en situation de refuges (Carpinus orientalis, Pterocarya, Liquidambar orientalis, Zelkova) peut être expliqué par l’influence grandissante de la mousson asiatique dont le renforcement aurait aussi résulté du soulèvement du Plateau tibétain. / This study concerns a long marine section (DSDP Site 380: Late Miocene to Present) and onshore exposed sections from the Late Miocene and/or Early Pliocene. The main target of this study is to reconstruct vegetation and climate in the North Anatolia and North Aegean region for the last 7 Ma. Two vegetation types were alternately dominant: thermophilous forests and open vegetations including Artemisia steppes. During the Late Miocene, most of the tropical and subtropical plants declined because of the climatic deterioration. However, some of them survived during the Late Pliocene, such as those which constituted coastal swamp forests (Glyptostrobus, Engelhardia, Sapotaceae, Nyssa) or composed deciduous mixed forests with mesothermic trees. Simultaneously, herbaceous assemblages became a prevalent vegetation component despite steppe elements (Artemisia, Ephedra, Hippophae rhamnoides) did not significantly develop. At 2.6 Ma, as a response to the onset of Arctic glaciations, subtropical elements rarefied despite some taxa persisted (Glyptostrobus, Engelhardia, Sapotaceae, Nyssa). In parallel, deciduous mixed forest assemblages composed of mesothermic trees (deciduous Quercus, Betula, Alnus, Liquidambar, Fagus, Carpinus, Tilia, Acer, Ulmus, Zelkova, Carya, Pterocarya) almost disappeared too while steppe environments strongly enlarged. Then, Artemisia steppic phases developed during longer temporal intervals than mesophilous tree phases all along the glacial-interglacial cycles (first with a period of 41 kyrs, then 100 kyrs). Since 1.8 Ma, herbaceous ecosystems including Artemisia steppes still continuously enlarged up today. Such an expansion of Artemisia steppes in the Ponto-Euxinian region was observed at the earliest Pliocene but their earliest settlement in Anatolia seems to have occurred in the Early Miocene. The development of the Artemisa steppes in Anatolia might result from the uplift of the Tibetan Plateau. Relictuous plants such as Carpinus orientalis, Pterocarya, Liquidambar orientalis, Zelkova persisted up today. This story can be explained by some influence of the Asian monsoon which reinforced as a result from the uplifted Tibetan Plateau.

M.Sc. (Geology) / Please refer to full text to view abstract

Au cours de la première moitié de l’Holocène les conditions climatiques, eustatiques et anthropiques connaissent de nombreuses et importantes modifications. Parmi celles-ci, les données. Parmi celles-ci, les données régionales relatives au quart nord-ouest du bassin méditerranéen révèlent plusieurs variations pluriscalaires et significatives des conditions d’humidité ainsi que des températures. Parallèlement, la hausse du niveau marin enregistre des vitesses très élevées et la région de l’arc Liguro-Provençal voit l’installation des premières communautés agro-pastorales de la culture « Impressa », en l’occurrence dès le début du 6ème millénaire cal. BCE. Afin de qualifier la réponse de la végétation alluviale côtière, entre la fin du 8ème et le 5ème millénaire, face à l’évolution de ces conditions, l’analyse pollinique à haute résolution de deux séquences sédimentaires alluviales (bassin du Loup et de la Cagne) à été réalisée. Grâce à une approche pluridisciplinaire (carpologie, ostracologie, sédimentologie…) et méthodologique inédite (analyse du transport pollinique fluviatile) les résultats montrent une évolution précise des écosystèmes végétaux côtiers et alluviaux. Au sein de cette évolution, la remontée du niveau marin joue un rôle fondamental comme en témoigne l’expansion littorale des aulnaies marécageuses. Le forçage climatique joue également un rôle important. Les étés plus humides du 6ème millénaire participe à la diffusion du sapin à basse altitude, alors que l’augmentation de la fréquence des sécheresses estivales enregistrées à partir du 5ème millénaire favorise le développement d’une végétation sclérophylle à bruyère arborescente. La néolithisation de la région participe également au façonnage des paysages littoraux. La récurrence du type pollinique Cerealia (gr. Hordeum) dès les premières décennies du 6ème millénaire atteste de l’importance des plaines alluviales côtières dans l’économie de production des premiers groupes néolithiques. / This study investigates the impact of climate and sea level changes and the anthropogenic perturbations on the alluvial vegetation in the Mediterranean French coastal plains during the early to mid Holocene. Between 7000 and 3700 BCE, the combination of different type of regional proxy records reveal significant changes in the humid conditions and temperatures. These records also reveal rapid sea level changes and the first Neolithic settlement (5800 caL. BCE) in Southeastern France (« Impressed ware culture »). High resolution pollen data from two cores sampled in the alluvial plains of the Cagne and the Loup Rivers enable to study the vegetation responses to these changes. Thisstudy employed a pluridisciplinary approach (carpology, study of ostracods, sedimentology…) and developed a new ethodology for the assessment of the fluvial pollen transport. The results reveal a significant connection between the vegetation structure from the coastal area and the sea level changes. This relationship explains the alder expansion in the swamp area. Moreover the results also reveal the effects of the humid summer conditions on the vegetation dynamics and explain the spruce expansion during the sixth millennium BCE as well as the expansion of the sclerophyllous vegetationduring the fifth millennium BCE. The impact of the Neolithic agriculture on the alluvial land cover started with the first ecades of the sixth millennium BCE. Thanks to the frequencies of the pollen grains of cereals (Hordeum gr.) and the pollen vidence of forest decline between 6000 and 3700 BCE, the results show the significance of the Mediterranean coastal area in the Neolithic economy.

É apresentada aqui a revisão taxonômica das espécies de Viguiera Kunth que ocorrem no Brasil, com inclusão de descrições, ilustrações, mapas de distribuição e comentários. Também são providas chaves de identificação para grupos relacionados e para as espécies sul-americanas. O estudo da anatomia foliar forneceu novos subsídios para a delimitação de espécies ou grupo de espécies. As análises polínicas também apresentam informações parciais úteis à taxonomia. Foi elaborada uma investigação sobre Viguiera sensu lato, através de três análises envolvendo diferentes números de táxons terminais, com uso de dados morfológicos; a primeira visou o esclarecimento da real posição taxonômica de seus representantes e as duas últimas pleitearam uma melhor delimitação dos grupos de espécies no continente. A análise dos padrões de distribuição geográfica possibilitou a delimitação de dois grupos com características morfológicas distintas, além de um intermediário; o primeiro exclusivo da região dos Andes, o segundo extra-andino e o terceiro andino com pequenas intrusões em outras localidades. Os resultados também corroboram a hipótese de outros autores, de que a origem do gênero é recente no Brasil. Em relação às condições edáficas, existem dois grupos de espécies no Brasil; o primeiro encontrado em regiões com clima do tipo Cwa e o segundo no clima do tipo Aw, da classificação de Köpen; apenas 4 espécies ocorrem em clima Cfa, mas não são exclusivamente brasileiras. Não houve respaldo para a transferência das espécies sul-americanas para o gênero Rhysolepis. / This study presents a taxonomic review of the species Viguiera Kunth that occur in Brazil, and includes descriptions, illustrations, distribution maps and comments. Identification keys are also provided for related groups and to the South American species. The leaf anatomy study supplied new subsidies for the delimitation of the species or of species groups. The pollinic analysis either presents useful partial information in taxonomy. An investigation was elaborated on Viguiera sensu lato, through three analyses, involving different numbers of terminal taxa and using morphological data; the first one tried to explain the real taxonomic position of its representative members and the last two sought for a better delimitation of the groups of species in the Continent. The analysis of the patterns of geographic distribution made possible the delimitation of two groups with different morphological characteristics, and a intermediate one; the first group is exclusive from Andean region, the second not happens in the Andes, and the third do not occur in the Andes, with a few intrusions in other localities. The results also corroborate others author\'s hypothesis, that the origin of the genus is recent in Brazil. In relation of the edaphic conditions, there are two groups of species in Brazil: the first one is found in regions with climate of the type Cwa and the second in the climate of the type Aw, of the Köpen classification; only 4 species happen in climate Cfa, but they are not exclusively Brazilian. There was no support for the transfer of the South American species to the genus Rhysolepis.