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Asteraceae subfamily Barnadesioideae (ten genera, c. 90 species), confined to South America, are sister to the remainder of the family. The relative antiquity of the barnadesioids might lead one to expect that they contain more wood features plesiomorphic for the family, but only one character clearly falls in that category. Pits on imperforate tracheary elements are bordered (except for annuals), whereas simple pits occur in two related families, Calyceraceae (part) and Stylidiaceae (all that have been examined); in Goodeniaceae bordered pits only occur. By attaining fully bordered pits in Chuquiraga, the imperforate tracheary elements qualify as an apomorphy, ‘neotracheids’, valuable for resisting embolism formation in dry and cold South American habitats. Neotracheids are found also in Loricaria (Asteraceae: Inuleae), also from these habitats. Neotracheids, like plesiomorphic tracheids, are conductive, unlike fibre tracheids and libriform fibres. Other barnadesioid wood characters adapted to cold and drought include grouping of vessels, high vessel density, shorter vessel elements and helical sculpture (including helical thickenings on lumen-facing walls) of secondary xylem vessels. In Chuquiraga and Dasyphyllum, these helical thickenings are bordered in some species (new report for angiosperms). Some of the barnadesioid adaptations to cold and drought can be found in North American Artemisia spp. (Asteraceae: Anthemideae), especially in montane and desert areas. Wood features of barnadesioids match their respective habits and habitats: a few trees; shrubs of humid, dry or desert areas; a distinctive rhizomatous succulent in the pampas (Schlechtendalia); a scree/gravel perennial (Huarpea) and two genera of annuals, one with succulent leaves (Duseniella) and one with rayless (at least at first) stems in arid and open soils (Doniophyton). Diversity is unusual considering the small size of the subfamily. Examples of endodermal crystals (Arnaldoa only), pith sclereids and primary xylem fibres are cited.

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

Morphological features of the heads (capitula) of Asteraceae have been used extensively in classification of the family at different levels of the taxonomic hierarchy. Among the various characters, features of stamens have been employed to determine relationships from specific to tribal levels, including size, shape, colour, cell size and shape of the thecae, downwards extensions from the thecae (spurs or tails), the apex and base of the connective between the thecae, the antheropodium that joins the connective to the filament and the filament itself. We investigate variation in these staminal features in 88 species of ten genera of Asteraceae subfamily Barnadesioideae, the sister group of the rest of the family. A new morphological categorization of antheropodia and anther bases is presented, features that show the widest ranges of variation in the subfamily. Other characters, such as apices of the connectives and fusion of filaments, are less variable. Six staminal characters are optimized on a molecular phylogenetic tree for Barnadesioideae. Putative plesiomorphies for the ancestor of the subfamily are hypothesized to be entire apices of the connectives, antheropodia shorter than the basal appendages and filaments free and glabrous. The ancestral conditions for pollen sac extension and for attachment of anthers on the corolla tube are equivocal. Hypotheses are offered on the possible adaptive function of staminal features, such that antheropodia seem significant in structural support of the thecal tube and that spurs and tails may function in protecting the basal portion of the thecae from insect probing.

Hieracium reitzianum Cabrera ex Urtubey, a new species of Asteraceae from southeastern Brazil, is described and illustrated. This species is placed within Hieracium L. sect. Hypochaeridiformia (Arv.-Touv. ex Peter) Zahn (Hieracium subg. Chionoracium Sch. Bip.) by the presence of ciliate corolla lobes. It is most readily distinguished from other species of the section by having broadly obovate to suborbicular leaves with rounded to obtuse apices.

Chryselium Urtubey & S. E. Freire, a new monotypic genus, is here described and illustrated to accomodate one species that was initially placed in Helichrysum, H. gnaphalioides, as Chryselium gnaphalioides. The new genus, Chryselium, is a monoecious herb with single stems and terminal capitulescences that are densely glomerulate from the Tropical Andes of Venezuela, Colombia, Ecuador, Bolivia, and Peru. This genus differs fundamentally from Helichrysum by having a stoloniferous habit and corollas with purple apices. Amolecular analysis using DNA sequences from nuclear (ITS and ETS) markers placed this genus in a clade with Chevreulia, Cuatrecasasiella, Antennaria, and Diaperia in the FLAG group. Affinities of the new genus with genera previously assigned to Chryselium are also discussed. Fil: Freire, Susana Edith. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Botánica Darwinion. Academia Nacional de Ciencias Exactas, Físicas y Naturales. Instituto de Botánica Darwinion; Argentina Fil: Urtubey, Estrella. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Botánica Darwinion. Academia Nacional de Ciencias Exactas, Físicas y Naturales. Instituto de Botánica Darwinion; Argentina

The genus Hypochaeris was likely introduced into South America by a unique long-distance dispersal event from an ancestral Northwest African species, with subsequent radiation and diversification throughout the temperate zones of the continent. Hypochaeris catharinensis is an endemic species of Southern Brazil growing mostly in high-elevation grasslands with dry, rocky, and shallow soils. Here, we used nine microsatellite loci and a total sample of 441 individuals to assess genetic variability patterns within and among 13 H. catharinensis populations. The results showed a total of 215 alleles in the nine loci tested, the expected and observed heterozygosities average were 0.31 and 0.43, respectively, and allelic richness varied from 4.09 to 7.23. The levels of allelic richness showed that genetic variability is maintained by gene flow, thus ensuring that these populations are not genetically isolated. We found no correlation between geographic and genetic distances, with high levels of genetic variability within, rather than among, populations. The low levels of genetic structure in the species are consistent with recent evolutionary processes of the Hypochaeris genus in South America; after adaptive radiation and species differentiation, dispersal to similar habitats led to the establishment of new populations. Along with initial founder effects, the existence of gene flow explains the current genetic variation across the H. catharinensis populations. In addition, historic environmental changes reported for Southern Brazil may explain the current clustered distribution of the species.

El texto ofrece a los estudiantes de grado de ciencias naturales, agrarias y forestales un panorama de las plantas terrestres del mundo. agrupadas en categorías sistemáticas y en un contexto filogenético. Esta compilación sintetiza el estudio de las cuatro grandes entidades vegetales tradicionales: briofitas, pteridofitas, gimnospermas y angiospermas. Estos cuatro grupos incluyen la gran mayoría de la flora conocida, en un número cercano a las 300.000 especies, de las cuales alrededor de diez mil son briofitas, otras 10.000 son pteridofitas unas 600 son gimnospermas, y las restantes, casi 280.000 son angiospermas. A partir de la diversidad presentada, se destacan los grupos con representantes en el país, ubicándolos en el contexto fitogeográfico argentino y se contemplan además las especies cultivadas más destacadas. Se incluyen cinco capítulos sobre el aporte de la sistemática al conocimiento de la biodiversidad en el marco de la situación actual, enfatizándose las herramientas teóricas que permiten la producción de este tipo de conocimiento desde una perspectiva histórica y práctica. Cada capítulo está acompañado de lecturas sugeridas y actividades que le permiten al estudiante aplicar los conocimientos adquiridos., Facultad de Ciencias Naturales y Museo

The genus Hypochaeris has a recent evolutionary history caused by long-distance dispersal in conjunction with adaptive radiation in the South American continent. Hypochaeris lutea is a perennial herb that grows mostly at altitudes of around 1000 m in cold swamps of the southern regions of Brazil. We investigated the amplified fragment length polymorphism (AFLP) in 270 individuals representing 11 Brazilian populations of H. lutea to elucidate the population genetic structure of this species. The frequencies of polymorphic loci and gene diversity ranged from 83.42% to 91.66% and from 0.26 to 0.34, respectively. Analysis of molecular variance revealed that most of the genetic variability was found within (76.67%) rather than among (23.3%) populations, agreeing with the pattern of genetic distribution within and among populations observed in other allogamous species of Hypochaeris. A Mantel test showed no correlation between genetic and geographic distances when all populations were considered. Simulations performed using a Bayesian approach consistently identified two clusters with different admixture proportions of individuals, as also revealed by a UPGMA dendrogram of populations. The pattern of genetic structure observed in H. lutea is consistent with a process of successive colonization events by long-distance dispersal resembling the rapid and recent radiation that has been proposed to explain the origin of the South American species of Hypochaeris.

Premise of the study: We developed microsatellite markers to study clonal growth and interspecific hybridization in the Patagonian and subantarctic plant Hypochaeris incana (Asteraceae) and its closest relatives. Methods and Results: We developed primers for microsatellite loci from 454 sequence reads of genomic DNA of H. incana. We tested them on individuals of H. acaulis, H. hookeri, H. incana, H. palustris, and H. tenuifolia. We selected 15 polymorphic microsatellite loci, which delivered clearly scorable fragments in most or all species. With mean values between 0.7 and 0.8, the expected heterozygosity in populations of H. incana is high. Conclusions: Due to high levels of polymorphism, the developed markers make it possible to distinguish between genets and ramets in H. incana. In some markers, null alleles complicate the scoring of genotypes in tetraploids. All of the developed markers are suitable to study interspecific hybridization among this group of closely related species. Fil: Wang, Ping. University of Natural Resources and Life Sciences; Austria Fil: Tremetsberger, Karin. University of Natural Resources and Life Sciences; Austria Fil: Urtubey, Estrella. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Botánica Darwinion. Academia Nacional de Ciencias Exactas, Físicas y Naturales. Instituto de Botánica Darwinion; Argentina Fil: Bernhardt, Karl-Georg. University of Natural Resources and Life Sciences; Austria

Premise of the study: We developed microsatellite markers to study clonal growth and interspecific hybridization in the Patagonian and subantarctic plant Hypochaeris incana (Asteraceae) and its closest relatives. Methods and Results: We developed primers for microsatellite loci from 454 sequence reads of genomic DNA of H. incana. We tested them on individuals of H. acaulis, H. hookeri, H. incana, H. palustris, and H. tenuifolia. We selected 15 polymorphic microsatellite loci, which delivered clearly scorable fragments in most or all species. With mean values between 0.7 and 0.8, the expected heterozygosity in populations of H. incana is high. Conclusions: Due to high levels of polymorphism, the developed markers make it possible to distinguish between genets and ramets in H. incana. In some markers, null alleles complicate the scoring of genotypes in tetraploids. All of the developed markers are suitable to study interspecific hybridization among this group of closely related species.

The Lucilia group sensu Anderberg and Freire comprises nine South American genera: Belloa, Berroa, Chevreulia, Cuatrecasasiella, Facelis, Gamochaetopsis, Jalcophila, Lucilia and Luciliocline. The aims of this contribution were, using DNA sequences from plastid (rpl32-trnL, trnL-F) and nuclear (ITS and ETS) markers, together with morphological characters, to test the monophyly of the Lucilia group and provide new insight into generic circumscriptions. Our studies, including a broad taxon sampling of Gnaphalieae species, suggest that the Lucilia group is paraphyletic, since Antennaria, Chionolaena, Gamochaeta, Loricaria, Micropsis, Mniodes and Stuckertiella are all nested within the Lucilia group. Morphology and molecular analyses combined showed that the traditional generic circumscription of most of the genera (e.g., Berroa, Chevreulia, Chionolaena, Cuatrecasasiella, Facelis, Jalcophila and Micropsis) correlates with the inferred phylogenetic relationships. Conversely, Lucilia and Luciliocline are non-monophyletic. Lucilia is nested in a clade with Berroa, Facelis and Micropsis. Luciliocline is strongly embedded within the clade Belloa pp + Mniodes. Our results are consistent with Dillon’s study that considered Belloa as a montotypic genus (B. chilensis). Luciliocline and the remaining species of Belloa are accommodated in the genus Mniodes, and the necessary combinations are proposed for the expanded Mniodes. All the analyses showed that the monotypic genera Stuckertiella and Gamochaetopsis are in a well-supported clade nested within Gamochaeta, which implies that taxonomic changes are required also for these genera. Internal relationships in the group and the key morphological characters used in the taxonomy of the group, as well as incongruences found between morphological and molecular analyses, are discussed. Fil: Freire, Susana Edith. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Botánica Darwinion. Academia Nacional de Ciencias Exactas, Físicas y Naturales. Instituto de Botánica Darwinion; Argentina Fil: Chemisquy, Maria Amelia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina Fil: Anderberg, Arne A.. Swedish Musem of Natural History; Suecia Fil: Beck, Stephan G.. Universidad Mayor de San Andrés; Bolivia Fil: Meneses, Rosa I.. Universidad Mayor de San Andrés; Bolivia Fil: Leouille, Benoît. Universidade de Sao Paulo; Brasil Fil: Urtubey, Estrella. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Botánica Darwinion. Academia Nacional de Ciencias Exactas, Físicas y Naturales. Instituto de Botánica Darwinion; Argentina

Gamochaeta beckii, a new species found in La Paz, Bolivia is described and illustrated. Gamochaeta beckii is similar to G. purpurea but it is easily distinguished by stems branched from the base to the inflorescence, oblanceolate leaves, the small capitula arranged in glomerules, forming leafy short and continuous spikes, and short acuminate inner phyllary apices. A key to the species of Gamochaeta occurring in Bolivia is presented.

Hypochaeris is an excellent system for studying different modes of chromosome evolution in plants. We carried out a cytogenetic analysis on populations of 2 Hypochaeris species, comprising 10 populations of H. catharinensis and 5 of H. lutea, to assess possible changes on chromosome organization in this interesting genus. Conventional Feulgen staining and fluorescent banding revealed that the general aspects of chromosome morphology for all populations of both species were similar, evidence of the typical bimodal karyotypes with 2n = 8 chromosomes that characterize the South American Hypochaeris. Comparative analysis of the karyotypes identified minor variations in the absolute size and arm ratio of corresponding chromosome pairs. One population of H. lutea was entirely polyploid adding a novel cytotype to this species. Fluorescent banding revealed strong chromomycin A3 (CMA3)-positive signals on both arms of chromosomes 3 and 4 of H. catharinensis, revealing a new pattern for the distribution of GC-rich heterochromatin in Hypochaeris. A strong CMA-positive signal was observed on the short arm of chromosome 3 in one population of H. lutea, while the other populations validated the CMA3 pattern already described for this species. While the overall karyotype similarities of the 2 species are in compass with all South American Hypochaeris, the presence of unusual large blocks of GC-rich heterochromatin suggests that chromosome rearrangements, related to dispersion of heterochromatin, are taking place in the karyotype of H. catharinensis. The novel polyploid cytotype identified in H. lutea provides support that polyploidization is an active process in the mode of chromosome evolution in Hypochaeris. Fil: Fiorin, F. G.. Universidade Estadual de Londrina; Brasil Fil: Ruas, P. M.. Universidade Estadual de Londrina; Brasil Fil: Ortiz, M. A.. Universidad de Sevilla; España Fil: Urtubey, Estrella. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Botánica Darwinion; Argentina Fil: Matzenbacher, N. I.. Universidade Federal do Rio Grande do Sul; Brasil Fil: Ruas, C. F.. Universidade Estadual de Londrina; Brasil

Gamochaeta (tribe Gnaphalieae, Asteraceae) is composed of ca. 60 species primarily distributed in tropical and subtropical America. Within the tribe Gnaphalieae, the genus is characterized by capitula arranged in spikes or head-like clusters, few hermaphroditic central florets, truncate style branches with apical sweeping trichomes, pappus bristles connate at the base into a ring falling as a unit, and achenes with globose twin trichomes. Previous molecular phylogenetic studies have suggested the paraphyly of the genus, but have not provided a basis for redefining generic limits due to incomplete taxon sampling. To address this problem, DNA sequences from the plastid (trnL-F) and nuclear (ETS and ITS) genomes were analyzed from a broad taxon sample representing the full range of morphological variation known in the genus. Our results affirm that Gamochaeta is paraphyletic as presently circumscribed. Two clades can be recognized: one clade that includes the majority of the species currently assigned to Gamochaeta and a second clade that includes Gamochaetopsis, Stuckertiella and seven species of Gamochaeta. We present here a new circumscription of Gamochaeta, including two new combinations, Gamochaeta alpina and Gamochaeta peregrina, and the resurrection of Gamochaeta capitata. Our results also show Omalotheca supina, O. norvegica and O. sylvatica, which were placed by some authors in Gamochaeta or in Gnaphalium, form a monophyletic group distantly related to both genera., Facultad de Ciencias Agrarias y Forestales

In order to elucidate the biotic diversification of Asteraceae inhabiting the South American Transition Zone, we undertook a panbiogeographic analysis (based on a parsimony analysis of endemicity) and a cladistic biogeographic analysis. The study units were the six biogeographic provinces of this zone plus the seven subregions of the Neotropical and Andean regions, considered as “outgroups”. Species analyzed belonged to the genera Arnaldoa, Barnadesia, Belloa, Berroa, Chevreulia, Chuquiraga, Cuatrecasiella, Dasyphyllum, Doniophyton, Duseniella, Facellis, Fulcaldea, Gamochaetopsis, Huarpea, Hypochaeris, Jalcophila, Lucilia, Luciliocline, and Schlechtendalia. A parsimony analysis of endemicity, based on presence/absence data of the 66 individual tracks ranged on two or more areas, allowed to identify four generalized tracks: (1) Coastal Peruvian Desert and Puna provinces; (2) Central Chilean, Patagonian, and Subantarctic subregions; (3) Amazonian, Chacoan, and Parana subregions; and (4) Puna province and Parana and Chacoan subregions. The Puna and Parana provinces, connected with two different generalized tracks each, constitute nodes. A cladistic biogeographic analysis, based on the paralogy–free subtrees extracted from the taxonomic area cladograms of Barnadesia, Chuquiraga, Dasyphyllum, Hypochaeris, and the Lucilia group, allowed obtaining a general area cladogram, which indicates a basic separation between the Atacama, Monte, and Prepuna provinces closely related to the Andean region, and the North Andean Paramo, Coastal Peruvian Desert, and Puna provinces closely related to the Neotropical region. Our results corroborate once again the transitional character of the provinces assigned to the South American Transition Zone, and allow speculating on their close affinities with the Andean and Neotropical regions. Fil: Urtubey, Estrella. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Botánica Darwinion. Academia Nacional de Ciencias Exactas, Físicas y Naturales. Instituto de Botánica Darwinion; Argentina Fil: Stuessy, Tod F.. Universidad de Viena; Austria Fil: Tremetsberger, Karin. Universidad de Sevilla; España Fil: Morrone, Juan José. Universidad Nacional Autónoma de México; México

The Hypochaeris sessiliflora complex (Asteraceae, Cichorieae) consists of nine species of the genus from South America (all in section Achyrophorus Scop.) that have sessile or nearly sessile flowering heads surrounded by a rosette of leaves. They occur at 1430–5100 m in elevation along the Andean chain from Venezuela to Chile and Argentina. Two species, H. sessiliflora Kunth and H. meyeniana (Walp.) Benth. & Hook. f. ex Griseb., are extremely polymorphic, and they vary conspicuously in the shape of the external phyllaries and presence or absence of different types of trichomes. They have the widest distributions (Venezuela to central Peru, and Peru to northern Chile and northwestern Argentina, respectively), they flower throughout the year, and they also are primarily associated with dry and sunny habitats. Hypochaeris meyeniana is characterized by retrorsely pinnatifid leaves (rarely lobate) and slightly narrower cypselar apices. Hypochaeris hohenackeri (Sch. Bip.) Domke and H. taraxacoides Ball...

We used Amplified Fragment Length Polymorphism markers (AFLP) and breeding system studies to investigate the population structure and reproductive biology of Hypochaeris angustifolia (Asteraceae: Cichorieae). This species is endemic to altiplanos of the Atlas Mountains (Morocco) where it occurs in scattered populations, and it is the sister species to c. 40 species of this genus in South America. PCoA, NJ, and Bayesian clustering, revealed that the populations are very isolated whilst AFLP parameters show that almost all populations have marked genetic divergence. We contend that these features are more in accord with a vicariance origin for the scattered populations of H. angustifolia, rather than establishment by long-distance dispersal. The breeding system studies revealed that H. angustifolia is a self-incompatible species, with low fecundity in natural and in experimental crosses, probably due to a low frequency of compatible phenotypes within and between the populations.

Subfamily Barnadesioideae (Asteraceae) consists of nine genera and 91 species endemic to South America. They include annual and perennial herbs, arching shrubs and trees up to 30 m tall. Presumed sister to all other Asteraceae, its intergeneric relationships are key to understanding the early evolution of the family. Results of the only molecular study on the subfamily conflict with relationships inferred from morphology. We investigate inter- and intrageneric relationships in Barnadesioideae with novel DNA sequence data and morphological characters using parsimony, likelihood and Bayesian inference. All results verify Barnadesioideae as monophyletic and sister to the rest of the family. A basal split within the subfamily is recognized, with Chuquiraga, Doniophyton and Duseniella in one clade, and Arnaldoa, Barnadesia, Dasyphyllum, Fulcaldea, Huarpea and possibly Schlechtendalia in another. The largest genus, Dasyphyllum, is revealed as biphyletic with the two clades separating along subgeneric and geographic lines. Schlechtendalia, suggested as the earliest diverging lineage of the subfamily by morphological studies and parsimony analyses, is found in a more derived position under model-based inference methods. Competing phylogenetic hypotheses, both previous and present, are evaluated using likelihood-based tests. Evolutionary trends within Barnadesioideae are inferred: hummingbird pollination has developed convergently at least three times. An early vicariance in the subfamily’s distribution is revealed. X = 9 is supported as the ancestral base chromosome number for both Barnadesioideae and the family as a whole.

In an attempt to delineate the area of origin and migratory expansion of the highly successful invasive weedy species Hypochaeris radicata, we analysed amplified fragment length polymorphisms from samples taken from 44 populations. Population sampling focused on the central and western Mediterranean area, but also included sites from Northern Spain, Western and Central Europe, Southeast Asia and South America. The six primer combinations applied to 213 individuals generated a total of 517 fragments of which 513 (99.2%) were polymorphic. The neighbour-joining tree presented five clusters and these divisions were supported by the results of Bayesian analyses: plants in the Moroccan, Betic Sierras (Southern Spain), and central Mediterranean clusters are all heterocarpic. The north and central Spanish, southwestern Sierra Morena, and Central European, Asian and South American cluster contain both heterocarpic (southwestern Sierra Morena) and homocarpic populations (all other populations). The Doñana cluster includes two homocarpic populations. Analyses of fragment parameters indicate that the oldest populations of H. radicata are located in Morocco and that the species expanded from this area in the Late Quaternary via at least three migratory routes, the earliest of which seems to have been to the southwestern Iberian Peninsula, with subsequent colonizations to the central Mediterranean area and the Betic Sierras. Homocarpic populations originated in the southwestern Iberian Peninsula and subsequently spread across north and central Spain, Central Europe and worldwide, where they became a highly successful weed.

In this study, we describe the development and screening of an enriched genomic DNA library aiming to identify microsatellite loci in Hypochaeris catharinensis, an endemic species from southern Brazil. Twelve polymorphic microsatellite loci tested in a sample of 60 individuals from three different populations of H. catharinensis, identified 98 alleles with an average of 8.17 alleles per locus. The average polymorphic information content (PIC) varied from 0.098 to 0.757, with five loci exhibiting significant deviation from Hardy–Weinberg equilibrium (HWE). Transferability test for cross-amplification was done in 10 related Hypochaeris species with a rate of success ranging from 12 loci, for H. petiolaris and H. varigata, to six loci for H. patagonica. These microsatellite loci will provide valuable information for studying genetic diversity, population genetic structure, conservation biology and for understanding the past demographic events of H. catharinensis and other related species of Hypochaeris. Hypochaeris is considered as a biological model to understand evolutionary processes in the vascular flora of South America, particularly from the temperate portion of the continent. As suggested by molecular clock dating, the South American species of Hypochaeris was derived from a common ancestor from northwest Africa that arrived in the continent between 3.5 and 0.25 mya by long-distance dispersal

Hypochaeris is thought to have arrived in South America by dispersal over the Atlantic Ocean from NW Africa during the Pliocene or Pleistocene. We used amplified fragment length polymorphism (AFLP) to unravel specific limits and relationships in the South American group of Hypochaeris (c. 45 species). The Moroccan endemic Hypochaeris angustifolia, which is sister to the entire South American group, was used as outgroup. Our AFLP analysis comprises 415 individuals from 32 South American species and is based on six primer combinations with 670 fragments scored. It provides important information for the delimitation of species and detection of closely related species pairs or groups. Most species are monophyletic and supported with > 90% bootstrap proportion. Hybridization is suggested between Hypochaeris chillensis and H. microcephala in Brazil. The internal nodes (or "backbone") of the tree are not highly supported, but six major phylogenetic groups (also showing similarity in distribution and growth form) center around Hypochaeris apargioides, H. chondrilloides, H. microcephala, H. pampasica, H. sessiliflora, and H. tenuifolia. These results suggest that rapid migration into different geographical regions played an important role in the initial diversification of Hypochaeris in South America.

Pollen of Proustia (10 specimens examined) and Lophopappus (12 specimens examined) (Asteraceae, Mutisieae) are described as part of an analysis of the classification of these genera. Their exine structure is determined and compared with structures found in other genera of Mutisieae (25 specimens examined and data of other authors), in order to clarify the subtribal position of Proustia and Lophopappus. Pollen of Proustia and Lophopappus have the following characters in common: Grains radially symmetrical and isopolar; tricolporate, long colpi with a microgranulate membrane, endoaperture lalongate with acute or bifurcate equatorial ends; subprolate or prolate-spheroidal; elliptic or spheroidal; polar caps conspicuous or not so distinctive, and exine microechinate. Two types of sexine structure are observed: (1) Trixis type, with two columellate ramified sublayers, the inner sublayer thicker than the outer one (found in Lophopappus berberidifolius, L. tarapacanus, Proustia cuneifolia var. cuneifolia, P. cuneifolia var. mendocina, P. cuneifolia var. mollis, P. ilicifolia var. baccharoides, and P. pyrifolia); and (2) Proustia type, with two equally thick sublayers of ramified columella (found in Lophopappus blakei, L. cuneatus, and L. foliosus). Proustia ilicifolia var. ilicifolia and Lophopappus peruvianus have both types of sexine structure. Pollen analysis of other genera of Mutisieae subtribes Nassauviinae, Mutisiinae and Gochnatiinae demonstrate two new exine types: (1) Ainsliaea type, with two sublayers poorly distinguishable, the exine appearing compact, the outer surface microechinate; and (2) Wunderlichia type, with two well-differentiated sublayers, the outer surface echinate, the spines with apical channels. The results show that: (1) Proustia and Lophopappus cannot be differentiated from each other by pollen characters; (2) the genera of subtribe Nassauviinae can be differentiated from the other two subtribes by having sexine sublayers with similar structure; (3) Proustia and Lophopappus have the pollen exine structural types that are typical of pollen of subtribe Nassauviinae; (4) subtribes Gochnatiinae and Mutisiinae are characterized by having sexine sublayers with different structures; but (5) those two subtribes cannot be differentiated based on pollen characters.

ISSN 0046-0262. Previous molecular sequence and restriction site data have confirmed subfamily Barnadesioideae as basal within Asteraceae. The subfamily consists of 88 species in nine genera: Arnaldoa, Barnadesia, Chuquiraga, Dasyphyllum, Doniophyton, Duseniella, Fulcaldea, Huarpea, and Schlechtendalia. Two morphological cladistic analyses among genera or subgeneric groups within this subfamily have been completed previously, with contrasting results. Because of the importance of understanding relationships in this group of early Asteraceae, especially for insights on character evolution within the family, comprehensive morphological cladistic analyses were conducted at the specific level. Initial investigations utilising 31 characters with all 88 species led eventually to curtailed studies with 52 species. Five different outgroup hypotheses were employed: Acicarpha laxa, A. spathulata, Calycera leucanthema, C. spinulosa (all Calyceraceae), and Schlechtendalia luzulaefolia (Barnadesioideae; as functional outgroup). The results confirm Schlechtendalia as basal within Barnadesioideae. Monophyly is also confirmed for all genera, sections Chuquiraga and Acanthophyllae of Chuquiraga, and subgenus Archidasyphyllum of Dasyphyllum. All cladograms show two major groups (although statistical support values are low): (1) Chuquiraga, Doniophyton and Duseniella; and (2) Arnaldoa, Dasyphyllum, Fulcaldea, Huarpea and Barnadesia. Although bilabiate (4 + 1) corollas occur in Schlechtendalia, tubular corollas are believed plesiomorphic for the subfamily because they are pervasive in Calyceraceae as well as in all other basal Barnadesioideae. Pollen with no shallow depressions also are hypothesised as plesiomorphic for Barnadesioideae, even though one depression occurs in Schlechtendalia. A southern South American origin of Barnadesioideae (and the entire family) is re-emphasised. The previously hypothesised ancient lineage of Dasyphyllum subg. Archidasyphyllum, consisting of large trees, appears more derived in the new analyses.

The pollen morphology of 59 species of the genera Arnaldoa, Barnadesia, Chuquiraga, Dasyphyllum, Doniophyton, Duseniella, Fulcaldea, Huarpea and Schlechtendalia belonging to the Barnadesioideae has been studied with light and scanning electron microscopy. Three main pollen types were recognized: (1) lophate pollen found in Barnadesia and Huarpea ; (2) pollen with intercolpal depressions in Arnaldoa and some species of Dasyphyllum (subtypes I, II and III) and Schlechtendalia ; and (3) pollen without depressions found in Chuquiraga, Dasyphyllum p.p., Doniophyton, Duseniella and Fulcaldea . In Dasyphyllum cryptocephalum and D. tricophyllum , we recognized a new type with 21–23 depressions. A key for the identification of pollen types is presented. Phylogenetic significance of the three palynological characters (morphology, sculpture and structure) is interpreted through phylogenies of Barnadesioideae proposed by earlier workers. Cladograms show the monophyletic group Barnadesia–Huarpea supported by a smooth exine and lophate pollen. Our results show that the 1-layered exine represents a synapomorphy for Dasyphyllum, Arnaldoa, Fulcaldea, Barnadesia and the Huarpea group.

A taxonomic revision of Oxalis section Palmatifoliae is presented, together with cluster analyses to clarify the limits of the species. This monophyletic section includes five species endemic from Southern Argentina and Chile. A key for the species, descriptions, illustrations, synonymy, and geographical distribution for each species are also provided. Five lectotypifications and two new synonymies are proposed.

The genus Hypochaeris offers an excellent model for studies of recent adaptive radiation in the South American continent. We used karyotype analysis with chromomycin A3 (CMA3)/4',6-diamidino-2-phenylindole (DAPI) banding and fluorescence in situ hybridization (FISH), and amplified fragment length polymorphism (AFLP) fingerprinting to investigate for the first time the Brazilian endemic H. catharinensis and define its position within the South American group of species. Strong CMA-positive signals were seen at the end of both arms of chromosome 3 and at the end of the long arm of chromosome 4. DAPI bands were only detected in subterminal position on short arm of chromosome 4. FISH with 5S and 35S ribosomal DNA (rDNA) probes revealed a single 5S rDNA locus on short arm of chromosome 2, typical for all other South American Hypochaeris taxa analyzed to date. The 35S rDNA locus was identified at subterminal position on the short arm of chromosome 3, as reported so far for only two of the known species (H. lutea and H. patagonica). The AFLP study included 55 individuals, comprising nine species of the South American Hypochaeris plus their putative ancestor H. angustifolia. Eleven AFLP primer combinations generated a total of 401 fragments, of which 388 (96.7%) were polymorphic. High genetic similarities were observed among taxa, with all South American Hypochaeris species falling into one main cluster [100% bootstrap (BS)]. Hypochaeris catharinensis is closely related to H. lutea (82% BS), forming a well-separated subcluster within the South American species. Taken together, the karyological and AFLP data contribute to the placement of H. catharinensis within the phylogenetic framework of South American species of Hypochaeris and allow the definition of a novel and well-resolved phylogenetic group (the Lutea group). Fil: Reck, Maikel. Universidade Estadual de Londrina; Brasil Fil: Benício, Lucas M.. Universidade Estadual de Londrina; Brasil Fil: Ruas, Eduardo Augusto. Universidade Estadual de Londrina; Brasil Fil: Alves Rodrigues, Luana. Universidade Estadual de Londrina; Brasil Fil: Ruas, Paulo Maurício. Universidade Estadual de Londrina; Brasil Fil: Ortiz, María A.. Universidad de Sevilla; España Fil: Talavera, Salvador. Universidad de Sevilla; España Fil: Urtubey, Estrella. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Botánica Darwinion. Academia Nacional de Ciencias Exactas, Físicas y Naturales. Instituto de Botánica Darwinion; Argentina Fil: Stuessy, Tod. Universidad de Viena; Austria Fil: Weiss Schneeweiss, Hanna. Universidad de Viena; Austria Fil: Tremetsberger, Karin. Universidad de Viena; Austria. University of Natural Resources and Life Sciences; Austria Fil: Michelan, Vanessa S.. Universidade Estadual de Londrina; Brasil Fil: Matzenbacher, Nelson Ivo. Universidade Federal do Rio Grande do Sul; Brasil Fil: Vanzela, André L. L.. Universidade Estadual de Londrina; Brasil Fil: Terrab, Anass. Universidad de Sevilla; España Fil: Samuel, Rose. Universidad de Viena; Austria Fil: Ruas, Claudete Fátima. Universidade Estadual de Londrina; Brasil

We report the phylogeographic pattern of the Patagonian and Subantarctic plant Hypochaeris incana endemic to southeastern South America. We applied amplified fragment length polymorphism (AFLP) and chloroplast DNA (cpDNA) analysis to 28 and 32 populations, respectively, throughout its distributional range and assessed ploidy levels using flow cytometry. While cpDNA data suggest repeated or simultaneous parallel colonization of Patagonia and Tierra del Fuego by several haplotypes and/or hybridization, AFLPs reveal three clusters corresponding to geographic regions. The central and northern Patagonian clusters (approximately 38-51 degrees S), which are closer to the outgroup, contain mainly tetraploid, isolated and highly differentiated populations with low genetic diversity. To the contrary, the southern Patagonian and Fuegian cluster (approximately 51-55 degrees S) contains mainly diploid populations with high genetic diversity and connected by high levels of gene flow. The data suggest that H. incana originated at the diploid level in central or northern Patagonia, from where it migrated south. All three areas, northern, central and southern, have similar levels of rare and private AFLP bands, suggesting that all three served as refugia for H. incana during glacial times. In southern Patagonia and Tierra del Fuego, the species seems to have expanded its populational system in postglacial times, when the climate became warmer and more humid. In central and northern Patagonia, the populations seem to have become restricted to favourable sites with increasing temperature and decreasing moisture and there was a parallel replacement of diploids by tetraploids in local populations.

Se entregan datos citológicos del número cromosómico diploide de 24 especies de la flora vascular de Chile, utilizándose material de raíces provenientes de plántulas. Nuevos registros para la flora de Chile son: Alstroemeria presliana Herb. subsp. presliana (2n = 16), Chaetanthera moenchioides Less. (2n = 26), Hypochaeris scorzonerae (DC.) F.Muell. (2n= 8), Phycella bicolor (Ruiz et Pav.) Herb. (2n = 16) y Rhodophiala tiltilensis (Traub et Moldenke) Traub (2n = 16). Chromosome numbers of 24 Chilean taxa of vascular plants were studied using root-tip mitotic metaphases. New records for the chilean Flora are: Alstroemeria presliana Herb. subsp. presliana (2n = 16), Chaetanthera moenchioides Less. (2n = 26), Hypochaeris scorzonerae (DC.) F.Muell. (2n = 8), Phycella bicolor (Ruiz et Pav.) Herb. (2n = 16) and Rhodophiala tiltilensis (Traub et Moldenke) Traub (2n = 16).

The genus Hypochaeris (Asteraceae, Lactuceae) contains twelve species in Europe, three in Asia, and approximately 50 in South America. In this paper, we worked with mitotic chromosomes of three different species of Hypochaeris from Chile: H. acaulis, H. incana and H. scorzonerae. The species are very different in morphology and geographic distribution. The aim of this work was to compare the chromosome morphology of these species. We found that the chromosomes are different in size and morphology in H. acaulis (smaller than 6 μm and only chromosome 3 having a secondary constriction on the short arm). In H. incana and H. scorzonerae the chromosomes are very similar in size, and chromosomes 2 (on the long arm) and 3 (on the short arm) contain secondary constrictions. A tetraploid is reported for H. scorzonerae BBVA Fundación Alexander von Humboldt (Georg Foster Stipendium)

One hundred and thirty-seven new chromosome counts are reported from 104 populations of 26 native South American taxa of Hypochaeris (Asteraceae, Lactuceae), together with two invasive Mediterranean species: H. glabra and H. radicata. First reports are provided for seven taxa (H. alba, H. cf. eremophila, H. caespitosa, H. hookeri, H. parodii, H. patagonica and H. pinnatifida) and one new ploidy level is reported (diploid for H. incana, so far known only as a tetraploid). Including the results of this study, the chromosomes of 39 of the c. 50 Hypochaeris species known from the New World have now been counted. Most species are diploid with 2n = 2x = 8 and have bimodal, asymmetrical karyotypes. Tetraploidy (2n = 4x = 16) is reported here for the first time in H. caespitosa. Infra-specific polyploidy (probably autopolyploidy) is reported in H. incana and H. taraxacoides, both cases including infra-populational cytotype mixtures (2x and 4x). Polyploidy is now known from eight South American Hypochaeris species (c. 16%). Basic karyotype analyses allow the placement of the newly counted taxa into previously proposed but slightly modified groupings and provide the framework for further molecular cytogenetic analyses. The reported findings suggest that chromosomal change in South American Hypochaeris, in contrast to Old World species, has not involved aneuploidy, but polyploidy and/or more subtle changes in chromosome length, perhaps via satellite DNA amplification/deletion or activity of retroelements, and rDNA reorganization., Facultad de Ciencias Naturales y Museo