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Urbanization results in biodiversity-damaging land use change since it is normally associated with reduced vegetation cover and installation of artificial lights. Light pollution raises illumination levels of night skies and affects the behaviour of hawkmoths and their interactions with plants. In addition to feeding on flowers, adult hawkmoths require adequate daytime resting sites and specific host plants on which their caterpillars can feed. In this study, we assessed the relationships of light pollution and tree cover with pollen load and plant fitness of Erythrostemon gilliesii, a legume native to Argentina which exclusively depends on pollination by long-proboscid hawkmoths. We determined stigmatic pollen load, and seed and fruit set at six sites in Central Argentina. Plants growing in sites with highest light pollution and lowest tree cover received the least pollen loads on their stigmas. Where tree cover was lowest, germinated pollen load and plant fitness were lowest, even where light pollution was low. We found that light pollution together with tree cover may affect pollination, thus indirectly influencing the fitness of nocturnally pollinated plants. However, the indirect influence of light pollution on plant fitness may be dependent on the conservation status of neighbouring natural habitats, since in low light-polluted sites, tree cover seems to be the major factor influencing plant fitness.

Pollination interactions between plants bearing oil-flowers and oil-collecting bees are regarded as specialized, and within the major group of bees, oil-collecting bees are considered a special functional group of pollinators, yet they encompass a great diversity, not only at taxonomic level but also in morphological and behavioral aspects. Since the functional group of oil-collecting bees is functionally diverse, we examined whether these bees, despite their gross commonalities, may be exerting divergence within and among oil-flowered species or, alternatively, promoting convergence to some general oil-flower morphology that can be pollinated by a functional range of oil-bees. To answer this question, we recorded pollinator assemblages of 18 taxa of Nierembergia, as well as the foraging behavior, visitation frequency, and morphometric characterization of all oil-collecting bees species that pollinate the flowers of those taxa, by field observations and sampling. We found that the pollinator assemblages of the species and varieties of Nierembergia largely differed among taxa. 14 species of oil-collecting bees, belonging to the genera Chalepogenus, Centris, Tapinotaspis, Caenonomada, Tetrapedia, and Arhysoceble, were recorded as pollinators of Nierembergia flowers. These pollinator species varied in multivariate body size, rewards-gathering behavior, and way they carry out pollination on flowers. According to our results, Nierembergia flowers are pollinated by five functional groups of oil-collecting bees that presumably promote divergence within and among Nierembergia taxa. Floral resource-harvesting behavior of oil-collecting bees species that pollinate Nierembergia flowers would be a key feature in the definition of functional groups and in the diversification of flower features in Nierembergia.

Light pollution represents a widespread long-established human-made disturbance and an important threat to nocturnal pollination. Distance from the niche centroid where optimal environmental conditions join may be related to species sensitivity to habitat change. We estimated the environmental suitability of the plant species Erythrostemon gilliesii and of its guild of hawkmoth pollinators. We considered the overlap of suitability maps of both partners as the environmental suitability of the interaction. We used a three-year record of ten E. gilliesii populations to calculate pollination intensity as the number of individuals that received pollen per population. In addition, for each population, we measured the distance to the high light pollution source around a buffer of 15 km radius. Finally, we predicted pollination intensity values for environmental suitability ranging from 0 to 1, and distance to high light pollution sources ranging from 0 to 56 Km. Pollination intensity decreased along an axis of increasing environmental suitability and increased with distance to sources of light pollution. The highest values of pollination intensity were observed at greatest distances to sources of light pollution and where environmental suitability of the interaction was lowest. The prediction model evidenced that, when environmental suitability was lowest, pollination intensity increased with distance to sources of high light pollution. However, when environmental suitability was intermediate or high, pollination intensity decreased away and until 28 km from the sources of high light pollution. Beyond 28 km from the sources of high light pollution, pollination intensity remained low and constant. Populations under conditions of low environmental suitability might be more likely to respond to disturbances that affect pollinators than populations under conditions of high environmental suitability.

Floral scent is a key communication channel between plants and pollinators. However,the contributions of environment and phylogeny to floral scent composition remain poorly understood. In this study, we characterized interspecific variation of floral scent composition in the genus Jaborosa Juss. (Solanaceae) and, using an ecological niche modelling approach (ENM), we assessed the environmental variables that exerted the strongest influence on floral scent variation, taking into account pollination mode and phylogenetic relationships. Our results indicate that two major evolutionary themes have emerged: (i) a ?warm Lowland Subtropical nectar-rewarding clade? with large white hawkmoth pollinated flowers that emit fragrances dominated by oxygenated aromatic or sesquiterpenoid volatiles, and (ii) a ?cool-temperate brood-deceptive clade? of largely fly-pollinated species found at high altitudes (Andes) or latitudes (Patagonian Steppe) that emit foul odors including cresol, indole and sulfuric volatiles. The joint consideration of floral scent profiles, pollination mode, and geoclimatic context helped us to disentangle the factors that shaped floral scent evolution across ?pollinator climates? (geographic differences in pollinator abundance or preference). Our findings suggest that the ability of plants in the genus Jaborosa to colonize newly formed habitats during Andean orogeny was associated with striking transitions in flower scent composition that trigger specific odor-driven behaviors in nocturnal hawkmoths and saprophilous fly pollinators. Fil: More, Marcela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Soteras, María Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Ibañez, Ana Clara. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Dötterl, Stefan. Paris-lodron-university Of Salzburg; Austria Fil: Cocucci, Andrea Aristides. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Raguso, Robert A.. Cornell University, Dept. Of Neurobiology And Behavior; Estados Unidos

Biotic and abiotic context may affect the intensity of interspecific interactions and subsequently drive locally particular phenotypic selection patterns on interacting traits. We evaluated the geographical variation of matching traits of the brush‐type flowers of Caesalpinia gilliesii and of the proboscis length of its guild of hawkmoth pollinators, as well as their relation with environmental variables. We assessed the geographical variation of interacting traits (style and filament vs. mean proboscis length of the guild of hawkmoths) across seven populations, and estimated phenotypic selection on the plant side. Interacting traits showed similar relationships with environmental variables. Phenotypic selection on the plant side was influenced by proboscis length and by environmental conditions. Mean proboscis length of the guild was shorter than previously recorded for the same study area thus probably shifting the selective optima of flower length. We observed two presumptive coevolutionary cold spots where one‐sided negative directional selection is acting on style length. The lack of selection on the pollinator‐side should be further confirmed. We provided joint evidence, mostly lacking, about the geographical variation of selective pressures on the plant side associated with both proboscis length and abiotic conditions. We suggest that recent environmental change may be shifting floral length optima. Fil: Soteras, María Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Rubini Pisano, Malén Alué. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Bariles, Julieta Belén. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Moré, Marcela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Cocucci, Andrea Arístides. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina

Introduced plants become decoupled from their usual pollinators and by relying on resident pollinator species or other reproductive strategies become established in new areas, spread and, eventually, invade. Here, using breeding system experiments, we studied the reproductive biology of the bird-pollinated South American species Nicotiana glauca across native and non-native areas, both inside and outside the range of flower-visiting birds. In the native range, where the species is visited by hummingbirds, open cross-pollinated flowers set as many seeds and almost as many fruits as open pollination controls, suggesting that pollinators make a major contribution to reproductive success. In South Africa, the flowers were pollinated by sunbirds which, although less efficiently, also contributed to N. glauca reproduction, replacing hummingbirds. In contrast, in Mallorca, where nectar feeding birds are absent, fruit production in open cross-pollinated flowers was near zero, and significantly lower than in open pollination controls, suggesting that reproduction is almost entirely by autonomous self-pollination. Hand-pollination experiments showed that the species is self-compatible throughout its range. Pollinator exclusion experiment showed that N. glauca relies on self-pollination only in pollinator poor areas, where plants have a much higher capacity for autonomous self-pollination than elsewhere. A reduction in anther-stigma distance does not seem to account the higher self-pollination capacity in the non-native environment without pollinators. Despite probable evolutionary adaptation, and flexibility in pollinator association and mating system, seed production in the introduced range was somewhat pollen limited, suggesting that the mismatch between N. glauca and its novel pollination environment might retard invasion., Funding for this research was provided by the National Research Council of Argentina (CONICET), the National Ministry of Science and Technology of Argentina, the Department of Science and Technology of South Africa and the Spanish Research Council (CSIC).

Gradual vs punctuated and unidirectional (only lengthening) vs. bidirectional (lengthenings and shortenings) modes of evolution are explanations that compete to explain adaptive changes of flower tube length in angiosperm. The nightshade genus Salpichroa Miers, with 21 species mostly growing in the tropical Andes of southern South America, has the opportune qualities of including nearly 15-fold inter-specific variation in corolla tube length, as well as one species that is a candidate for participating in evolutionary escalation with the longest-billed hummingbird, Ensifera ensifera. We reconstructed the phylogenetic relationships using five molecular markers, the two plastid markers trnD-trnT and trnL, and three nuclear markers, ITS and two COSII, and estimated divergence times of the genus in order to reconstruct the history of both corolla tube length and pollination mode (i.e. hummingbirds, moths or multiple). We used comparative methods to determine whether corolla tube elongation/shortening is associated with shifts in pollination mode and to test, modes and rates of corolla tube change. We found evidence of both lengthening and shortening of corolla tubes. Evolutionary rates are consistent with rapid corolla tube length transitions that are only partly associated with shifts in pollination mode. Though punctuated evolution (i.e. large changes predominantly at speciation events) explained corolla changes in the whole genus, gradual evolution (i.e. gradual changes during a coevolutionary race with the same pollinator) was a better explanation for the change in the long-flowered clade, mostly pollinated by hummingbirds. Fil: Ibañez, Ana Clara. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: More, Marcela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Salazar Chávez, Gerardo Adolfo. Universidad Nacional Autónoma de México. Departamento de Botánica. Instituto de Biología; México Fil: Leiva González, Segundo. Universidad Privada Atenor Orrego. Museo de Historia Natural; Perú Fil: Barboza, Gloria Estela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Cocucci, Andrea Aristides. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina

The adaptive accuracy of flowers in the context of pollination can be used to address the relationships between flower phenotype (fundamental pollination accuracyand precision) and realized accuracy and precision (interaction of floral parts with a pollinator). Here we tested whether effectiveness (number of pollen grains transported per visit) and realized male and female accuracy and precision differ between two hummingbird pollinator species (Heliomaster furcifer and Sappho sparganura) that pollinate the ornithophilous liana Dolichandra cynanchoides. Although the hummingbird species did not differ in the frequency of flower visitation, H. furcifer carried pollen on a narrower spot of the head and deposited significantly more pollen on a restricted zone of artificial stigmas − representative of the true stigma − compared with S. sparganura. Flower structure exhibited similar accuracy with regard to pollen deposition on and retrieval from pollinators. Functional flower depth matched significantly with the bill of the hummingbird exhibiting the highest precision and accuracy. This suggests that mechanical reciprocal fit may be responsible for the better pollination performance of H. furcifer. In this study we show that differences in realized accuracy and precision may explain evolutionary responses to pollinator specialization in a single pollinator species within functional groups. Fil: Poblete Palacios, Javier Alejandro. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina Fil: Soteras, María Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Cocucci, Andrea Aristides. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina

Flower phenotype may diverge within plant lineages when moving across “pollinator climates” (geographic differences in pollinator abundance or preference). Here we explored the potential importance of pollinators as drivers of floral color diversification in the nightshade genus Jaborosa, taking into account color perception capabilities of the actual pollinators (nocturnal hawkmoths vs. saprophilous flies) under a geographic perspective. We analyzed the association between transitions across environments and perceptual color axes using comparative methods. Our results revealed two major evolutionary themes in Jaborosa: (1) a “warm subtropical sphingophilous clade” composed of three hawkmoth-pollinated species found in humid lowland habitats, with large white flowers that clustered together in the visual space of a model hawkmoth (Manduca sexta) and a “cool-temperate brood-deceptive clade” composed of largely fly-pollinated species with small dark flowers found at high altitudes (Andes) or latitudes (Patagonian Steppe), that clustered together in the visual space of a model blowfly (Lucilia sp.) and a syrphid fly (Eristalis tenax). Our findings suggest that the ability of plants to colonize newly formed environments during Andean orogeny and the ecological changes that followed were concomitant with transitions in flower color as perceived by different pollinator functional groups. Our findings suggest that habitat and pollination mode are inextricably linked in the history of this South American plant lineage. Fil: Moré, Marcela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Ibañez, Ana Clara. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Drewniak, María Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Cocucci, Andrea Aristides. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Raguso, Robert A.. Cornell University; Estados Unidos

The large body of work on the adaptation of plants to pollinators is still somewhat incomplete because most studies focus on one-to-one interactions. How will adaptation proceed in a multi-pollinator environment? According to Stebbins' Most Effective Pollinator Principle, ‘the characteristics of the flower will be moulded by those pollinators that visit it most frequently and effectively.’ To test this hypothesis, we studied the pollination biology of Pelargonium incrassatum (Geraniaceae) in the Namaqualand Region of Southern Africa. This species has a long floral tube and we expected its most important pollinator to have a long proboscis. Contrary to expectations, the most important pollinator was a short proboscid fly (a new species of Prosoeca), while Prosoeca peringueyi, which had a proboscis that matched the floral tube length, was a rare visitor. Consistent with the high degree of trait mismatching, we did not detect selection on tube length at most sites. The paradox of mismatching traits can be resolved by considering the strength of the trade-off involved. Adaptation to the rare species can apparently occur without incurring the cost of reduced pollination by the abundant species. Generally, species may often evolve specialized morphology if they do not incur the cost of ecological specialization. Fil: Pauw, Anton. University Of Stellembosch; Sudáfrica Fil: Cocucci, Andrea Aristides. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Sersic, Alicia Noemi. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina

Learning plays an important role in the location and utilization of nectar sources for pollinators. In this work we focus on the plant-pollinator interaction between the butterfly Agraulis vanillae (Nymphalidae) and two Glandularia plant species (Verbenaceae) that grow in sympatry. Bioassays using arrays of artificial flowers (red vs. lilac-purple) showed that naïve A. vanillae butterflies do not have innate colour preferences for any of the tested colours. Trained butterflies were able to learn to associate both floral colours with the presence of nectar rewards. Wild A. vanillae butterflies visited the red flowers of Glandularia peruviana much more frequently than the lilac-purple flowers of Glandularia venturii. Standing nectar crop measurements showed that G. peruviana flowers offered three times more sucrose than the flowers of G. venturii. Analyses confirmed that corolla colour of G. peruviana (red flowers)and G. venturii (lilac-purple flowers) were discriminable in the butterfly?s colour space. These findings may indicate flexibility in A. vanillae preferences due to a learned association between red coloration and higher nectar rewards. Fil: Drewniak, María Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Briscoe, Adriana D.. Department Of Ecology And Evolutionary Biology; Estados Unidos Fil: Cocucci, Andrea Aristides. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Beccacece, Hernán Mario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Centro de Investigaciones Entomológicas de Córdoba; Argentina Fil: Zapata, Adriana Inés. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Cátedra de Diversidad Animal I; Argentina Fil: Moré, Marcela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina

Due to drastic changes in pollinators between native and invaded habitats, we might expect that pollinator-mediated selection on floral traits of alien plants differ from that in their native ranges. Here, through geometric morphometric tools and phenotypic selection analyses, we examined whether adaptation in flower shape and length occurred in Nicotiana glauca as a response to pollinator selection in contrasting pollination environments. We assessed populations of this plant species in the native range (South America), where plants depend on hummingbird pollination, and in two invaded areas, one where sunbirds act as pollinators (South Africa), and another where nectar feeding birds are absent and reproduction is entirely by autonomous self-pollination (Mallorca, Spain). Corolla length and shape varied significantly among pollination environments. Non-native sites were less variable and their range of variation fell within the native range of variation. Flower length in native populations and in a South African population matched the bill length of their respective pollinators. In contrast with the straight floral tubes in the native range, both non-native areas had significantly curved tubes. Curvature may improve the fit with the curved bills of sunbirds in South Africa (versus straight beaks of hummingbirds) and may enhance self-pollination in Mallorca, but this similarity between invaded areas may equally be due to drift and a shared colonization route. We found spatial variation in selection acting on corolla length but not on corolla shape. Overall, selection patterns were not consistent with floral trait variation. Although some results are consistent with both drift and selection, our study suggests that population divergence in flower shape and length is more likely the result of long-term diversifying pollinator-driven selection, which is difficult to detect by studying a single selection event., AAC, ANS, SBV and VP acknowledge the National Research Council of Argentina (CONICET) and the Universidad Nacional de Córdoba (UNC) as researchers. This work was supported by FONCyT (PICT 2015-3089; PICT-2011-0837) to ANS, the Department of Science and Technology of South Africa (438 75946) and the Spanish Ministry of Economy and Competitiveness (CGL2013-44386-P).

Taxonomic diagnostic floral structures can be very informative about details of the floral mechanism, promoting baselines for inferences about pollination system. In a number of species in the milkweed tribe Marsdenieae, the already complex basic asclepiad flower structure is further elaborated by the evolution of one morphological novelty: the anther skirt. Since the functional significance of this trait is poorly understood, we investigate its role in the pollination mechanism on Marsdenia megalantha. We tested the phenotypic integration of anther skirt; we described its functional anatomy; we identified and recorded the function of its nectaries; we described and tested in laboratory its contribution to the pollination mechanism; and we studied the pollination effectiveness of this system. The characteristics of an anther skirt are essential in the noctuid pollination of M. megalantha. This is due to its particular morphological and anatomical features related to its ability both to secrete at night and to contain nectar independently from the stigmatic chamber. The skirt also functions coordinately with the corona as a funnel that directs the noctuid legs to gynostegium. Its effectiveness in producing pollination was confirmed by field observations and manipulative experiments. We suggest that nectar offers at night and mechanical adjustment may be applicable to other representatives of the tribe as a feature that determines noctuid pollination, assigning a functional value for the anther skirt beyond the taxonomy. Fil: Domingos-Melo, Arthur. Departamento de Botanica, Laboratario de Biologia Flora; Brasil Fil: Nadia, Tarcila L.. Núcleo de Biologia - Centro Acadêmico de Vitória, Unive; Brasil Fil: Wiemer, Ana Pia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Cocucci, Andrea Aristides. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Machado, Isabel. Departamento de Botanica, Laboratario de Biologia Flora; Brasil

Oil-flower species are highly specialized attracting a narrow group of oil-collecting bees in contrast to nectar-flower species visited by a wide diversity of pollinators. The vast majority of the oil species lack nectar as a pollinator reward; this suggests that the ancestors of plants with oil flowers had either nectar-less flowers or faced strong selection against the production of nectar once oil secretion evolved. Monttea aphylla is one of the few species that simultaneously offers oil and nectar in the same flower to pollinators. In particular, we studied phenotypic selection in 16 populations in the Monte desert of Argentina that spanned the entire geographical range of the species. In each population, we determined the relationship between plant pollination success and floral rewards. Positive directional selection differentials were detected in three of the populations. One northern population favoured selection on oil production, two central or southern populations favoured selection on nectar production. Directional selection gradients were consistent with the above results and correlational selection was significant for one northern population where pollination success was favoured by an increased selection on oil and a decreased selection on nectar. Geographic variation in phenotypic selection models showed latitudinal increase in directional selection on nectar. Geographic variation in visitation frequencies of the specialist oil-collecting bee and relative abundance of other floral sources were related to an increase in directional selection on nectar. Thus, evolution of rewards appears to respond to a geographic mosaic where either oil or nectar are favoured in different contexts of ecologically specialised oil collecting bees. Although phenotypic selection was detectable in few and was absent in most populations, the general pattern was consistent with current geographic differentiation in reward amounts. Fil: Ferreiro, Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Baranzelli, Matias Cristian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Sersic, Alicia Noemi. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Cocucci, Andrea Aristides. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina

Visitation rates and assemblage composition of pollinators have often been related to environmental, ecological and phenotypic variables. However, the interaction between flowers and pollinators has not been evaluated in a biomechanical context. Floral rewards in keel flowers (Fabaceae, Faboideae) are concealed behind four joined petals, the keel-wing unit, and are accessible only if pollinators open this unit by exerting force on it. Force needed to open the flower is expected to affect the interaction with pollinators because pollinators must invest time and energy to open the keels. Consequently, plants with stiff flowers should be expected to experience diminished visitation frequency, particularly by weak visitors. To test this expectation of diminished visitation rates and of assemblage composition biased by pollinator strength, we measured the force needed to open the keel flowers of five co-occurring legume species and, using a canonical correspondence analysis (CCA), we tested their association with pollinator visitation rates and assemblage composition. We additionally included a size flag variable in CCA to test the effect of attractiveness on pollinator visits. There was no association between flower stiffness and visitation frequency. According to the CCA, pollinator assemblage compositions were associated with the force needed to open the keel and not flag size. As a general pattern, weak flowers are pollinated by an uneven assemblage of weak bees while the stiffest flowers are pollinated by an even assemblage of large and strong bees. These results supports the idea that force has an effect in controlling pollinator assemblage composition.

Colors are important vehicles for social signals in many taxa. In Squamata, previous studies have linked color characteristics and chromatic diversity to sexual selection and, particularly, species showing male-biased body size dimorphism also showed male-biased dichromatism and color diversity. Sexual dichromatism may occur in body regions used for conspecific communication and it may be expressed at wavelengths, such as ultraviolet, easily perceivable by conspecifics. We tested this prediction in a social lizard model, Tropidurus spinulosus, using spectrophotometry and visual modelling which enable colors to be interpreted as the individuals of the same taxon see them. Our results indicate that sexual dichromatism occurs in the ventral regions and the flanks, which are the body regions involved in sexual displays. Males show greater color diversity, having larger color volumes and more contrasting colors. These findings reinforce the idea that sexual selection towards males is coupled with the evolution of male-biased, diverse, coloration which could act as a signal in social reproductive contexts. Fil: Rossi, N.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; Argentina Fil: Benitez-Vieyra, Santiago Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Cocucci, Andrea Aristides. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Chiaraviglio, Margarita. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; Argentina Fil: Cardozo, G.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; Argentina

Despite Stebbins’ principle of the most efficient pollinator being proposed decades ago, the most important pollinators are still mainly identified using the frequency of visits to flowers. This shortcoming results in a gap between the characterization of the flower visitors of a plant species and a reliable estimation of the plant fitness consequences of the mutualistic interaction. The performance of a mutualistic visitor depends on its abundance, behaviour, effectiveness (pollen removal and deposition per unit time) and efficiency (seed set per unit time) conditioned by the temporal matching between pollinator activity and temporal patterns of maturation of the sexual functions of flowers. Although there have been recent attempts to provide a conceptual and methodological framework to characterize pollinators’ performance, few have combined all key elements of visitors and plants to provide an accurate estimation of pollinators’ performance under natural conditions. Fil: Baranzelli, Matias Cristian. Universidad Nacional Autónoma de México; México. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Benitez-Vieyra, Santiago Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Glinos, Evangelina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Trenchi, Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Córdoba, Silvina Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Camina, Julia Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Ashworth, Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Sersic, Alicia Noemi. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Cocucci, Andrea Aristides. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Fornoni, Juan Enrique. Universidad Nacional Autónoma de México; México

Floral scents can act as important contributing factors to plant reproductive isolation mediated by pollinators. Plants may utilize fetid floral odors that specifically lure saprophilous flies seeking high protein content substrates, such as dung or carrion, to reach sexual maturity or as food sources for their larvae. In this work, we used baits with fetid volatile organic compounds (VOCs) that are produced during the decay of animal protein substrates (oligosulfides and a fermented bone-meal blend) to evaluate the role that olfactory signals may have played in the shift to saprophilous fly pollination in species of the nightshade genus Jaborosa Juss. Traps with the fetid baits attracted the same assemblage of saprophilous fly species that were recorded pollinating the flowers in different populations of the Andean-distributed species J. laciniata, whereas no flies were attracted to the control traps using mineral oil. Furthermore, the addition of oligosulfides to flowers of J. integrifolia, a lowland distributed species pollinated by nocturnal hawkmoths, resulted in the nearly immediate attraction of saprophilous flies (mainly Calliphoridae) to the flowers. These results provide evidence that the emission of fetid floral VOCs is sufficient to attract flies to flowers irrespective of other flower features and geographic region. This suggests that the evolutionary shift to saprophilous fly pollination in the genus Jaborosa could have been initiated with novel floral visitors attracted by the emission of fetid VOCs and then followed by major changes in other flower traits such as corolla color and morphology to optimize pollen export and placement. Fil: Moré, Marcela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina. Universidad Nacional de Córdoba; Argentina Fil: Mulieri, Pablo Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; Argentina Fil: Battan Horenstein, Moira. Universidad Nacional de Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; Argentina Fil: Cocucci, Andrea Aristides. Universidad Nacional de Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Raguso, Robert A.. Cornell University; Estados Unidos

Made available in DSpace on 2019-10-06T16:57:32Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-01-23 British Ecological Society Consejo Nacional de Investigaciones Científicas y Técnicas Background and Aims: Large clades of angiosperms are often characterized by diverse interactions with pollinators, but how these pollination systems are structured phylogenetically and biogeographically is still uncertain for most families. Apocynaceae is a clade of >5300 species with a worldwide distribution. A database representing >10 % of species in the family was used to explore the diversity of pollinators and evolutionary shifts in pollination systems across major clades and regions. Methods: The database was compiled from published and unpublished reports. Plants were categorized into broad pollination systems and then subdivided to include bimodal systems. These were mapped against the five major divisions of the family, and against the smaller clades. Finally, pollination systems were mapped onto a phylogenetic reconstruction that included those species for which sequence data are available, and transition rates between pollination systems were calculated. Key Results: Most Apocynaceae are insect pollinated with few records of bird pollination. Almost three-quarters of species are pollinated by a single higher taxon (e.g. flies or moths); 7 % have bimodal pollination systems, whilst the remaining approx. 20 % are insect generalists. The less phenotypically specialized flowers of the Rauvolfioids are pollinated by a more restricted set of pollinators than are more complex flowers within the Apocynoids + Periplocoideae + Secamonoideae + Asclepiadoideae (APSA) clade. Certain combinations of bimodal pollination systems are more common than others. Some pollination systems are missing from particular regions, whilst others are over-represented. Conclusions: Within Apocynaceae, interactions with pollinators are highly structured both phylogenetically and biogeographically. Variation in transition rates between pollination systems suggest constraints on their evolution, whereas regional differences point to environmental effects such as filtering of certain pollinators from habitats. This is the most extensive analysis of its type so far attempted and gives important insights into the diversity and evolution of pollination systems in large clades. Faculty of Arts Science and Technology University of Northampton, Newton Building, Avenue Campus Lehrstuhl für Pflanzensystematik Universität Bayreuth Department of Systematic and Evolutionary Botany University of Zurich, Zollikerstrasse 107 Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM) Curso de Licenciatura em Educação do Campo - LEC Campus JK - Diamantina School of Life Sciences University of KwaZulu-Natal, Private Bag X01 Instituto de Botánica del Nordeste UNNE-CONICET Department of Plant Biology Ecology and Evolution, 301 Physical Sciences Laboratorio de Plantas Vasculares Departamento de Biología Comparada Facultad de Ciencias UNAM Laboratório de Ecologia da Polinização e Interações - LEPI Departamento de Botânica Instituto de Biociências Universidade Estadual Paulista 'Júlio de Mesquita Filho'- Unesp Saint Louis University Department of Biology Biology Extension Building, 1008 S. Spring Ave. Mehmet Akif Ersoy Mah. 269. Cad. Urankent Prestij Konutlarý Department of Biological Sciences University of Cape Town, P/Bag X3 Ecosystem Management Group ETH Zurich EDB UMR 5174 Université de Toulouse UPS, 118 route de Narbonne Laboratorio de Ecología Evolutiva - Biología Floral IMBIV (UNC-CONICET) Departamento de Botânica Museu Nacional Universidade Federal do Rio de Janeiro Quinta da Boa Vista Department of Plant Sciences Faculty of Natural and Agricultural Sciences University of the Free State, PO Box 339 Laboratório de Ciências Ambientais Centro de Biociências e Biotecnologia Universidade Estadual do Norte Fluminense Darcy Ribeiro Departamento de Botânica - CB Laboratório de Biologia Floral e Reprodutiva - POLINIZAR Universidade Federal de Pernambuco Universidade Federal de São Carlos - UFSCar Centro de Ciências Agrárias Depto. Ciências da Natureza Matemática e Educação, Rod. Anhanguera Km 174 Jardim Botânico do Rio de Janeiro, Rua Pacheco Leão 915 Facultad de Ciencias Exactas Fisicas y Naturales Universidad Nacional de Córdoba (UNC) IMBIV (CONICET-UNC) Herbarium - Royal Botanic Gardens Laboratorio de Investigaciones Botánicas (LABIBO) Facultad de Ciencias Naturales Universidad Nacional de Salta-CONICET, Av. Bolivia 5150 Department of Biosciences University of Salzburg Biology Department Franklin and Marshall College Natural History Museum Georgia College, 231 W. Hancock Street Centre for Ecology and Conservation University of Exeter Penryn Campus Department of Biology Willamette University Department of Botany Faculty of Science Chulalongkorn University, Phayathai Road Department of Biodiversity Earth and Environmental Sciences Academy of Natural Sciences Drexel University Center for Ecological Research Kyoto University, Hirano 2-509-3 Universidade Estadual Paulista UNESP Instituto de Biociências Departamento de Botânica Laboratório de Fenologia Tanzania Wildlife Research Institute (TAWIRI), PO Box 661 School of Biological Sciences Royal Holloway University of London Graduate School of Arts and Sciences University of Tokyo, 3-8-1 Komaba Universidade do Estado da Bahia, Campus IX. Rodovia BR 242, km 4, s/n. Flamengo Tropical Biology Association David Attenborough Building, Pembroke Street Instituto de Biologia - UFU, Campus Umuarama Bloco 2D Department of Botany Rhodes University, PO Box 94 Biospheres Eshwari, 52/403, Nanasaheb Peshva Marg, Near Ramna Ganpati Department of Evolution Ecology and Organismal Biology University of California Riverside, 900 University Avenue Departamento de Biologia Universidade Estadual de Feira de Santana, Av. Universitária s/n, Novo Horizonte Key Laboratory for Plant Diversity and Biogeography of East Asia Kunming Institute of Botany Chinese Academy of Sciences, 132 Lanhei Road Laboratorio de Ecología UBIPRO FES-Iztacala Universidad Nacional Autónoma de México Tlalnepantla de Baz Escuela de Ciencias Biológicas Universidad Pedagógica y Tecnológica de Colombia Departamento de Biologia Vegetal Instituto de Biologia Universidade Estadual de Campinas, Caixa Postal 6109 Department of Plant Sciences Natural and Agricultural Sciences University of the Free State, Qwaqwa campus, Kestell Road Penn State University, 542 ASI Building Department of Chemistry and Bioscience Aalborg University, Fredrik Bajers Vej 7H Graduate School of Human Development and Environment Kobe University, 3-11 Tsurukabuto Departamento de Biologia Vegetal Universidade Federal de VIçosa (UFV) Museo Botánico Córdoba y Cátedra de Morfologia Vegetal (IMBIVUNC-CONICET) Graduate School of Technology Industrial and Social Science Tokushima University, 2-1 Minamijyosanjima Centro Acadêmico de Vitória Universidade Federal de Pernambuco Departamento de Educação Universidade Federal da Paraiba Departamento de Engenharia e Meio Ambiente Universidade Federal da Paraiba Laboratório de Ecologia da Polinização e Interações - LEPI Departamento de Botânica Instituto de Biociências Universidade Estadual Paulista 'Júlio de Mesquita Filho'- Unesp Universidade Estadual Paulista UNESP Instituto de Biociências Departamento de Botânica Laboratório de Fenologia

Many angiosperm lineages present transitions from bee to hummingbird pollination. The flower design in most of these lineages includes either corolla tubes or nectar spurs, structures that commonly experienced an elongation with the acquisition of hummingbird pollination. It is proposed that this increases the fit between the bird head and flower structures, and isolates or partially blocks bees from the interaction. But can this transition occur if the ancestral flower design lacks tubes or spurs? Here we focus on the transition from bee to hummingbird pollination in the Loasaceae subfamily Loasoideae. Loasoideae flowers have radial corollas with separated petals; therefore, they do not display corolla tubes nor nectar spurs. These flowers also present a whorl of nectar scales and staminodes, unique to the subfamily, which is involved in flower–pollinator fit and in nectar harvesting. To explore flower shape adaptation to hummingbird pollination, we tested for correspondence between pollinators and flower shape in Loasoideae. In order to achieve this, we first compared the evolutionary history of flower phenotype and pollination mode, and then used stochastic character mapping and geometric-morphometric variables in a comparison of alternative evolutionary models. The results of our study suggest that the transition from bee to bird pollination was accompanied by changes in the shape of the staminodial complex, along with the evolution of relatively closed corollas. Moreover, while bird pollination seems to be the end point in the evolution of pollination syndromes in many angiosperm lineages, rodent pollinated flowers probably evolved from ancestral bird pollinated flowers in Loasoideae. Our findings suggest that the evolution of bird pollinated flowers from ancestral bee pollinated flowers does not require the presence of corolla tubes or spurs, and can take place as long as the flower design includes structures participating in flower–pollinator fit. Fil: Strelin, Marina Micaela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Benitez-Vieyra, Santiago Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Ackermann, Markus. Universitat KoblenzLandau; Alemania Fil: Cocucci, Andrea Aristides. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina

The coevolutionary process among free-living mutualists with extremely long matching traits may favor the formation of mutualistic interaction networks through coevolutionary escalation, complementarity and convergence. These networks may be geographically structured; the links among the species of a local network are shaped by the biotic composition of the community, thus creating selection mosaics at broader geographical scales. Therefore, to fully understand a coevolutionary process, it is crucial to visualize the geographical structure of the interaction network across the landscape. In this study we focused on the poorly known interaction system between Ensifera ensifera and its guild of long-flowered plant species. We combined occurrence data and environmental variables to predict E. ensifera distribution, in addition to range polygons available for plant species in order to evaluate the geographical variation in bill length and plant species richness. A positive relationship between bill length and plant species richness within the E. ensifera range suggests a geographical structuring of the interaction networks. At mid-latitude locations of E. ensifera range, where hummingbirds attained the longest bills, richness of long-flowered plant species was higher than at low latitude locations. These locations likely represent coevolutionary vortices where long-lasting reciprocal selection probably drove the evolution of long traits, consequently drawing new plant species into the coevolutionary network. Conversely, areas where the sword-billed hummingbird was absent or had shorter bills probably represent coevolutionary coldspots. Our results provide a first insight into this phenotypically specialized plant-pollinator network across the landscape and show candidate areas to test the predictions of the coevolutionary hypothesis, such as reciprocal selection. Fil: Soteras, María Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Moré, Marcela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Ibañez, Ana Clara. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Iglesias, María del Rosario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Cocucci, Andrea Aristides. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina

Geologic events promoting the aridization of southern South America contributed to lineage divergences and species differentiation through geographic (allopatric divergence) and biotic and abiotic factors (ecological divergence). For the genus Anarthrophyllum, which is distributed in arid and semi-arid regions of Patagonia, we assessed how these factors affected species diversification and reconstructed its possible biogeographic history in South American arid environments. Sequences were obtained from two molecular markers: the ITS nuclear region and the trnS-trnG plastid region. Using Parsimony, Maximum likelihood and Bayesian inference individual gene trees were reconstructed, and a species tree was obtained using multi-species coalescent analysis. Divergence times among species were estimated using secondary calibrations. Flexible Bayesian models and stochastic character mapping were used to elucidate ancestral geographic distributions and the evolution of the floral and vegetative phenotypes in the genus. Gene trees and species tree analyses strongly support Anarthrophyllum as monophyletic; all analyses consistently retrieved three well-supported main clades: High Andean Clade, Patagonian Clade 1, and Patagonian Clade 2. Main diversification events occurred concomitant with the Andean uplift and steppe aridization; the Andean mountain range possibly acted as a species barrier for the High Andean Clade. Vegetative traits showed adaptations to harsh climates in some clades, while pollinator-related floral features were associated with independent diversification in bee- and bird-pollinated clades within both Patagonian Clades. In conclusion, evolutionary and biogeographic history of Anarthrophyllum resulted from the action of ecological, historical, and geographic factors that acted either alternatively or simultaneously. Fil: Achimón, Fernanda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Johnson, Leigh. University Brigham Young; Estados Unidos Fil: Cocucci, Andrea Aristides. Universidad Nacional de Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Sersic, Alicia Noemi. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina. Universidad Nacional de Córdoba; Argentina Fil: Baranzelli, Matias Cristian. Universidad Nacional de Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina

The astounding variety of angiosperm flower morphologies has evolved in response to many selective forces. Flower development is highly coordinated and involves developmental associations between size and shape, ontogenetic allometry, which in turn affect the morphology of mature flowers. Although ontogenetic allometries can act as a developmental constraint and may influence adaptive evolution, allometries can evolve themselves and may change rapidly in response to selection. We explored the evolution of ontogenetic allometry in the flowers of 11 species of Loasoideae. Seven species belong to Caiophora, which radiated recently in the central Andes, and contains species that are pollinated by bees, hummingbirds, and small rodents. According to a previous study, the diversification of Caiophora involved departures from simple allometric scaling, but the changes to allometry that enabled flower diversification have not been explored yet. We characterized the ontogenetic allometry of each species with the methods of geometric morphometrics. We studied the evolution of allometries by constructing allometric spaces, in which the allometry of each species is represented by a point and the arrangement of points indicates the relations among allometric trajectories. To examine the history of changes of ontogenetic allometries, we projected the phylogeny into the allometric spaces. Inspection of allometric spaces suggests that ontogenetic variation is limited to a few dominant features. The allometries of the two main functional flower parts under study differ in their evolutionary labilities, and patterns of variation reflect pollination systems, differences in structural organization, and abiotic environmental factors. Fil: Strelin, Marina Micaela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina Fil: Benitez Vieyra, Santiago Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Fornoni, Juan. Universidad Nacional Autónoma de México; México. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina Fil: Klingenberg, Christian Peter. University of Manchester; Reino Unido Fil: Cocucci, Andrea Aristides. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina

Fil: More, Marcela. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Cordoba. Instituto Multidisciplinario de Biologia Vegetal (p); Argentina

Fil: Ferreiro, Gabriela. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Cordoba. Instituto Multidisciplinario de Biologia Vegetal. Universidad Nacional de Cordoba. Facultad de Ciencias Exactas Fisicas y Naturales. Instituto Multidisciplinario de Biologia Vegetal; Argentina

The multidisciplinary field of pollination biology was enriched enormously by the contributions of Stefan Vogel (1925–2015). Vogel revived and expanded the pollination syndrome concept and recognized the importance of shifts between pollination modes for angiosperm diversification. He made a number of key discoveries, including perfume and oil reward systems in flowers and pollination of these flowers by highly specialized bees. He also contributed greatly to our understanding of floral mimicry, floral integration, and floral adaptations for bat pollination. Many of his insights were obtained through his field-based research in the tropics and his close ties to faculty and students at various universities in South America. Vogel´s work continues to be the inspiration for new scientific endeavours and this special issue of Flora about “Patterns and mechanisms in plant-pollinator interactions” contains a collection of 22 research papers that serve as a tribute to his legacy. The papers cover a wide range of topics and taxa, but can be broadly grouped into the themes of plant-pollinator interactions, functional morphology, floral rewards, floral signals and pollination syndromes, all of which also featured prominently in Vogel´s own work. Fil: Cocucci, Andrea Aristides. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Johnson, Steven D.. University of KwaZulu-Natal; Sudáfrica

The endemic shrub Anarthrophyllum desideratum appears to be the only ornithophilous plant offering nectar as reward in the extensive Patagonian steppe. The identity of its floral visitor assemblage and to what extent this species depends on bird pollination for sexual reproduction is yet unknown. A. desideratum?s vast distribution includes climatic gradients, which may promote geographical shifts in its floral visitors. The aims of this study were to determine the species dependence on pollinators to set fruits, to identify its floral visitor assemblages, to document possible geographical and environmental variation of these assemblages across the species range and to assess their temporal constancy. We conducted different pollination treatments in several populations to assess the species breeding system. Floral visitors were identified in 18 populations distributed along the entire species range and their visitation frequencies were quantified over three flowering periods. We found that the species is self-compatible and that floral visitors do not contribute to fruit set in two marginal populations. Fruit set of open pollinated plants significantly differed among populations, which suggests that the species dependence on pollinators varies among sites. Eight species of non-exclusively nectarivorous birds, mostly passerine, were observed visiting flowers arranged in different assemblages across the species range. Population differences in the proportion of visits by the two most abundant bird species remained constant over time. Geographical differences of bird assemblages were not spatially structured and were weakly associated with climate of the flowering period, suggesting that climatic gradients would not be important as drivers of the geographical variation in A. desideratum? floral visitors. Our results indicate that non-exclusively nectarivorous birds visit flowers of A. desideratum, revealing for first time the facultative nectarivory behaviour of these bird species in the Patagonian steppe. The potential role of such bird visitors as pollinators of A. desideratum appears to vary geographically. El arbusto endémico Anarthrophyllum desideratum parece ser la única planta ornitófila que ofrece néctar como recompensa en la extensa estepa patagónica. Aún se desconoce la identidad de su ensamble de visitantes florales y en qué medida esta especie depende de la polinización por aves para la reproducción sexual. La distribución amplia de A. desideratum incluye gradientes climáticos que pueden promover cambios geográficos en sus visitantes florales. Los objetivos de este estudio fueron determinar la dependencia de esta especie de los polinizadores para la producción de frutos, identificar sus ensambles de visitantes florales, documentar posibles variaciones geográficas y ambientales de estos ensambles a lo largo del rango de distribución de la especie, y evaluar su constancia temporal. Realizamos diferentes tratamientos de polinización en varias poblaciones para evaluar el sistema reproductivo de la especie. Para 18 poblaciones a lo largo de todo el rango de distribución de la especie identificamos los visitantes florales y cuantificamos sus frecuencias de visitas durante tres períodos de floración. Encontramos que la especie es auto-compatible y que los visitantes florales no contribuyen a la formación de frutos en dos poblaciones marginales. La producción de frutos de las plantas bajo polinización abierta difirió significativamente entre poblaciones, lo cual sugiere que la dependencia de la especie de polinizadores varía entre sitios. Ocho especies de aves no exclusivamente nectarívoras, en su mayoría paseriformes, se observaron visitando las flores dispuestas en diferentes ensambles a lo largo del rango de distribución de la especie. Las diferencias entre poblaciones en la proporción de visitas de las dos especies de aves más abundantes se mantuvieron constantes en el tiempo. Las diferencias geográficas en los ensambles de aves no estuvieron espacialmente estructuradas y se asociaron de forma débil con el clima del período de floración, lo que sugiere que los gradientes climáticos no serían importantes como factores determinantes de la variación geográfica en los visitantes florales de A. desideratum. Nuestros resultados indican que aves no exclusivamente nectarívoras visitan las flores de A. desideratum. Esto revela por primera vez el comportamiento nectarívoro facultativo de estas especies de aves en la estepa patagónica. El papel potencial de estas aves visitantes como polinizadores de A. desideratum parece variar geográficamente. Fil: Paiaro, Valeria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Cocucci, Andrea Aristides. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Oliva, Gabriel Esteban. Universidad Nacional de la Patagonia Austral; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Patagonia Sur; Argentina Fil: Sersic, Alicia Noemi. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina

Proboscis length has been proposed as a key dimension of plant pollination niches, but this niche space has not previously been explored at regional and global scales for any pollination system. Hawkmoths are ideal organisms for exploring pollinator niches as they are important pollinators in most of the biodiverse regions of the earth and vary greatly in proboscis length, with some species having the longest proboscides of all insects. Using data sets for nine biogeographical regions spanning the Old and New World, we ask whether it is possible to identify distinct hawkmoth pollination niches based on the frequency distribution of proboscis length, and whether these niches are reflected in the depths of flowers that are pollinated by hawkmoths. We also investigate the levels of specialization in hawkmoth pollination systems at the regional and community level using data from interaction network studies. We found that most regional hawkmoth assemblages have bimodal or multimodal distributions of proboscis length and that these are matched by similar distributions of floral tube lengths. Hawkmoths, particularly those with longer proboscides, are polyphagous and at the network level show foraging specialization equivalent to or less than that of bees and hummingbirds. In the case of plants, shorter-tubed flowers are usually visited by numerous hawkmoth species, while those that are longer-tubed tend to exclude shorter-proboscid hawkmoths and thus become ecologically specialized on longer-proboscid hawkmoth species. Longer-tubed flowers tend to have greater nectar rewards, and this promotes short-term constancy by long-proboscid hawkmoths. Our results show that pollinator proboscis length is a key niche axis for plants and can account for the patterns of evolution in functional traits such as floral tube length and nectar volume. We also highlight a paradoxical trend for nectar resource niche breadth to increase according to proboscis length of pollinators, while pollinator niche breadth decreases according to the tube length of flowers. Fil: Johnson, Steven D.. University of KwaZulu Natal; Sudáfrica Fil: More, Marcela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Amorim, Felipe W.. Universidade Estadual Paulista Julio de Mesquita Filho; Brasil Fil: Haber, William A.. Monteverde; Costa Rica Fil: Frankie, Gordon W.. University of California Berkeley; Estados Unidos Fil: Stanley, Dara A.. University of KwaZulu Natal; Sudáfrica Fil: Cocucci, Andrea Aristides. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Raguso, Robert A.. Cornell University; Estados Unidos

More, M.; S. Benitez-Vieyra, A. N. Sersic & A. A. Cocucci. 2014. Pollen deposition patterns onto the pollinators' body in sphingophilous communities of subtropical Argentina. Darwiniana, nueva serie 2(1): 174-196. Plant species that coexist and share pollinators may experience inter-specific competition for pollina- tor service or interference of improper pollen. To avoid the latter, plant species may use different areas of the pollinatorsbody to deposit their pollen, either by different floral architectures or by different floral lengths. We evaluate here the existence of this pattern of differential use of body areas of pollinators in 33 sphingophilous communities of subtropical Argentina. We use null models to evaluate if the plants deposit the pollen overdispersed relative to what would be expected by chance either in different body parts or at different heights in the proboscis of hawkmoth pollinators. We found that 42 native plants species are pollinated by hawkmoths in subtropical Argentina. We observed a significant and positive correlation between the operative length -i.e. the distance between anthers and stigma from nectar- of the flowers and the mean length of the proboscis of hawkmoth pollinators. However, both the average di- versity of pollen deposition sites and the average difference of operative length between sphingophilous plant species present in the same community were not significantly different than expected under a null model. When analyzing the results in individual communities, nine communities showed a diversity of pollen deposition sites significantly higher than expected by chance and two communities showed a di- fference in the operative length greater than expected by chance. These results suggest that other factors such as the degree of generalization in pollination, phenology and / or the use of distinctive floral signals may be avoiding competition for pollinators between coexisting plants species.

Background and Aims: The underlying evolutionary processes of pollinator-driven floral diversification are still poorly understood. According to Grant-Stebbins model speciation begins with adaptive local differentiation in response to spatial divergence in pollinators. Despite this crucial process links the micro- and macroevolution of floral adaptation, has received relatively poor attention. We studied geographical phenotypic variation of the Patagonian Calceolaria polyrhiza and its pollinators, two oil-collecting bee species that differ in body size and geographical distribution. Methods: We examined geographical pattern of phenotypic variation and its relationship with pollinators and abiotic factors. Six floral and seven vegetative traits were measured in 46 populations distributed across the entire species range. We selected 24 sites and retrieved their climatic and edaphic parameters; we captured 2-16 bees/site of the most frequent pollinator species and measured a critical flower-bee fitting trait involved in effective pollination. Geographical patterns of phenotypic variation and environmental variation were examined using uni- and multivariate analyses. Mantel permutation test was used to explore decoupled geographic variation between corolla area and fit-related floral traits. Key Results: Body length of pollinators and floral fit-related traits were strongly correlated with one another. Geographic variation of mechanical-fit related traits is decoupled from variation in corolla size. This latter floral trait has a geographical pattern consistent with that of vegetative traits and is mainly affected by climatic gradients. Conclusions: In this system pollinators play a key role in shaping floral phenotype at a geographical scale, promoting the differentiation of two floral ecotypes. The relationship between floral fit-related trait and bee length remained significant even in models that included various environmental variables and an allometric predictor (corolla area) one. The abiotic environment also has an important role, mainly affecting floral size. Decoupled geographical variation between fit-related traits and floral size is suggested to represent a strategy to maintain plant-pollinator phenotypic matching in this environmentally heterogeneous area. Fil: Cosacov Martinez, Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Cocucci, Andrea Aristides. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Sersic, Alicia Noemi. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina

Premise of research. Brood-site deceptive flowers use dishonest signals?especially floral odors that mimic oviposition substrates?to attract and deceive saprophilous insects to pollinate them. In this work, we recorded the pollinators of the sapromyiophilous species Jaborosa rotacea (Solanaceae) endemic to southern South America. Then, we characterized the floral volatiles of this species, and finally, we carried out field experiments to decouple the effects of scent and color as attractants for saprophilous flies. Methodology. We made direct observations of pollinators in a natural population of J. rotacea.We characterized floral volatiles by means of gas chromatography?mass spectrometry. Subsequently, we used a mixture of 2 oligosulfides (dimethyl disulfide and dimethyl trisulfide), which our analyses revealed were the main constituents of the floral scent ofJ. rotacea, as baits to determine the attractiveness of this olfactory signal to flies in a geographical region whereJ. rotaceais not present. Finally, we used the same foul-scented baits in arrays of artificial flowers resembling those of J. rotacea to assess the dual importance of olfactory and visual cues in fly attraction. Pivotal results. Pollination of J. rotaceaoccurs when saprophilous flies belonging to the families Calliphoridae, Muscidae, and Sarcophagidae?with similar body dimensions to the anther-stigma distance in these flowers?acquire and deposit pollen in the flowers in a nototribic mode. Our chemical analyses revealed that J. rotacea floral scent is chemically simple and features 2 oligosulfide compounds (dimethyl disulfide and dimethyl trisulfide) commonly found in carrion-mimicking flowers. We found that saprophilous flies belonging to the same families that we recorded as pollinators of J. rotaceain its native South American habitat were attracted to foul-scented baits in temperate North America. The flies? visitation frequencies (recorded as approaches and landings on the artificial flowers) depended significantly on the presence of the foul-scented baits. Conclusions. These results support the hypothesis that oligosulfides are universally effective signals by which deceptive flowers may effect pollen dispersal by attracting flies that use carrion or carnivore feces as brood sites. Keywords:brood-site deceptive flowers, Diptera, Jaborosa rotacea, oligosulfides, scent mimicry, Solanaceae. Fil: More, Marcela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal (p); Argentina; Fil: Cocucci, Andrea Aristides. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal (p); Argentina; Fil: Raguso, Robert A.. Cornell University; Estados Unidos de América

Phenotypic diversification of flowers is frequently attributed to selection by different functional groups of pollinators. During optimization of floral phenotype, developmental robustness to genetic and non-genetic perturbations is expected to limit the phenotypic space available for future evolutionary changes. Although adaptive divergence can occur without altering the basic developmental programme of the flower (ontogenetic scaling hypothesis), the rarity of reversion to ancestral states following adaptive radiations of pollination syndromes suggests that changes in the ancestral developmental programme of the flower are common during such evolutionary transitions. Evidence suggests that flower diversification into different pollination syndromes in the Loasoideae genus Caiophora took place during a recent adaptive radiation in the central Andes. This involved transitions from bee to hummingbird and small rodent pollination. The aim of this work was to examine if the adaptive radiation of pollination syndromes in Caiophora occurred through ontogenetic scaling or involved a departure from the ontogenetic pattern basal to this genus. Fil: Strelin, Marina Micaela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Benitez-Vieyra, Santiago Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Fornoni, Juan. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina. Universidad Nacional Autónoma de México; México Fil: Klingenberg, Christian Peter. University of Manchester; Reino Unido Fil: Cocucci, Andrea Aristides. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina

Interactions with pollinators are thought to play a significant role in determining whether plant species become invasive, and ecologically generalised species are predicted to be more likely to invade than more specialised species. Using published and unpublished data we assessed the floral biology and pollination ecology of the South American native Nicotiana glauca (Solanaceae) which has become a significant invasive of semi-arid parts of the world. In regions where specialised bird pollinators are available, for example hummingbirds in California and sunbirds in South Africa and Israel, N. glauca interacts with these local pollinators and sets seed by both out-crossing and selfing. In areas where there are no such birds, such as the Canary Islands and Greece, abundant viable seed is set by selfing, facilitated by the shorter stigma-anther distance compared to plants in native populations. Surprisingly, in these areas without pollinating birds, the considerable nectar resources are only rarely exploited by other flower visitors such as bees or butterflies, either legitimately or by nectar robbing. We conclude that Nicotiana glauca is a successful invasive species outside of its native range, despite its functionally specialised hummingbird pollination system, because it has evolved to become more frequently self pollinating in areas where it is introduced. Its invasion success is not predictable from what is known of its interactions with pollinators in its home range.

Aim In order to assess the impact of precipitation changes during Pleistoceneglaciations on plant species of the Patagonian steppe, a phylogeographical studyof the endemic shrub Anarthrophyllum desideratum was performed.Location Southern Patagonia: Argentina and Chile.Methods Chloroplast intergenic spacers trnS–trnG and rpoB–trnC weresequenced for 264 individuals from 33 localities spanning the entire distribu-tion of A. desideratum. Phylogenetic (statistical parsimony, maximum likeli-hood and Bayesian inference) and population genetic analyses (spatial analysesof molecular variance, mismatch distributions, neutrality tests and Bayesianskyline plot) were performed. Divergence time estimates using a calibratedmolecular clock were also conducted. Niche modelling was used to reconstructthe palaeodistribution to validate phylogeographical patterns.Results Thirty haplotypes were identified that clustered into two main lin-eages, revealing a significant latitudinal phylogeographical break north andsouth of the Deseado River (c.47° S). Infra-specific diversification began in thelate Miocene, with northern and southern lineages separating c. 3 Ma, after theeastern Patagonian lowlands started to become increasingly arid. Three areas ofhigh molecular diversity were identified: one in southern and two in northernPatagonia where niche modelling indicates that the species may have survivedduring the Last Glacial Maximum. These putative refugia received more mois-ture than much of the steppe during glaciation-associated aridization. Thesouth-western refugium is the more likely source for eastward range expansionduring post-glacial humidification.Main conclusions Anarthrophyllum desideratum responded differently to his-torical processes north and south of the Deseado River. In the north this spe-cies survived in situ in fragmented populations, whereas in the south itsurvived in localized refugia that presumably avoided extreme aridization, andfrom which it expanded eastwards. For southern Patagonia, our results supporta new historical scenario affected more by precipitation regimes than by tem-perature changes associated with glacial cycles. This hypothesis should be con-sidered in future plant phylogeographical studies from the Patagonian steppe.KeywordsAridization, cold–warm hypothesis, ecological niche modelling, Fabaceae, his-torical water balance, in situ survival, plant phylogeography, Pleistocene glaci-ations, refugia, westerlies.168

Over the years, selection can vary in intensity and direction. Selection on traits related to the mechanical fit with pollinators is expected to vary according to changes in pollinator assemblage. Provided that pollinators do not change over time selection on traits related to attraction, such as floral fragrance, is expected to be mainly affected by environmental conditions because its production is resource limited. We examined selection patterns on osmophore area (as a surrogate of odour production), nectary depth and flower number in the orchid Cyclopogon elatus during four consecutive years, and simultaneously recorded variations in weather conditions and differences in pollinator assemblages. We also studied whether the osmophore area was positively related to pollinator attraction and examined its possible trade-off with phenology. We found that patterns of selection on nectary depth did not vary significantly among years. This lack of temporal variation is consistent with the stability of a single bee species as the predominant pollinator. On the contrary, selection on osmophore area varied markedly and was negative during the driest year. Negative selection indicates that although pollinators visited plants with larger osmophore areas more frequently, it did not translate into higher fitness. Plants with larger osmophore areas begin to flower earlier and might be more affected by weather conditions, not directly due to resource availability but indirectly because of the lack of pollinators at the beginning of the flowering season.

Background: In widely distributed species, geographic patterns of phenotypic variation can appear in a clinal (linear or central–marginal) or mosaic fashion in response to environmental factors. Aim: We assessed spatial patterns and possible abiotic drivers of flower and leaf variation in Anarthrophyllum desideratum, an endemic legume found throughout a wide environmental gradient in southern Patagonia. Methods: We measured 10 floral and foliar traits from 26 populations, distributed along the entire range of the species. We examined phenotypic variation within and among populations, geographical patterns, relationships with climatic and edaphic factors and spatial covariation between flowers and leaves, using uni- and multivariate analyses. Results: Most of the studied traits showed higher variability among than within populations. Within-population variability was not associated with population size. Phenotypic differences among populations were structured by geographic distances. Clinal variation patte...

†Background and Aims The extreme complexity of asclepiad flowers (Asclepiadoideae ‐ Apocynaceae) has generated particular interest in the pollination biology of this group of plants especially in the mechanisms involved in the pollination processes. This study compares two South American species, Morrenia odorata and Morrenia brachystephana, with respect to morphology and anatomy of flower structures, dynamic aspects of the pollination mechanism, diversity of visitors and effectiveness of pollinators. †Methods Floral structure was studied with fresh and fixed flowers following classical techniques. The pollination mechanism was studied by visiting fresh flowers in the laboratory with artificial pollinator body parts created with an eyelash. Morphometric and nectar measurements were also taken. Pollen transfer efficiency in the flowers was calculated by recording the frequency of removed and inserted pollinia. Visitor activity was recorded in the field, and floral visitors were captured for subsequent analysis of pollen loads. Finally, pollinator effectiveness was calculated with an index. †Key Results The detailed structure of the flowers revealed a complex system of guide rails and chambers precisely arranged in order to achieve effective pollinaria transport. Morrenia odorata is functionally specialized for wasp pollination, and M. brachystephana for wasp and bee pollination. Pollinators transport chains of pollinaria adhered to their mouthparts. †Conclusions Morrenia odorata and M. brachystephana present differences in the morphology and size of their corona, gynostegium and pollinaria, which explain the differences in details of the functioning of the general pollination mechanism. Pollination is performed by different groups of highly effective pollinators. Morrenia species are specialized for pollination mainly by several species of wasps, a specialized pollination which has been poorly studied. In particular, pompilid wasps are reported as important pollinators in other regions outside South Africa. A putative new function of nectar in asclepiads is presented, as it would be contributing to the pollination mechanism.

Geographic pattern of phenotypic variation can appear in a clinal or a mosaic fashion and can evidence adaptive or non-adaptive variation. To shed light on the mechanisms underlying this variation, we studied the relationships between geographic variation of floral traits and both biotic and abiotic factors of the hummingbird-pollinated plant, Nicotiana glauca, across its natural range. We obtained floral measures of 38 populations from an area about 1600 km long and 1050 km wide and an altitude range from 7 to over 3400 m. We used a MANOVA to detect between-population differentiations in flower traits and a DFA to determine the traits that best discriminate between populations. To test for associations between floral traits and climatic variables we used correlation analysis. We explored any possible distance-based pattern of variation (either geographic or altitudinal) in floral traits or bill length of pollinators using Mantel tests. Finally, we used a multiple regression to analyze simultaneously the effects and relative importance of abiotic predictor variables and bill length on corolla length. We found a high variation in flower traits among populations. Morphometric traits were the ones that best discriminated across populations. There was a clinal pattern of floral phenotypic variation explained by climatic factors. Differences in floral phenotypic distances were structured by altitudinal distances but not by geographic distances. Bill length of the hummingbird pollinators was structured both by altitudinal and geographic distances. Differences in bill length of hummingbird pollinators explained differences in corolla length across populations. Our findings support the assumption of flower evolution at a broad geographic scale. Floral traits seem to be structured not only by altitude but also by climatic factors. Fil: Nattero, Julieta. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto Multidisciplinario de Biología Vegetal (p); Argentina Fil: Sersic, Alicia Noemi. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto Multidisciplinario de Biología Vegetal (p); Argentina Fil: Cocucci, Andrea Aristides. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto Multidisciplinario de Biología Vegetal (p); Argentina

The rate of pollen exchange within and among flowers may depend on pollinator attraction traits such as floral display size and flowering plant density. Variations in these traits may influence pollinator movements, pollen receipt, and seed number. To assess how floral display size and flowering plant density affect parameters of pollinator visitation rate, pollen receipt per flower, seed number per fruit and the between-plant pollinator movements, we studied the self-incompatible plant, Nierembergia linariifolia. Per-flower pollinator visitation rate and bout length increased linearly with increasing floral display size. Pollen receipt per flower increased linearly with increasing flowering plant density. For seed number per fruit, a polynomial model describing an increased seed number per fruit at low density and a decreased seed number per fruit at high density provided a significant fit. Per-flower pollinator visitation rate was not associated with pollen receipt per flower and seed number per fruit. Bees visited plants located near to the center of the population more frequently than plants located at the periphery. Increases in both floral display size and flowering plant density led to an increased chance of a plant being chosen as the center of the pollinator foraging area. These results suggest that even though large floral displays and high flowering plant density are traits that attract more pollinators, they may also reduce potential mate diversity by restricting pollen movement to conspecific mates that are closely located.

Phylogeographical inferences, applied in a comparative framework across multiple species at a regional scale, provide the means for detecting regional and landscape-level patterns of biodiversity, which are important for understanding macroecology and evolution in a geographical mosaic against a backdrop broadly impacted by geological events. Although information on Patagonian phylogeographical patterns has accumulated for both aquatic and terrestrial organisms in recent years, no attempt has been made to compare patterns across major organismal groups. In this review, we compiled studies on the phylogeography of co-distributed plants and terrestrial vertebrates from Patagonia. From each study, we extracted information on levels of genetic diversity, and inferred demographic processes and phylogeographical breaks, as well as on putative refugia, to produce the first summary of emerging phylogeographical patterns for this region. This review reveals some congruent phylogeographical patterns within and among plants and terrestrial vertebrates, and suggests that Pre-Quaternary as well as Quaternary geological events would have been important driving forces in the evolutionary history of Patagonian lineages. Different processes and directional range shifts suggest a mosaic of phylogeographical patterns, far more complex than the several north–south common patterns traditionally proposed. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 103, 475–494. Las inferencias filogeograficas, dentro de un marco comparativo cuando incluyen varias especies a escala regional, permiten detectar patrones de biodiversidad regional y de paisaje (fisonomicos), importantes para entender tanto la macroecologia como el impacto a gran escala de los eventos geologicos. En los ultimos anos, el conocimiento filogeografico de Patagonia se ha acumulado para organismos acuaticos y terrestres, y aunque se han propuesto pocos patrones demograficos o espaciales cualitativamente concordantes, no se ha hecho ningun intento de revisar comparativamente algunos de esos patrones considerando grandes grupos de organismos. En esta revision compilamos el conocimiento publicado sobre la filogeografia de plantas vasculares y vertebrados terrestres de Patagonia con el proposito de comparar niveles de diversidad genetica, procesos demograficos, quiebres filogeograficos y localizacion de posibles refugios, para producir el primer resumen de patrones filogeograficos emergentes para esta region. Esta revision revela algunos patrones filogeograficos congruentes dentro y entre plantas vasculares y vertebrados terrestres, y sugiere que tanto los eventos geologicos Cuaternarios como los pre-Cuaternarios pudieron haber jugado un papel importante en la historia evolutiva de los linajes patagonicos. Diferentes procesos y cambios direccionales en los rangos de distribucion, sugieren un mosaico de patrones filogeograficos mucho mas complejo que los patrones norte-sur tradicionalmente propuestos.

The anatomy of the bizarre style of Canna indica is analyzed functionally and comparatively within Zingiberales, particularly in relation to the presence of two stigma-like areas, one apical and the other lateral and subapical. We asked whether these areas have separate receptive or adhesive functions and whether they are derived from a single stigma that previously had both functions. We expected that the mechanism of pollen transference would be highly effective at the flower level, i.e., that pollen limitation would affect fruit set rather than seed set. Both areas produce a sticky carbohydrate- and mucilage-positive exudate but only the apical one leads to pollen tube growth into the stylar canal. The subapical and lateral area is regarded here as being homologous to the viscidium of Lowiaceae and Marantaceae. High pollen limitation through fruit set is attributable to the low visitation rate of the single long-billed hummingbird pollinator (Heliomaster furcifer) and to pollen loss caused by nectar robbers, while low limitation through seed set suggests that the efficiency of a few visits of pollen-carrying hummingbirds is high. Recordings of the pollination process indicate that the viscidium is touched before the pollen presenter, when hummingbirds are flying out of the flowers.

Most studies on pollinator-mediated selection have been performed in generalized rather than specialized pollination systems. This situation has impeded evaluation of the extent to which selection acts on attraction or specialized key floral traits involved in the plant-pollinator phenotypic interphase. We studied pollinator-mediated selection in four populations of Nierembergia linariifolia, a self-incompatible and oil-secreting plant pollinated exclusively by oil-collecting bees. We evaluated whether floral traits experience variable selection among populations and whether attraction and fit traits are heterogeneously selected across populations. Populations differed in every flower trait and selection was consistently observed for corolla size and flower shape, two traits involved in the first steps of the pollination process. However, we found no selection acting on mechanical-fit traits. The observation that selection occurred upon attraction rather than mechanical-fit traits, suggests that plants are not currently evolving fine-tuned morphological adaptations to local pollinators and that phenotypic matching is not necessarily an expected outcome in this specialized pollination system.

We studied six populations of the hummingbird-pollinated Nicotiana glauca to determine if the marked differences in the degree of floral-pollinator mismatch between populations promote divergences in the pattern of pollinator-mediated phenotypic selection on single traits and on the evolution of complexes of many interacting floral traits. We found evidence that flower phenotype is being shaped by pollinator-mediated phenotypic selection, since corolla length was consistently under contemporary directional or stabilizing selection. Weak directional selection for longer corollas was found in two populations with low flower–pollinator mismatch; much stronger directional selection was detected for shorter corollas in two populations with high flower–pollinator mismatch; finally, the remaining two populations with intermediate flower–pollinator mismatch showed stabilizing selection for corolla length. N. glauca populations differed in every flower character measured but variations in pollinator-mediated selection among populations were only observed for corolla length. Multiple covariation among traits was favoured, as suggested by the predominately functional patterns of integration and selection of complexes of many interacting floral traits. This was consistent with the patterns of correlational selection exhibited by four of the six populations, where corolla length was under significant selection in combination with corolla width, style length or stamen length. Overall floral integration was relatively high in all populations but phenotypic integration patterns were not clearly accounted by the degree of flower–pollinator mismatch or type of phenotypic selection, suggesting that trait covariation at the entire flower level is not explained by the current scenario of pollinator-mediated selection.

We studied gland morphology, anatomy and the chemical composition of the floral fragrance in the sweat bee-pollinated orchid Cyclopogon elatus. This is apparently the first such analysis for any Cyclopogon species, and one of very few studies in which both odour and osmophore are characterised in a nectar-rewarding orchid. Structures responsible for floral scent production were localised with neutral red staining and histochemical assays for lipids and starch. Their morphology and anatomy were studied with scanning electron microscopy and light microscopy thin sections, respectively. Fragrance samples were collected using SPME fibres and analysed with GC-MS. Anatomical evidence suggests that two parallel oval-shaped patches of unicellular trichomes on the abaxial surface of the labellum are osmophores. These are rich in stored lipids, while the parenchyma surrounding the vascular bundles contains starch. Only freshly opened flowers produced odours, while buds and withered flowers lacked scent. The chemical composition of the odour was dominated (>99.8%) by a single compound, trans-4,8-dimethyl-nona-1,3,7-triene (DMNT). Gland anatomy and position on the outside of the perianth are unusual for scent glands in general. The presence of DMNT, a nearly ubiquitous compound in herbivore-induced vegetative emissions and one of the major floral volatiles of Yucca, is not surprising in view of hypotheses on the evolutionary origin of flower scents, suggesting that wound volatiles are utilised as kairomonal attractants by florivores whose activities result in pollination.

Nierembergia (Solanaceae) contains 21 species found primarily in South America, with one species occurring disjunctly in Mexico. Among other features, a pollination system not found elsewhere in the Solanaceae typifies this genus. In most species, nectaries are absent, but oil-producing elaiophores are present on the corolla limb and these attract oil-collecting bees. Molecular phylogenetic hypotheses based on nuclear ITS and chloroplast rpl16 intron data support the monophyly of Nierembergia, which is sister to a clade composed of Bouchetia plus Hunzikeria. The data reconstruct two clades within the genus: one composed primarily of herbaceous species with broad stigmas and the second containing woody species with crescent-shaped stigmas. Morphological homoplasy is frequent among the species of the herbaceous clade, while the woody clade is morphologically cohesive. Chromosome counts are confirmed and karyotype features are given for 13 Nierembergia species (including six varieties) and for Bouchetia anomala, Leptoglossis linifolia, and Petunia axillaris. The two clades are also supported by karyotypic features: one has asymmetrical karyotypes, small chromosomes, and two chromosome pairs with nucleolar organizing regions (NOR) and the other has symmetrical karyotypes, large chromosomes, and only one NOR.

It is well known that habitat fragmentation is likely to negatively affect the reproductive success of a species. Despite this fact, studies on the effects of fragmentation on reproductive success in combination with effects on natural pollination of wind-pollinated tree species are very rare. In this study, we analyzed the relationships between fragment size, components of pollination efficiency, reproductive success and progeny vigour of the highly fragmented populations of the wind-pollinated treeline species Polylepis australis (Rosaceae) in Argentina. We conducted our study in the high mountains of Córdoba, comparing pollination efficiency and reproduction between four fragment sizes. Most of our results indicate that P. australis is currently insensitive to fragmentation. However, our study revealed also a linear increase in leaf area and biomass of 40-day-old seedlings with increasing fragment size. Inbreeding problems through fragmentation as well as decreased habitat quality in small fragments are discussed as possible causes for the impaired progeny vigour. Fil: Seltmann, Peggy. Martin-Luther-University; Alemania Fil: Renison, Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas; Argentina. Martin-Luther-University; Alemania Fil: Cocucci, Andrea Aristides. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Hensen, Isabell. Martin-Luther-University; Alemania Fil: Jung, Klaus. Centre for Environmental Research Leipzig-Halle; Alemania

Apocynaceae have a precise pollination mechanism. However, broad pollinator assemblages, including several insect orders, have often been recorded. We test how the corolla tube length and operative width required for effective release of the pollination mechanism could restrict the pollinator assemblage in putatively hawkmoth-pollinated Apocynaceae that differ in flower depth. If corolla tube length were effective in filtering pollinators, a broader pollen vector assemblage would be expected in short-flowered species. For this to occur, the operative width of the pollinating apparatus would be additionally expected not to be specific to any particular pollinator. Alternatively, if the pollination mechanism were to have any effect in the exclusion of pollinators, access to short flowers would be expected to be limited by proboscis width rather than length. Pollination of three species in the Apocynaceae was studied in seven populations through direct observations and palynological analysis of hawk...

Karyotype data within a phylogenetic framework and molecular dating were used to examine chromosome evolution in Nierembergia and to infer how geological or climatic processes have influenced in the diversification of this solanaceous genus native to South America and Mexico. Despite the numerous studies comparing karyotype features across species, including the use of molecular phylogenies, to date relatively few studies have used formal comparative methods to elucidate chromosomal evolution, especially to reconstruct the whole ancestral karyotypes. Here, we mapped on the Nierembergia phylogeny one complete set of chromosomal data obtained by conventional staining, AgNOR-, C- and fluorescent chromosome banding, and fluorescent in situ hybridisation. In addition, we used a Bayesian molecular relaxed clock to estimate divergence times between species. Nierembergia showed two major divergent clades: a mountainous species group with symmetrical karyotypes, large chromosomes, only one nucleolar organising region (NOR) and without centromeric heterochromatin, and a lowland species group with asymmetrical karyotypes, small chromosomes, two chromosomes pairs with NORs and centromeric heterochromatin bands. Molecular dating on the DNA phylogeny revealed that both groups diverged during Late Miocene, when Atlantic marine ingressions, called the 'Paranense Sea', probably forced the ancestors of these species to find refuge in unflooded areas for about 2 Myr. This split agrees with an increased asymmetry and heterochromatin amount, and decrease in karyotype length and chromosome size. Thus, when the two Nierembergia ancestral lineages were isolated, major divergences occurred in chromosomal evolution, and then each lineage underwent speciation separately, with relatively minor changes in chromosomal characteristics.