Agradecimentos: This research was partially financed by the Coordenação de Aperfeiçoamento de Pessoal do Nível Superior – Brazil (CAPES). We thank: Fundo de Apoio ao Ensino, Pesquisa e Extensão (FAEPEX)/Unicamp for financial support and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) grant 302781/2016-1 to M.S.; the Itatiaia National Park directors; NAP/MEPA, ESALQ/USP; Centro de Microscopia e Imagem, (FOP/UNICAMP) and LBCM/CENA, for maintaining the electron and light microscopes, respectively; Laboratório de Fisiologia Molecular de Plantas (LaFiMP) (UNICAMP) and Malgorzata Stpiczynska for comments that improved the manuscript Ver menos

Abstract: Nectar is an important floral resource in the establishment of plant-pollinator interactions. Recent studies have shown that nectariferous tissues are independent of the ABC model of floral development and that ecological interactions can modify their expression. In this sense, it would be interesting to study generalist species in relation to nectar production and nectary morpho-anatomy to verify the strategies used to attract different pollinator groups. We recorded nectar production dynamics in Aechmea vanhoutteana (Bromeliaceae) from a morpho-functional and ultrastructural perspective. We observed different species of hummingbirds, bees and butterflies visiting flowers of A.vanhoutteana, and their frequency varied throughout floral anthesis. The nectar volume and quantity of sugar also varied significantly during anthesis, and this spatial and temporal variability seems to be related to an increase in bee visits, representing an important aspect of the reproductive strategy of this species, since bees can fly longer distances than the observed hummingbirds (although both have territorial behaviours). Thus, it can be suggested that anatomical and physiological nectar traits may be related to pollen flow, an important aspect of the reproductive strategy of A. vanhoutteana, suggesting plant resource allocation for optimizing reproduction through nectar production Ver menos