Non-species-specific pollen transfer and double-reward production in euglossine-pollinated Vanilla.

· Commonly attributed to orchids, the pollen movement in Vanilla has been associated with food-deception and specific plant-pollinator relationships. · Here, the study was to investigate the role of the flower rewards and pollinator specificity in the pollen transfer of a widely distributed member to the euglossinophilous Vanilla clade, V. pompona Schiede. The analyses were based on data collected from Brazilian populations. They included investigation on morphology, light microscopy and histochemistry, and analysis of flowers scent by GC-MS. The pollinators and the mechanisms of pollination were recorded by focal observations. · The yellow flowers of V. pompona are fragrant and offer nectar as a reward. The major volatile compound of the V. pompona scent, carvone oxide, shows convergent evolution in Eulaema-pollinated Angiosperms. The pollination system of V. pompona is not species-specific, but its flowers are strongly adapted to pollination by large Eulaema males. Pollination mechanism is based in the combination of perfume collection and nectar seeking. · The dogma of the species-specific pollination system based on food-deception in Vanilla has been broken with the increase of studies in this Pantropical orchid genus. Here, I show that least three bee species and dual reward-offering are involved in the pollen transfer of V. pompona. The visitation frequency of bees collecting perfumes, which is used in the courtship by male euglossines, is higher than those searching for food. It is plausible, as the short-lived young euglossine males seem to be more interested in sex than food. A pollination system based on the offering of both nectar and perfumes as resources is shown for the first time in orchids.