The ecology and evolution of visual pollen signals

Abstract

By offering pollen and/or nectar as a food resource, angiosperms exploit flower visitors for pollen transport. Pollen thus acts not only as a means for transportation of male gametes, but also as a food reward for potential pollinators. Many findings provide compelling evidence that pollen acts, in addition, as a visual signal. The present contribution reviews several strategies that angiosperms have evolved to attract potential pollinators to the site of reward. We here consider evolutionary, ecological, sensory-physiological, and behavioural aspects of flower-pollinator interactions that are correlated with visual signals provided by pollen and pollen-producing organs, or imitations thereof.