Close interrelations between plants and animals have developed during evolution. In the garden and pastureland of Northeast Brazil one can study a fascinating symbiosis: some flowering plants don't offer nectar or pollen, but a fatty oil. They are called "oil flowers". The film documents the close interdependence between the bees (Centris) and plants (Scrophulariaceae) in their natural habitat. By means of macrography and slow-motion all phases of the bees' complex collecting behaviour are documented, including microscopic shots of the bees' legs. The flower structure is explained in detail. The film exemplarily introduces the basic mechanisms of a plant-animal interaction and the close connection between form and function in an ecosystem.