The nasturtium plants used in this exhibit have water-resistant leaves that cause water droplets ride on a thin layer of air. This phenomenon, also seen in plants such as lotus and kale, helps the leaves stay clean and free of pathogens. The surface of the leaves are covered with microscopic wax crystals that repel water, and are spaced so closely together that water just rides on the surface instead of filling all the gaps. This physical trait has been dubbed the "lotus effect" and is an active area of study for creating self-cleaning surfaces.
