Capillarity driven hydrophilous pollination in ruppia maritima l. (widgeon grass, ruppiaceae)

This work involves modelling the mechanisms of two-dimensional aquatic pollen dispersal, known as hydrophily, that have evolved in several genera of aquatic plants. Our focus is on Ruppia maritima, a species of seagrass, for which the pollen released from male inflorescences is transported to the stigmas present on the water surface by a multi-step mechanism relying heavily on the surface tension of water. Male inflorescences rise above the surface and dehisce their pollen masses onto the surface, or remain below the surface and produce bubbles which carry their pollen masses to the surface. In both cases, heavier than water pollen masses partially disperse as they come in contact with the surface increasing their contact line perimeter allowing them to float on the surface, and subsequently combine to form pollen rafts under the action of lateral capillary forces. The presence of a trace amount of surfactant, however, can disrupt one or more of these surface tension dependent steps, and thus completely stop pollination