Even among submergent plants, pollination and seed dispersal usually take place above the water's surface. Wild celery produces male and female flowers. The female flowers are suspended on long stalks extending to the surface. Male flowers develop underwater, float to the surface, open, and drift until they contact a female flower. The female flower is pollinated and then coils down into the water, where the seeds develop.
Wind carries pollen from the male to the female flowers.
After the seeds develop, the water transports them until they settle in a suitable location. Many aquatic plants use vegetative reproduction some or all of the time. Cattail, pondweed, and water lilies all produce thick rhizomes which serve for both reproduction and food storage. Arrowhead produces tubers, popularly called duck potatoes. The tubers survive over the winter and produce new plants in the spring.