Basically, there are four types of plants suited to water gardens: deep water plants, bog plants or marginals, oxygenators, and floating plants. A mix of all four, properly planted, ensures a thriving, self-sustaining system. Lotus and water lily are two most well-known deep water plants. Bog plants include cattail; Japanese and water iris; bamboo; papyrus; and other tall, grasslike plants that thrive in the boggy, shallow areas that border the pond. Plants, such as water hyacinth, have beautiful flowers and keep the water clear of algae and blanket weeds by minimizing the amount of sunlight on the surface.