Water lettuce is a free-floating subtropical plant found in still, fresh waterways such as farm dams, lakes and creeks. Like other floating aquatic plants, it has large, thick leaves that help in withstanding the weather and water movement. The leaves also have tiny hairs that offer more buoyancy.
The roots of water lettuce only anchor the plant in the water and are not for absorbing nutrients. Instead, the leaves absorb essential nutrients directly from the water. Water lettuce has no known food value to any wildlife and is considered an invasive pest species. Because these plants reproduce rapidly, they may cover a large part of a waterway quickly, depleting the oxygen supply in the water and resulting in fish kills.