Knees in the Swamp

Ms. Nastee found an Atamasco lily growing right next to some "knees". Scientists have thought that cypress trees sent up these protuberances (bumps) to help get oxygen to the roots. Now many believe these bumps are used to provide support and stability to these cypress trees. Why is the water green? Duckweeds, small aquatic plants that grow on the surface of the pond, are eaten by ducks, and other creatures, such as frogs, hide in them.