Cypress Knees

As we travel we enjoy learning about the plants that we don't have here in PA.  Certainly this caught our eye.  The growth habit of these  Bald Cypress Trees has this distinctive root function.   Scientists aren't completely sure why they do this: part of the reasoning is for balance in the muddy, swampy water.  Some scientist have thought the Cypress tree does this for oxygen.  The knees are hollow and are often cut off and sold or carved.  Cutting off the knees does not seem to harm the plant in any way.  The knees can reach 3 inches and up to 5 or 6 feet above the ground depending on the depth of water the tree is in.