Cypress Knees

These odd shaped wood, protruding like a warning finger, are called "cypress knees". The dead roots spear up into the air. A cypress knee is actually part of the root system of the cypress tree. Because the cypress tree lives in a swampy area, its roots are mainly submerged. The knees are the parts of the roots that stand above the water level and they help bring oxygen to the tree.
They come in such odd shapes, easy to trip on.