Cypress trees are the most grown, highly flood-tolerant wetland trees in Florida. The trees grow extensively on river and lake banks, and swamps in the state. When growing near water bodies, the trees produce distinct, protruding stumps referred to as knees. Specific Florida laws address the legality of harming these knees.
It is illegal to cut the knees on cypress trees growing on state land without a state permit, according to the Orlando Sentinel. The knees are widely used for making tables and lamps. Cypress knees are protected under the wetland preservation laws in Florida.
Knees are more common on cypress trees that are growing in flooded areas, and possibly help the trees stay stabilized and anchored in muddy ground, according to the University of Florida Extension. Extensions of the tree's root system, knees help to absorb oxygen from the air. The rate of respiration in knees increases with the water level.
The size of cypress knees range from a few inches to up to 12 feet depending on water depth. The bark on the knees is lighter colored than the tree and the wood texture is also softer.