- A burl is a large woody, rounded swelling, usually found on a tree trunk.
- "Burl wood" is prized for its unusual grain pattern. The grain of the wood swirls around each bud trace, forming interesting patterns in the wood.
- The cause of most burls cannot be explained.
- They may develop as a result of insects, bacteria, fungi, mistletoes, or environmental injury, such as freeze damage.
- Sprouts arising from the burl may be pruned off, otherwise, no treatment is necessary.
- Removal of the burl may damage the tree and is not recommended.