Burl wood is a type of wood used by artists to create sculptures and other items, such as clocks and even some forms of furniture. Burl wood is highly prized by artists because of its unique shapes and ring patterns. Burl wood is a type of fast growing, abnormal growth found on some trees. Burl wood grows because the tree has experienced some sort of environmental stress or damage. This is often caused by either a fungal attack or an attack by insects.

The number of trees that produce burl wood is quite low. In addition, certain areas tend to create more burl wood than others, because all or many of the trees in a particular location are likely to be attacked by the same fungus or insects. Certain species also tend to be more susceptible to attacks and, therefore, more likely to develop burl wood. For this reason, certain types of burl wood are more rare and prized than others.

Often, a tree that has developed burl wood is still quite healthy. In fact, many trees with burl wood can go on to live for many more years. Other trees develop burl wood offshoots that are so large and heavy that they create additional stress on the tree and can cause the tree to die.