The Superior Express -

What is it? Where is it? This large knobby growth on the trunk of a tree is called a burl. Contrary to popular belief it is not harmful to the tree. In fact burls are prized by woodworkers for their beautiful patterns. This large burl nearly circles the trunk of a tree growing at the southwest corner of the vacant lot west of the Superior Auditorium.

Take a close look at the picture, the photographer thinks the burl looks like the head of a giant chipmunk but he hasnʼt found many people who agree with him.

A burl is a strange a strange looking collection of tree cells which are called callus tissue.

Normally callus tissue is formed by a tree in response to an environmental injury such as a pruning cut, disease or insect damage. In human terms burls may be compared to a fast-growing but non-malignant tumor.

Although burls grow into weird shapes and sizes on trees that otherwise look normal, a burl itself is not diseased or contagious.

The callus tissue that grows into a burl has several purposes, all related to tree growth and tree preservation. And because a treeʼs burl stores the same genetic material as the tree itself, it is a way for the tree to clone itself.

Burls grow both above and below ground.

Because of their grain, burls are often used in furniture making. They are not used where bearing weight is required.

Burls should not be removed as doing so may affect the health of the tree.