Burl

A burl is a fast-growing, rounded outgrowth on a tree that is filled with knots from dormant buds. Burls tend to yield interesting, highly figured timber and are prized by artists because of their unique shapes and patterns. Burls are typically produced when a tree, such as redwood or poplar, has experienced some type of environmental stress or damage, often caused by insects or a fungus. Guitar manufacturers are only now realizing the potential of burls in creating interesting tops or figured necks.