BURLS, BURRS, BUTTRESSES and KNOTS
Trees are unique organisms that can create extremely interesting wood configurations during some types of growth. Not all tree abnormalities are a bad thing. What on one level appears to be a fatal cancer-like growth can prove to have hidden qualities that can be unearthed by a lathe and gouge.
Burls or burrs are tree growth areas in which the inner grain has developed in a deformed manor. It is commonly found in the shape of a rounded outgrowth on a tree trunk or branch. It is usually filled with small knots formed from dormant buds which gives it its unique character. The wood's character is amplified because growth rings are usually not present, replaced by the deformed wood development.