Burl

A burl is a growth or abnormal swelling that forms on a tree's trunk or branches, often looking like a large, rounded, and knotted lump. It occurs when the tree's cells undergo unusual growth due to pests, injuries, or genetic factors. Burls contain a dense, intricate grain and many small, tightly packed wood fibers, making them prized for woodworking and artistic projects. Despite its appearance, a burl generally doesn't harm the tree significantly but is valued for its unique, decorative qualities in woodworking.