Knuckle Trees

This is a detail of a sycamore tree that has been pruned using a method called pollarding. "When a tree is pollarded, the outer branches are seasonally cut to a predetermined joint, causing a callus to form over the area. With each subsequent pruning a new callus develops, resulting in big, bulbous knobs."

They are known as the Getty Knuckle Trees.

See Large for details.