Callus On Tree Trunk. The external female genitalia ( vulva ) can assume many different colors. Different women have labia of different thicknesses and lengths.
Vulva © Susan Lener
Callus closing the wound in the trunk of an old tree caused by sawing off a branch. A tree branch has a branch bark ridge, often referred to as a branch collar, that separates the branch from the tree trunk. The collar is the swelling located at the base of a branch where the branch meets the trunk. The callus that forms the collar is an area of tissue that contains a chemically protective zone. The natural decay of a dead branch stops when it reaches the collar. When pruning a dead branch, a new wound should not be created by cutting into the ring that forms around the dead branch. Externally, callus tissue develops around the injury and should eventually cover it by growing over the bare wood. The black coloring inside the callus comes from a pruning compound applied after the branch had been removed.