Which anatomical feature marks the junction where a branch attaches to the trunk?

• A. Heartwood
• B. Xylem
• C. Branch collar
• D. Sapwood

Answer: (C)

The junction where a branch meets the trunk is marked by the branch collar. This collar is a band of tissue that forms at the base of the branch where bark, cambial tissue, and wood meet, creating the natural boundary between branch and trunk. It acts as the tree’s built-in wound-defense zone, guiding healing and stump closure when a cut is made. In pruning, you want to cut just outside the branch collar so the tree can efficiently seal the wound with callus tissue. Heartwood and sapwood are different wood layers, and xylem is the water-conducting tissue; none of these indicate the boundary between branch and trunk.