BLUE HILLS -- THE DOUBLE TREE

A Biologist's Explanation

There is a larger, more dominant tree on the right and a smaller, younger tree on the left. I believe two things happened here . . . . .
		First, the smaller tree on the left was damaged. It appears to have lost its terminal bud, that is the bud on the very top of the tree that has what is called apical dominance or the desire to grow towards the sun. When it lost this terminal bud the two upper most lateral buds started shooting towards the sun, competing for the status of terminal bud. It appears that the limb on the right side of the tree won and that is reflected in the abrupt jog to the right in the smaller tree. Secondly, it appears that the two trees grew close enough to rub together and slough off their bark exposing their growth layers, (xylem and phloem layers) and essentially performed a graft in much the same way a botanist might graft two apple trees together. Over the years these two trees have become as one, sharing the same shoot and leave systems.