area where a subdominate branch joins another branch or trunk that is created by the overlapping vascular tissues from both the branch and the trunk. Typically enlarged at the base of the branch.
A branch collar is the "shoulder" between the branch and trunk of woody plants; the inflammation formed at the base of the branch is caused by annually overlapping trunk tissue. The shape of the branch collar is due to two separate growth patterns, initially the branch grows basipetally, followed by seasonal trunk growth which envelops the branch.
|Plant Structural Member
Branch collars serve as a strong foundation to the branch, and its orientation and internal characteristics allow the branch to withstand stress from numerous directions. Functionally the branch collars also influence the conductivity of nutrients and growth patterns.
The branch collar which provides a protective barrier to prevent infection and decay, can also be useful in diagnosing bacterial diseases.
Proper pruning techniques should accommodate for the branch collar structure, as by damaging the tree it is likely to decay or become diseased.