Basal Flare – The rapid increase in diameter that occurs at the confluence of trunk and root crown, associated with both stem and root tissue.
Best Management Practices – The best available treatments, considering the benefits and drawbacks, based on current knowledge.
Bleeding – Flow of sap from wounds and/or other injuries.
Bole – The central stem of the tree.
Bow – The gradual curve of a branch or stem
Bracket – Fruiting or spore producing body of wood decay fungi, forming on the external surface of the stem or trunk.
Branch – A secondary shoot or stem arising from the main stem of trunk.
Branch Angle – The angle of attachment between two stems; also referred to as crotch.
Branch Attachment – The structural linkage of branch to stem.
Branch Bark Ridge – A ridge of bark in a branch crotch that marks where branch and trunk tissue meet and often extends down the trunk.
Branch Collar – Wood that forms around a branch attachment, frequently more pronounced below the branch. The branch collar is used to identify the correct location of all thinning cuts.
Branch Protection Zone– A thin zone of starch-rich tissue at the base of a branch into which chemicals are deposited to retard the spread of discoloration and decay.
Brash Wood – Type of reaction wood which is weaker than normal due to thin cell walls and decreased fiber content; presence increases the likelihood of failure.
Brown Rot – Form of decay where cellulose is digested. The result of brown rot is brittle wood with no tensile strength.
Buttress – Support branch, stem, or root; usually associated with exaggerated growth.