The word “bough” often appears in poetry, literature, and carols, referring to a major limb or structural arm of a woody plant. This specialized term describes a large, sturdy part of the tree’s architecture that holds a significant place in its overall form. Understanding the bough requires comparing its physical characteristics to the more common term, “branch.”
Defining the Bough
A bough is defined as a large, primary limb that extends directly from the trunk or main stem of a mature tree. This substantial section of wood is a major subdivision of the tree’s axis, built to bear significant weight. Boughs are sometimes referred to as “scaffold branches” because they form the foundational framework of the tree’s crown. These large limbs serve a structural purpose, supporting the countless smaller branches, leaves, flowers, and fruits that make up the canopy. The robust nature of a bough allows it to distribute the weight of the tree’s expansive foliage and absorb external forces like wind and snow.
Bough Versus Branch
While the terms are often used interchangeably in everyday conversation, a bough is distinct from a general branch based primarily on size and location. Every bough is technically a branch, but the term “bough” is reserved for the largest, most substantial divisions of the tree’s crown. A branch, in contrast, is a far more general term that applies to any woody offshoot from the main stem or another branch, regardless of its diameter.
The hierarchy of a tree moves from the trunk, to a bough, to a branch, and finally to a twig, which is the smallest, newest growth. For example, a branch might sprout from a bough, and a twig might sprout from that branch, but the bough itself must originate directly from the trunk or be a primary division of it. This distinction emphasizes the immense size and thickness of a bough, which is often considered the main support structure for the smaller, more flexible lateral branches. The use of “bough” over “branch” often carries a more traditional or poetic connotation, highlighting the sheer scale and strength of the tree’s primary arms. In technical terms, professional arborists sometimes use the word “limb” as a synonym for bough, referring to any large division of the stem axis that bears foliage.