Pith

Pith in lumber refers to the central core of a tree trunk, which is comprised of soft, spongy tissue that contains cells that are still alive. When a tree is cut down and sawn into lumber, the pith is typically found near the center of the log and may be visible as a small, circular or oval-shaped area in the center of the cut lumber.

The pith is typically softer and less dense than the surrounding wood, and may be more susceptible to cracking, warping, or other forms of damage. For this reason, lumber with a large amount of pith is generally considered less desirable than lumber with a smaller amount of pith.

In some cases, lumber with a large amount of pith may be rejected outright, as it may not meet certain quality standards or may not be suitable for certain applications.