Discolored Wood  - Discolored wood is wood that is chemically altered as a result of a wound or injury.  Discolored Wood -cell contents and walls altered, color change.  Not really discolored as meaning further from color.  Often color increases.  Discolored wood is wood infected by non-hymenomycetous, or non-decay causing fungi.  In the early stages, discolored wood is a protection wood, but in later stages, as more organisms infect, the wood may lose its protection properties. As this happens, the discolored wood may take on the characteristics of soft rot where the S2 layer of the secondary layer of fibers is infected and altered.  Discolored wood is initiated by wounds and the death of branches and roots that are not effectively walled off.  Bacteria and fungi that are not capable of decaying wood usually infect the wounds and the tissues associated with branches and roots that are not effectively walled off.

The "heartrot concept" was based on the false premises that "wood is dead" and that "when a tree is wounded, it forms heartwood".