It turns out that this plant's immune system has kept the root rot from doing a lot of damage. Note - all living systems must have an immune system. There are lots of things in the environment that will kill any organism without an immune system. The orange patches are the fungus that rotted the roots entering the body of the plant. I want to save the plant, so I decided to carve more of the fungus-invaded body away to give the treatment a better chance of being effective.