: Looks like a fungus. Was it there when you cut it, or did it appear
: after you cut it? What is the temp and humidity in your shop?
: Testing is good. Add using bleach or a mildew stain remover
: product to your tests as well.

: m

It appeared after milling the strips. The board was a little damp when I cut it and I am in Houston so there is always humidity. I think you guys are right, it is probably a fungus. I have sanded a sample and epoxied it, now I will play the waiting game and see if it reappears. I had high hopes to start stripping this weekend but I guess it will get put on hold for another week.

Thanks for all the responses and thanks to Kurt for turning me on to this forum!