mycelium of a saprophyte mushroom

This fungi was growing on a piece of old plywood I pulled out from under our camp. It was so beautiful that I had to take a picture. It appeared to branch out from the white and tan mass pictured on the right corner. Its spread was quite large across the board. Note received: "This is just the mycelium of a saprophyte mushroom, I can't really say which because there is no fruiting body - the part that we recognize as the mushroom."