PlanetCatfish.com

I bought this piece of driftwood a while back, and at the time of purchase I really didn't consider the white stuff attached to it. Recently, however, I've become a little more weary about what I put in my tank and so, naturally, I've become weary of what's on this piece.

It's fairly hard to the touch, but it will scrape off.(albeit, scraping it off would be a chore) I tried to soak it and see if that made it easy to remove, or if it would just remove itself, but that wasn't the case either way.

Any thoughts on what it is and what to do with it?

Not sure what it is, but if You are worried I would just hit the entire piece with a wire brush, let it dry out, and try again.
-Shane

fungus; actually it's a kind of toadstool, like Elfbark (or whatever you call it in English).

harmless, but it can rot and hence pollute your water; it's not toxic.

BUT it's a hint that your bogwood is actually not good; true bogwood is so old and so saturated with peatbog-chemicals it doesn't rot.....

Avoid a LOT of trouble and get another piece of bogwood!