I have bought lots of little and larger peaces of drift wood and have noticed mainly one thing. There is dark wood, light coloured wood and combo light and dark. I find it is best to get the dark coloured drift wood as the light has more of a chance of having fungus or hair algae. Here is a picture of hair algae on a peace of combo light/dark peace. Notice it only forms on the light parts and will not grow on the dark.
So a guy walks into a Pet Store
Guy: "I have Algae on my drift wood!"
Pet Clerk: "Take two Plecos and call me next week."
Sorry, but this doesn't prove out at all in my tanks. All my malaysian d-wood is the same uniform dark brown, and my mopani shows algae on the dark areas but not the light. Of course, the light streak on my mopani is positioned to show it off, which makes it a landing pad for every oto in the tank who, I'm sure, are lazy enough to prefer eating in than getting dressed up to go out.
Anybody else get the feeling there is an algea for all situations? If there is not an algea that grows someplace it is because we choose to call it something else. Dark wood often grows algea. If it were just a matter of color, we wouldn't have algea on glass as well as black filters. Sometimes we get lucky and sometimes we don't.