What is this growing on my driftwood?

[airedwin]

This is driftwood that has been out of tank, planning to add to tank but making sure it's safe? It is hard, is this fungus?

 

[Colin_T]

Probably. Hose it off and it should be ok

 

[emeraldking]

It does happen from time to time that when wood that's out of the water can turn white or show fungus. Just like Colin has already mentioned: Just hose or rinse it off...