Its pretty hard to actually positively identify wood especially weathered wood from an external view. If you really wanted a 100% certain ID you would need a fresh cross section and an expert. Even then without knowing where the wood came from you would probably need a microscope as well and an even better expert.
BUT with few exceptions most wood is perfectly fine in an aquarium. Those exceptions you will know pretty quickly after submerging if they are no good (they will stink your whole house up). If they are small enough to boil I would do that to them as it will help them sink and get rid of excess tannins. Otherwise give them a soak in a container for as long as you feel warranted and then use.