I've never heard of it used for smoking anywhere...come to think of it, I've never heard of it's existence.
I just checked Dutch's post for a minute...nothing about it. I'd say until proven different, consider it toxic. Maybe get it seasoned well and burn some in a barrel or metal bucket and check the odor, smoke, soot, and watch for saps/creosote when heated/burning. Also, try to chip it with a small hatchet/axe, or wittle it to see if it is a hardwood or not. See if it can give off good charactoristics. I wouldn't try in a smoker until I knew for sure though, the smoke residue in your rig might be less than desirable.
I don't know, but, it sounds like alot to go through...maybe a ground breaker though.