my bo staff is made of a wood called purpleheart. its one of the densest woods. its very heavy, and when you pick it up, there is no doubt that you're holding a real weapon, which is why I like it. Its extremely durable. I was introduced to the wood at the renaissance faire, when I was doing quarterstaff fighting. Most of the weapons were either oak, ash, or purpleheart. Its an expensive wood, but very beautiful, and very strong.
Purpleheart is a purplish brown color (almost an auburn) and its a really beautiful wood. My kama handles are also made of purpleheart, and I've been looking into having some sais made with purpleheart grips.
the downside to this wood is that it is HEAVY. it takes a lot more effort to do a lot of the fancy stuff that you can with a light toothpick style bo, but I think its worth the sacrifice.