I recently cut a large dead standing osage. I just made a sweet shooting little bow from the crappiest looking belly split on the tree. There is some really fine looking bow wood in this tree, but this particular piece had some strange looking discoloration in patches. I am guessing that there were periods of standing water or at least heavy moisture near the middle of the tree, or maybe some sort of fungal growth. Whatever the cause, there are patches of reddish brown colorations in this stave. I tillered right through these areas and found those places to be extremely hard wood - harder than the surrounding yellow wood. This bow was mostly an experiment to see how this discolored osage would do. The bow performs well and took very little set. I was wondering if anyone else had seen this and if you know for sure what caused it.