This item is one of the clues in the Assassin's Roost Quest. You must have looked at the Open Book for it to mean anything to you though.
Some trees found on the landscape can also be picked up. Give any you have to the Tree Craftsman near Yanshi at 12.9S, 41.6E to help with the wedding preparations.
You lean trying to disern the purpose of the carving on this tree.
Just as confusion as to the purpose of this mark sets over you a voice on the wind reaches its way to your ear.
It says "Bring a heart of mud to a Gharu'ndim collector of such."
You think that this is what you were meant to learn here and you should now be on your way.
If you have not looked at the book yet:
There is a mark scratched into this tree but it doesn't mean anything to you.
