Although many hardwoods, including oak, maple and rosewood, are used in furniture and construction projects, the hardest wood of them all is also hard to find. The tree Guaiacum officinale, which yields the wood lignum vitae, is the hardest wood in the world with a gravity of 1.37 and a maximum hardness of 4,500 pounds per square foot. This makes the wood strong enough for use in commercial boating and other strenuous tasks. Unfortunately, exploitation of this resource has driven lignum vitae, which means wood of life, to the endangered species list.
The yew tree was the tree of choice for British bow makers in medieval times. This was because the wood is strong yet flexible and would bend far before breaking. In fact, this quality -- along with the yew tree's high resistance to rot, infestation and weathering -- makes the yew tree the most resilient of trees. This resilience has paid off for the yew, which can live for 2,000 years or more.
...so I'm gonna say one of these two xd