Lignum Vitae, the national tree of the Bahamas, is the most cumbersome and most laborious wood in the world. Even the world’s first nuclear-powered submarine had its bearings made out of this wood. It also contains natural oils that make the bearings self-lubricating, which makes it an excellent wear-resistance.
Unfortunately, Lignum Vitae has been exploited to the brink of extinction. It is now on the list of endangered species.