I think I'm going to change "Hardest" to "Tough and Versatile" because we don't have a use case as yet to narrow things down. However, an extremely tough and versatile wood in North America is the Osage Orange Maclura pomifera. It's also known as the Hedge Tree. It is also the plague of anyone who has a need to cut one down in their own yard.

1. The Hedge Tree is pretty Tough, the toughest in North America with a Janka Hardness of 2040 when green and it gets harder as it dries out, reportedly up to 2700. This is about 2 times as much as the hardest of Oaks. I have seen it recommended that you do any carving when the wood is still green because you won't be able to when it dries.

2. It is somewhat flexible. When combined with the hardness, it becomes a prized Bow makers wood. Native Americans would travel quite a long way to harvest limbs from an Osage Orange for bows.

3. It is very resistant to Rot. It is frequently used for fence posts because it will last below grade (in the ground) for a long, long time. It doesn't get mildew or molds getting deep into the wood. Bugs also seem to avoid the wood. The fruit is often used as a natural insect repellent.

4. It's Dense. This wood will eat chainsaws. I know this from having to cut one down in my yard. It was about 12 years old and it took 3 chainsaw chains to get through. Granted, I have a cheap chainsaw, but still. Incidently I still have a huge part of the trunk that is heavy as heck and I want to do something with it, but I don't know what yet.

5. it burns HOT! When used as firewood it will put out about twice the eat in BTU's as most varieties of oak. It pops a lot, so not good in an open fireplace, but in a sealed wood stove I was able to keep my house at about 80 degrees f during a snowstorm where outside was 12 f.

6. It grows in a variety of climates and soils. It was used in the Midwest to create windbreaks and to help with soil erosion during the Dust Bowl.

So for what is possibly the toughest and most versatile natural wood that actually exists, Osage Orange Maclura pomifera is your friend. It would also make a good basis for any sort of monkeying around you may want to do with it's genes.

I think I'm going to change "Hardest" to "Tough and Versatile" because we don't have a use case as yet to narrow things down. However, an extremely tough and versatile wood in North America is the Osage Orange Maclura pomifera. It's also known as the Hedge Tree. It is also the plague of anyone who has a need to cut one down in their own yard.

1. The Hedge Tree is pretty tough, the toughest in North America with a Janka Hardness of 2040 when green and it gets harder as it dries out, reportedly up to 2700. This is about 2 times as much as the hardest of Oaks. I have seen it recommended that you do any carving when the wood is still green because you won't be able to when it dries.

2. It is somewhat flexible. When combined with the hardness, it becomes a prized Bow makers wood. Native Americans would travel quite a long way to harvest limbs from an Osage Orange for bows.

3. It is very resistant to rot. It is frequently used for fence posts because it will last below grade (in the ground) for a long, long time. It doesn't get mildew or molds getting deep into the wood. Bugs also seem to avoid the wood. The fruit is often used as a natural insect repellent.

4. It's dense. This wood will eat chainsaws. I know this from having to cut one down in my yard. It was about 12 years old and it took 3 chainsaw chains to get through. Granted, I have a cheap chainsaw, but still. Incidently I still have a huge part of the trunk that is heavy as heck and I want to do something with it, but I don't know what yet.

5. it burns hot! When used as firewood it will put out about twice the eat in BTU's as most varieties of oak. It pops a lot, so not good in an open fireplace, but in a sealed wood stove I was able to keep my house at about 80 degrees f during a snowstorm where outside was 12 f.

6. It grows in a variety of climates and soils. It was used in the Midwest to create windbreaks and to help with soil erosion during the Dust Bowl.

So for what is possibly the toughest and most versatile natural wood that actually exists, Osage Orange Maclura pomifera is your friend. It would also make a good basis for any sort of monkeying around you may want to do with it's genes.