Soft woods--hemlock and cypress usually--are used for mushroom bedding bins. Enzymes from the mushrooms break down the wood and give it an aged look. So it's not old, but looks old. And it's much less expensive than traditional reclaimed woods or new hardwood floors. We got it from The Hudson Company, and its rustic look is perfect for our house in the woods.
It goes well with the terra cotta tile in the rest of the house. (You can get a glimpse in the above picture.) And it has an interesting back story. Some mushroom wood comes from old coal mines in the Appalachians that have been converted into mushroom growing facilities. It has a lot of character.
Pictures of other mushroom wood projects here and here, and more about mushroom wood here.