Money doesn’t grow on trees, so it should stand to reason that diesel fuel wouldn’t grow on trees either. And yet the Brazilian Copaifera langsdorfii tree has been quietly producing a natural diesel variant in the tropical rainforest, something we’ve known about since the seventeenth century. It’s only now that farmers in Australia have decided to farm the tree on a large scale in the hopes of having 20,000 living, above-ground fuel wells.