“Quercus suber” The cork oak tree is covered in thick, knobby bark that was probably developed for forest fire survival. This is where the cork comes from. When harvested, the tree is left standing while the bark is peeled off and cut from the tree. The bark eventually grows back and can be reharvested every nine to twelve years. A healthy cork oak that lives to be two hundred years old can be harvested up to sixteen times. Portugal has the largest number of cork oak trees in the world and is subsequently the worlds leader in cork production.