Cork oak (Quercus suber) belongs to the Fagaceae (the Beech family). It is a tall evergreen tree that is native to southwest Europe and northwest Africa. In the Mediterranean basin this tree is an ancient species dating back to the Tertiary period. This tree grows up to 20 m, although it is typically more stunted in its native environment. The leaves are ovate to ovate-oblong, weakly lobed or coarsely toothed, dark green above, paler beneath, with the leaf margins often downcurved. The acorns are 2-3 cm long, in a deep cup fringed with elongated scales. This tree forms a thick, rugged bark containing high levels of suberin. Over time the cork cambium layer of bark can develop considerable thickness and can be harvested every 7-10 years to produce cork. And this tree commonly live more than 200 years.