CORK OAK, tree found in the Mediterranean. Its very thick, soft, fissured bark is used to make bottle corks. The first crop of bark is taken when the tree is about 15 years old to be used in tanning and cork boards. From then on the bark can be removed every 10 or 20 years. The tree will crop for 150 years. Cork oak occurs westwards from the Adriatic coast and is abundant in Spain and Portugal.
Trees and shrubs of the Mediterranean by Helge Vedel, translated from the Danish by Aubrey Rush (Penguin Guides, 1978), p36.