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Gardens

Plants: Species

Oak: Cork Oak Quercus suber

FAMILY: FAGACEAE (Beech family)

Wine lovers appreciate the cork oak Quercus suber, native to the Iberian Peninsula. This tree is the source of the thick, fatty substance, suberin, found in the bark that is commercially harvested to make corks used in wine bottles. Suberin keeps the cells in the bark elastic.


Cork really is a large group of cell shells of suberized cell-wall materials. One cubic inch contains about 200 million air-filled cells! The mature, dead outer cells of the bark must be harvested from the trunk with care so that the living tissue is not damaged. Injury could kill the tree. Harvesting may take place every 10 to 15 years, with a virgin tree yielding a cork thickness of 3 inches (8 centimeters).