Cork

Cork, spongy tissue in the bark of trees that acts as an insulation and protection to the delicate growing tissues. It also forms a seal over the wound where a leaf has been shed.

Commercial cork, used for insulation, bottle stoppers, engine gaskets, and floor linings, comes from the cork oak (Quercus suber) of southern Europe and North Africa. The cork oak has a layer of cork several inches thick that can be stripped every 10 years. The operation has to be carefully performed so that the delicate underlying tissues are not harmed.