Bark, also known as perierm, is the outermost layer of stems and roots of woody plants such as trees. It overlays the wood and consists of three layers, the cork, the phloem and the vascular cambium. Products used by people that are derived from bark include: spices and other flavorings, tannin, resin, latex, medicines, poisons, various hallucinatory chemicals and cork. Bark has been used to make cloths, canoes, ropes and used as a surface for paintings and map making; A number of plants are also grown for their attractive or interesting bark colorations and surface textures.