Bark

Bark, hard covering or rind of the stem, branches, and roots of a tree or other plant, as distinguished from the wood. The bark consists of an inner and outer layer. Bark is used commercially in the tanning of leather, in boatbuilding, and in basket making and in the manufacture of clothing and shoes, food flavoring, medicine, and cork and cork products.

Barks rich in tannin are usually used for tanning, although other properties also determine the value of a bark for preparing leather. Bark from several species of oak in the genus Quercus and from the Eastern hemlock (Tsuga canadensis) used to supply much of the tannin in the northern United States. In recent years, however, use of the wood or fruit of many other trees and the development of synthetic tannins have replaced earlier sources.

The Native North Americans used birchbark to cover canoes and tipis. Natives of Guyana make canoes of the bark of purple heart (Copaifera pubiflora) and of the locust (Hymenaea courbaril). In Saamiland, bark is used for baskets and shoes. Coats are made by the natives of British Columbia from pine bark, and garments of an elm bark were traditionally worn by the Ainu of Japan. Many peoples of Africa and Oceania make cloth from the bark of several trees.

The principal barks used for medicines and flavorings are discussed in separate articles: see Cascara Sagrada; Cinchona; Cinnamon; Witch Hazel.