Tree tissue. It protects the trunk against the elements, disease, animal attack and fire. It is perforated by a large number of fine breathing pores called lenticels, through which oxygen diffuses. Bark is continually replaced by a living layer of cells called the cork cambium or phellogen. The London plane ("Platanus × acerifolia") periodically sheds its bark in large flakes. Similarly, the bark of the silver birch ("Betula pendula") peels off in strips. As the tree's girth expands, newer layers of bark are larger in circumference, and the older layers develop fissures in many species. In some trees such as the
Cedar bark textile Cedar bark textile Cedar bark textile was used by indigenous people in the Pacific Northwest region of modern-day Canada and the United States. Historically, most items of clothing were made of this material. The name is confusing, as it is made from "Thuja" (redcedar) and cypress bark, not cedar bark; true cedars are not native to the Americas. After the western redcedar or yellow cypress (often called "yellow cedar") bark was peeled in long strips from the trees, the outer layer was split away, and the flexible inner layer was shredded and processed. The resulting felted strips of bark were