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
Bark spud (tool) Bark spud (tool) The Bark spud, (also known as a Peeling Iron, Peeler Bar, Peeling Spud, or abbreviated to Spud) is an implement which is used to remove bark from felled timber. Most bark spuds have steel heads and wooden handles, typically hickory or ash. The head is curved, sometimes in one direction with a single cutting edge, and sometimes more dish shaped and sharpened on three sides. In use, the sharpened edge is slid between the bark and the wood, removing the bark from the tree in a number of strips. It is especially useful at removing bark without