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
Striped bark scorpion phosphatase, and phospholipase A. While a "C. vittatus" sting is not typically deadly, and signs such as swelling can be treated using an ice pack, several other species from the genus "Centruroides" can have a deadly sting and medical attention should be sought immediately. Striped bark scorpion The striped bark scorpion ("Centruroides vittatus") is an extremely common scorpion found throughout the midsection of the United States and northern Mexico. It is perhaps the most frequently encountered scorpion in the U.S. A medium-sized scorpion that is rarely longer than 70 mm (up to around 2 3/4 in), the striped bark scorpion