Bark (botany) rope, used for example in the rigging of Viking age longships. Among the commercial products made from bark are cork, cinnamon, quinine (from the bark of Cinchona) and aspirin (from the bark of willow trees). The bark of some trees notably oak ("Quercus robur") is a source of tannic acid, which is used in tanning. Bark chips generated as a by-product of lumber production are often used in bark mulch in western North America. Bark is important to the horticultural industry since in shredded form it is used for plants that do not thrive in ordinary soil, such as epiphytes.
Christmas tree production in the United States million Christmas trees valued at approximately $120 million. The majority of Christmas tree production occurs in the Willamette Valley region including Benton, Clackamas, Marion, Polk and Yamhill counties. In 2015, Washington State had approximately 250 Christmas tree farms with a combined 23,000 acres, yielding 2.3 million Christmas trees valued at approximately $35 million. The majority of Christmas tree production occurs in the western and southern portions of the Puget Sound region including Kitsap, Lewis, Mason and Thurston counties. Aside from Pennsylvania, several U.S. states in the Great Lakes region are key Christmas tree producers. The two most important production areas