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.
Jesuit's bark "Pulvis Patrum". The history of cinchona bark, which dates back more than 300 years, has greatly influenced that of pharmacy, botany, medicine, trade, theoretical and practical chemistry, and tropical agriculture. Circa 1650, the physician Sebastiano Bado declared that this bark had proved more precious to mankind than all the gold and silver that the Spaniards had obtained from South America, and the world confirmed his opinion. See also Swords, Ships and Sugar - The History of Nevis, by Vincent K. Hubbard, p. 73, where a large amount of "Peruvian Bark" had been captured by the pirate Basil Ringrose, also known