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.
Quinic acid Quinic acid Quinic acid is a cyclitol, a cyclic polyol, and a cyclohexanecarboxylic acid. It is a colorless solid that can be extracted from plant sources. Quinic acid is implicated in the perceived acidity of coffee. The compound is obtained from cinchona bark, coffee beans, the bark of "Eucalyptus globulus". It is a constituent of the tara tannins. Urtica dioica is another common source. It is made synthetically by hydrolysis of chlorogenic acid. Quinic acid is also implicated in the perceived acidity of coffee. This substance was isolated for the first time in 1806 by French pharmacist Nicolas Vauquelin and