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.
Tree trunk spider over an area of tree bark and wait hidden in plain sight for an insect to stray onto that patch. Once that occurs, they direct their spinnerets toward their prey and circle it; all the while casting silk on it. When the hapless insect has been thoroughly immobilized, they can bite it through its new shroud. For a picture, see or Tree trunk spider The tree trunk spiders are members of the tropical and semi-tropical family Hersiliidae. There are about 150 species in this family. These spiders have two very prominent spinnerets that are almost as long as their abdomen.