Toxicodendron is a genus of in the sumac family, Anacardiaceae. It contains woody , and , including poison ivy, poison oak, and the lacquer tree. All members of the genus produce the skin-irritating oil urushiol, which can cause a severe allergic reaction. The generic name is derived from the Greek words ( toxikos), meaning "poison," and ( dendron), meaning "tree". ξ1 The best known members of the genus in North America are poison ivy (T. radicans), practically ubiquitous throughout most of eastern..
The narwhal, or narwhale ( Monodon monoceros), is a medium-sized toothed whale that possesses a large "tusk" from a protruding canine tooth. It lives year-round in the Arctic waters around Greenland, Canada, and Russia. It is one of two living species of whale in the Monodontidae family, along with the beluga whale. The narwhal males are distinguished by a long, straight, helical tusk, which is an elongated upper left canine. The narwhal was one of many species described by Carl Linnaeus in his publicatio..