Urushiol /ʊˈruːʃi.ɒl/ is an oily mixture of organic compounds with allergenic and sensitizing properties found in plants of the family Anacardiaceae, especially Toxicodendron spp. (e.g., poison oak, Chinese lacquer tree, poison ivy, poison sumac), Comocladia spp. (maidenplums), Metopium spp. (poisonwood), and also in parts of the mango tree and the fruit of the cashew tree.
In most individuals, urushiol causes an allergic skin rash on contact, known as urushiol-induced contact dermatitis.
Sumac or sumach (/ˈsuːmæk, ˈʃuː-/ S(H)OO-mak, UK also /ˈsjuː-/)—not to be confused with poison sumac—is any of the roughly 35 species of flowering plants in the genus Rhus (and related genera) of the cashew and mango tree family, Anacardiaceae. However, it is Rhus coriaria that is most commonly used for culinary purposes. Sumac is prized as a spice—especially in Iranian cuisine, and other Eastern cuisines—and used as a dye and holistic remedy. The plants grow in subtropical and temperate regions, on nearly every continent except Antarctica and South America.Native to Persia, it holds cultural significance as a symbolic item on the Haft-sin table during Nowruz, the Persian New Year.