Guayule grows in rocky, limestone desert areas in full sun. "Parthenium argentatum" (guayule) is a source of hypoallergenic latex. The name "guayule" derives from the Nahuatl word "ulli/olli", "rubber". Various other plants, including guayule and kok-saghyz (Russian dandelion), were investigated as rubber sources. U.S. indigenous populations of guayule occur in the Trans Pecos region of southwestern Texas. The guayule is grown in Mesa and Eloy, Arizona. The guayule project was abandoned after the end of World War I. Natural Rubber, ethanol, non-toxic adhesives, and other specialty chemicals can be extracted from guayule. Guayule is a plant that produces latex that can be used to make rubber. Guayule performs like "Hevea" but contains none of the proteins related to latex allergies.