Ptelea trifoliata, commonly known as common hoptree,[4] wafer ash,[5] stinking ash,[6][4] and skunk bush,[7][8] is a species of flowering plant in the citrus family (Rutaceae). It is native to North America, where it is found in Canada, Mexico, and the United States. It is a deciduous shrub or tree,[9][10] with alternate, trifoliate leaves.