also called poison elder Attractive, narrow shrub or small tree (Rhus vernix or Toxicodendron vernix) of the sumac, or cashew, family. It is native to swampy acidic soils of eastern North America. Unlike the upright reddish, fuzzy fruit clusters of other sumacs, whitish waxy berries droop loosely from its stalks. The clear sap, which blackens on exposure to air, is extremely irritating to the skin for many people