It is made by drying the inner skin of slippery elm and turning it into a powder. In North America, Native Americans have been using this plant since ancient times. Slippery Elm Bark, Powder Botanical name: Ulmus rubra Family: Elm family Part: Inner bark Also known as: Akaharu Nire / Aka Nire Country of origin: United States *The country of origin is subject to change without notice, depending on climate and other factors.