Slippery Elm Bark is derived from the Slippery Elm tree, a deciduous tree that grows on the eastern coast of the United States. The tree's Latin name is Ulmus rubra, and rubra in Latin means red. In this case it refers to the red heartwood of the tree. This is why it goes by the common name of Red Elm, along with other common names such as Moose Elm, Gray Elm, Soft Elm and Indian Elm.
Slippery Elm Bark, or Ulmus rubra, is an herb derived from the inner part of the elm bark and is usually used as a finely ground powder. It is not advised for pregnant women to consume this bark.