---Description---The Slippery Elm is a small tree abundant in various parts of North America. The branches are very rough, the leaves long, unequally toothed, rough with hairs on both sides, the leaf-buds covered with a dense yellow Wool. The flowers are stalkless. The inner bark has important medicinal value and is an official drug of the United States Pharmacopoeia. The bark, which is the only part used, is collected in spring from the bole and larger branches and dried. Large quantities are collected, especially in the lower part of the state of Michigan. As the wood has no commercial value, the tree is fully stripped and consequently dies