[(Slippery Elm Bark, U. S.)
Sp. Char.—Leaves very scabrous above, rather unequal, and somewhat cordate at base. Buds clothed with a fulvous tomentum. Flowers in dense sub-sessile fascicles. Samara orbicular, naked on the margin. (Beck. Bot.)
This tree is sometimes called also Red Elm. It is from 20 to 40 feet high, with rugate branches. The leaves are from 4 to 6 inches long, and 2 or 3 inches broad, lanceolate oval, or obovate oblong, conspicuously acuminate, doubly serrate, the upper surface scabrous, beneath tomentose pubescent, especially along the nerves and midrib, petioles about one-third of an inch long, pubescent. Stipules pilose. Flowers on short pedicels, numerous, in dense lateral clusters. Calyx about 7 cleft; segments obtuse, clothed and ciliate, with a reddish tawny pubescence. Stamens often 7, much exserted; anthers dark-purple. Styles granular pubescent, purple. Samara orbicular, about half an inch in diameter, radiately veined, pubescent in the centre, on a slender pedicel as long as the calyx; margin smooth, cleft at apex between the styles; segments acuminate by the pubescent adnate styles, and so incurved and over-lapped as to give the margin the appearance of being entire at apex. (Darlington.)
This plant is common in the United States, growing in low grounds and along fences.
The inner bark is fibrous, and is removed from the trunk and large branches of the tree in long pieces. It is found in the shops in this form or ground into powder. It is bland and demulcent, and is used as a substitute for flaxseed and other demulcent articles. From the powder can be made an excellent poultice by mixing with the requisite quantity of hot water.
INFUSUM ULMI, U. S.; Infusion of Slippery Elm Bark.—Made by macerating an ounce of Slippery Elm Bark in a pint of boiling water. Used for the ordinary purposes of a demulcent solution.]
The Elements of Materia Medica and Therapeutics, Vol. II, 3th American ed., was written by Jonathan Pereira in 1853.