The Physiomedical Dispensatory by William Cook, M.D., 1869    

SILPHIUM PERFOLIATUM

CUP PLANT

Description:  Natural Order, Compositae.  In the same genus with the preceding, but quite different in general appearance. Stem four to eight feet high, stout, square, often branched above. Leaves opposite, connate, six to fifteen inches long, thin, the upper pairs united by their bases so as to form a hollow or cup around the stalk.  Flowers nearly as in the preceding plant. Common in rich soils by the borders of streams through the West and South. July.

Properties and Uses:  The root of this plant is among the stimulating relaxants, moderately diffusive in action, and of a gently tonic character.  A warm infusion is diaphoretic, and sustains the capillary circulation; and is used in colds, catarrh, and bilious and remitting fever.  Cold preparations are somewhat alterant, and are said to be of value in intermittents, biliousness, and ague cake.

 Medical Herbalism journal and medherb.com