Botanical name: 

The rhizome of Jeffersonia diphylla, Barton (Nat. Ord. Berberidaceae). A handsome, vernal, flowering plant throughout the eastern half of the United States.
Common Names: Twinleaf, Rheumatism Root.

Principal Constituents.—A large proportion of an undetermined white alkaloid, saponin, and a trace of berberine.
Preparation.—Tinctura Jeffersoniae, Tincture of Jeffersonia. (Jeffersonia, 8 ounces; Alcohol (76 per cent), 16 fluidounces.) Dose, 10 drops to 1 fluidrachm.

Action and Therapy.—As indicated by one of its trivial names this plant has been used in chronic forms of rheumatism. Its exact status is not well determined, but it is undoubtedly alterative and has some effect upon the general nervous system, allaying excitability and irritability. Watkins declared it efficient in pain in the head with dizziness and feeling of tension. Locke mentions it as useful where rheumatism is located chiefly in the muscles of the back, and in bronchitis and constitutional chronic catarrh, especially in the aged.

The Eclectic Materia Medica, Pharmacology and Therapeutics, 1922, was written by Harvey Wickes Felter, M.D.