The leaves and branches of Viscum flavescens, Pursh (Nat. Ord. Loranthaceae). A parasitic plant found upon forest trees, especially the oaks in America.
Common Names: Mistletoe, American Mistletoe.

Principal Constituent.—Viscin, a viscous substance also known as bird glue or bird lime.
Preparation.—Specific Medicine Mistletoe. Dose, 1 to 30 drops.

Specific Indications.—Determination of blood to the brain, flushed face and oft-recurring headache; paroxysms of tearing, rending neuralgic or rheumatic pains; weak, irregular heart-action, with cardiac hypertrophy, valvular insufficiency and shortness of breath.

Action and Therapy.—Viscum has toxic properties. Vomiting and bloody and tenesmic catharsis, prostration, contraction of the pupils, muscular spasm, convulsions and coma have been reported from eating the plant and berries. Its action would suggest its possible value in nervous disorders, and it has been used like strychnine in heart disorders with feeble pulse, dyspnea, edema, and inability to lie down. It is also asserted to possess parturient properties, but they do not compare with those of ergot, and the drug is almost never used for these purposes. It should be reserved for the conditions mentioned under "Specific Indications", and even in these it needs further study.

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