Acalypha virginica.

Botanical name: 

ACALYPHA VIRGINICA, L. Mercury weed. Common from Canada to Florida. Elliot says that Dr. Atkins has found it expectorant and diuretic, useful in humid asthma, ascites, and anasarca. The empirics of the South use it for many other purposes. This plant deserves investigation; the other species of the genus have probably similar properties.

Medical Flora, or Manual of the Medical Botany of the United States of North America, Vol. 2, 1830, was written by C. S. Rafinesque.