Rue was once called the "Herb of Grace" and was included along with garlic in the "Vinegar of the Four Thieves" during the plague. Rue was once an officially recognized treatment for hypertension, diabetes, and allergic reactions. It's primary reputation is that of an anti-spasmodic to smooth muscles. It is still a popular folk medicine in countries like Mexico, Lebanon, Iran, India and China. In traditional Chinese medicine, the leaves are applied to reduce inflammation from snakebites, insect bites, strain, and sprains. Used after Arnica has been tried. Not to be used during pregnancy, as it is uterine stimulant. It can cause contact dermatitis after handling the fresh plant. Hardy to zone 4.