Blue vervain

In Egyptian mythology, vervain grew from the tears of Isis, goddess of fertility, as she grieved for her murdered brother-husband, Osiris.  A thousand years later, vervain entered  Christian mythology as the herb pressed into Christ's wounds to stanch his bleeding, hence its name herb-of-the-cross.

Hippocrates recommended vervain for fever and plague.  The court physician to Roman Emperor Theodosius the Great prescribed it for tumors of the throat (probably goiters). His fanciful prescription advised cutting vervain into two pieces, tying one around the patient's throat and hanging the other over a fire.  As the heat and smoke shriveled the hanging root, the tumor was supposed to shrink.

The Romans spread vervain throughout Europe, where it became especially popular among the Druids of pre-Christian England, who used it in magic spells, hence its name enchanter's herb.

During the Middle Ages, vervain became a popular acne remedy.  Those with pimples stood outside at night holding a handful of the herb wrapped in cloth over their pimples and the blemishes were supposed to disappear.

From acne, vervain evolved into a treatment for other skin problems.  Seventeenth-century herbalist Nicholas Culpeper wrote: "The leaves bruised, or the juice mixed with vinegar, does wonderfully cleanse the skin, and take away morphew (dandruff)."  Culpeper also recommended vervain to treat jaundice, gout, cough, wheezing, bleeding gums, shortness of breath, fever and kidney stones. 

European animal studies show vervain depresses heart rate, constricts the bronchial passages, and stimulates the intestine and uterus.  Because it may depress heart rate, anyone with congestive heart failure history or a history of heart disease should not use it.  The possibility of bronchial constriction might cause problems for asthmatics and those with other respiratory conditions.  Intestinal stimulation might aggravate chronic gastrointestinal conditions, for example, colitis.  And pregnant women should steer clear of vervain because of its possible effect on the uterus - except possibly at term and under the supervision of a physician to help induce labor.