Arnica is a member of the aster family, which contains many plants avoided by allergy sufferers. It is thought the name "arnica" originates from a Greek word meaning "sneezing." Arnica is often used in salves, ointments and other preparations for application to unbroken skin. Tinctures are another common preparation of arnica. For an herbal compress (fomentation), pour 1/4 cup of boiling water over 2 teaspoons of arnica and steep for 10 to 15 minutes, then strain. DO NOT use during pregnancy or on open/broken skin.