Also known as Holy Thistle, Marian, Holy Thistle, Our Lady's Thistle, and St. Mary's. Do not confuse this with Milk Thistle. Used as an appetite stimulant, to treat constipation and flatulence. Blessed Thistle tea is used for treating a variety of liver problems, such as hepatitis and jaundice. Blessed Thistle can lead to nausea and vomiting if taken in excess