Blessed thistle is a plant in the aster family that is native to the Mediterranean region. The herb was widely cultivated in Medieval monastery gardens after King Charlemagne was visited by an angel. According to the legend, the king was instructed to fire an arrow into the air and whichever plant it came to rest upon was the one he should give to his soldiers who had the misfortune of contracting the plague. Whether or not the king took aim at the stand of thistle where the arrow landed is not known, but this is why the plant become “blessed.”