Gardeners' World Web User
28/11/2011 at 18:37
Apparently the Romain lettuce comes from when the Papal seat moved to Avignon, France. Although you will have to ask a historian why, however the locals picked up the habit of lettuce growing which was eaten by the clergy. The leaves being lightly cooked, which was healthier in the days of poor sanitation.
Perhaps another reason why this plant was used was the fact that the sap contains mild opium compounds so would dull the pain of any medieval teeth?