French sorrel (Rumex scutatus), also called buckler sorrel and shield-leaf sorrel, is a plant in the buckwheat family, used as a culinary herb.
As a culinary herb, it is used in salads, soups, and sauces (especially for fish). French sorrel tastes tart from its oxalic acid content, with a hint of lemon. Later in the season, it can be bitter.