Rumex scutatus
Rumex scutatus is a plant in the buckwheat family, used as a culinary herb. Its common names include French sorrel, buckler sorrel, shield-leaf sorrel, and sometimes the culinary name "green-sauce".
As a culinary herb, it is used mainly in salads. The flavour of French sorrel is slightly bitter or tangy, spiced with a hint of lemon; the sharp flavour is due to oxalic acid. French sorrel is hardy in most regions, tolerating frost, full sun and short dry spells. It grows quickly to a clump up to in diameter, with long leaves up to in width. It is sometimes preferred for culinary uses to Rumex acetosa, garden sorrel.