Family: Polygonaceae • Common: Common Sorrel; Common sorrel is today used in sauces and as a spinach or salad leaf; the sap can be used as a laundry stain-remover. Rumex acetosa; Garden Sorrel; Narrow-Leaved Dock; Spinach Dock; also known as common sorrel; is a herbaceous plant native to the British Isles. It was once cultivated as a vegetable but is now merely a wild food plant; it is also used in herbal medicine for its diuretic properties.