Common Sorrel, Garden Sorrel, Dock, Spinach dock, Narrow-leaved Dock
Rumex acetosa
Sorrel has a slight lemon hint to its taste. It can be used in combination with other herbs for making stews, meat pies, and other savory dishes. It can also be eaten freshly picked from the garden for an ingredient in salads. Sometimes you can buy it in small quantities at produce and health food markets.
Look for fresh Sorrel in markets that offer fresh herbs in small batches.