Common wood sorrel, Oxalis acetosella is a member of the Oxalidaceae (wood sorrel) family that is common in Europe and most of Asia. The common wood sorrel is sometimes referred to as a shamrock (due to its three-leaf clover-like motif) and given as as gift on St. Patrick's Day.
This plants tends to like shade and can be found on the verges of woodlands. It grows well in a shady spot in any garden. The plant's leaflets are made up by three heart-shaped leaves, folded through the middle. The stalk is red/brown, and during the night or when it rains both flowers and leaves contract
The plant has a sour taste (hence the name, which is derived from the French sur) and is high in oxalic acid which is slightly toxic and can interfere with digestion though. Use sparingly. Cooking, however, leaches-out the oxalic acid rendering the plant safer.