The little green plant known as wood sorrel (Oxalis stricta) has often been mistaken as clover because of its three leaflets. On closer examination, you'll find a big difference. Sorrel's leaflets are heart shaped, while clover leaflets are round or oval. Wood sorrel grows in both sunny places and shady spots on the edges of woods throughout the eastern U.S., and it has many relatives growing coast to coast. Wood sorrel usually tops out at under a foot tall, and it typically has small yellow flowers, though some species have more pinkish or purplish blooms. Looking much like a classic shamrock, the fresh leaves can be eaten raw as a tasty sour salad green.