Oxalis tetraphylla (often still traded under its syn. O. deppei) is a bulbous plant from Mexico. A common name is “Iron Cross”, after a famous cultivar; it is also known as “lucky clover”, and in a wild or feral state as Four-leaf Sorrel or, least ambiguously, Four-leaved Pink-sorrel.
It has leaves divided into four and has been called “lucky leaf” and even “four-leaf clover”, but it is not a true clover. Related to the Common Wood-sorrel (Oxalis acetosella), it is commonly used as an ornamental plant. It is also edible, the flowers and leaves having a sharp lemon flavor. However, since the oxalic acid in the plant can interfere with the absorption of certain nutrients in the body, especially calcium, too much can be harmful.