A wrist corsage is worn on the left wrist. Traditionally, boutonnières and corsages are worn on the left side of the body because that way the flowers are closer to the heart.
A corsage is a small bouquet of flowers worn on a woman's dress or around her wrist for a formal occasion, traditionally purchased by the woman's date. Corsages are most frequently worn to school dances, most popularly the prom. It is common practice for a young man to present his prom date with a wrist corsage at the beginning of the night and to wear a matching boutonnière on his lapel.