Lemon balm (Melissa officinalis) is a soft, lemon-scented herb of the mint family, its crinkled heart-shaped leaves giving off a gentle citrus-and-honey fragrance when bruised. Used fresh in teas, salads, fruit dishes and desserts, it is best known as a soothing, nerve-calming herb — the classic ingredient of carmelite water and a mainstay of the cottage tea garden.