Valentine Heart

As icon
In European traditional art and folklore, the heart symbol is drawn in a stylized shape. This shape is typically coloured red, suggesting both blood and, in many cultures, passion and strong emotion. The hearts have constituted, since the 15th century, one of the red suits in most playing card decks. The shape is particularly associated with romantic love; it is often seen on St. Valentine's Day cards, candy boxes, and similar popular culture artifacts as a symbol of romantic love.
What the traditional "heart shape" actually depicts is a matter of some controversy. It only vaguely resembles the human heart.
The seed of the silphium plant, used in ancient times as an herbal contraceptive, has been suggested as the source of the heart symbol.