Valentine 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.
The heart symbol could also be considered to depict features of the human female body, such as the female's buttocks, pubic mound, or spread vulva. The tantric symbol of the "Yoni" is another example of a heart-shaped abstraction of a woman's vulva. An early form of the heart symbol is derived from plants. The ivy leaf was used as mere decoration in the old days of oriental cultures, where it showed up on amphorae and other painted ceramics since 3000 B.C Adopted by the Greeks and later by the Etruscans and Romans, it entered European culture. The heart symbol was promoted widely by the Sacred Heart cult starting in the Middle Ages.
Inverted heart symbols have been used in heraldry as stylized testicles (coglioni in Italian) as in the canting arms of the Colleonis of Milan.