Poppies have long been a symbol of sleep thanks to the opium extracted from them. The are also a symbol of death because of the common red varieties. In Greek and Roman myths they were used as offerings to the dead. When featured on tombstones they are are sign of eternal sleep. In some classic mythology the red poppies are also a symbol of a promise of resurrection after death. The red-flowered corn poppy is used as a symbol of wartime remembrance. Poppies are sometimes an important flower in Puerto Rican weddings. In Chinese folklore poppies represent loyalty and faith between lovers. In Greek myth Demeter created the poppy so she could sleep.