Persephone's Flowers

During Percy, Thalia, and Nico's adventure looking for the Sword of Hades Persephone gives them various flowers.

Tracking Flower
A special flower that resembles a carnation. It would always point in the direction of the thief. The petals of flower would die as he got closer to escaping the Underworld It finally die as he released the titan Iapetus.

Travel Rose
After completing the mission, Persephone gave each of the demigods a red rose that, when crushed, would return them land of the living. These were similar to Poseidon's Pearls.

Trivia

 * Both types of flower were seen in the Demigod Files story, The Sword of Hades.