Leuce is an Oceanid Nymph that was abducted by Hades, then later on got turned into a white poplar in the Underworld. Her symbol is the white poplar, and Heracles went to the Underworld and usually makes a wreath from it. She was abducted because she was also another lover of Hades, and Hades pretended that he didn't know her, so he turned her into a plant without mercy.
Leuce's official Greek name is Λευκη.
Leuce holds a grudge against Hades, ever since he turned her into a plant, and she thought that their relationship actually had potential.