Clytia

A mortal princess in Greek mythology, daughter of Orchamus and sister of Leucothea, Leucothea loved Apollo, the sun god. Apollo disguised himself as Leucothea's mother to gain entrance to her chambers. Clytia ("famous"), jealous of her sister because she wanted Apollo for herself, told Orchamus the truth, betraying her sister's trust and confidence in her. Enraged, Orchamus ordered Leucothea buried alive. Apollo refused to forgive Clytia for betraying his beloved, and a grievous Clytia wilted and slowly died. Apollo changed her into an incense plant, either heliotrope or sunflower, which follows the sun every day.

Ovid IV, 206.