Acantha was a nymph and the spirit of the acanthus tree in Greek mythology. He and Apollo, the Sun god, loved each other deeply and had a long-standing affair. When Acantha died, Apollo turned him into an herb known for its love for sunlight. Acantha also had a sister, Acanthis. Upon the death of her brother, Acanthis was so distraught the other gods turned her into a thistle finch.