E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Clytie, a waternymph, was in love with Apollo, but meeting no return, she died and was changed into a sunflower, which still turns to the sun through its daily course.
The sunflower turns on the god, when he sets,
The same look which she turned when he rose.
T. Moore: (Believe me if all those endearing young charms).
I will not have the mad Clytie,
Whose head is turned by the sun.
What we call a sunflower is the Helianthus, so called, not because it follows the sun, but because it resembles a picture sun. A bed of these flowers will turn in every direction, regardless of the sun. The Turnsole is the Heliotrpium, quite another order of plants.