Answer:
sunflower is used here to symbolise a traveler on this earth and sun is used to symbolise the light and brightness.
Explanation:
The traveler is tired of his journey on the Earth and is looking for eternity or sweet golden clime where there is brightness and light. His journey is done once he has attained this higher plane of existence. This is just like a sunflower that follows the movement of the Sun across the Sky to get light in order to turn into a flower.