Here is a whopper sunflower in my garden. I thought I would give you some information about them; went to Wikipedia and my eyes quickly began to glaze over and when I got to the mathematics of sunflowers, I checked out. I did glean a few tidbits FYI.
Sunflowers are native to the Americas. The Spaniard conquerors tried to suppress cultivation of it because of its association with solar religion and warfare. Native Americans planted sunflowers on the north edges of their gardens as a "fourth sister" to the better known three sisters combination of corn, beans and squash. The Russians used sunflowers to extract toxic ingredients and metals from the soil after the Chernobyl disaster.
But in my little corner of the world, the heads face east at sunrise every morning and over the course of the day, follow the sun from east to west. I love that. The squirrels will get mine before I do. Nevertheless, I still eat raw unsalted sunflower seeds on my Cheerios every morning.