If you guessed Sunflower, your correct!
It's actually a Sunflower with all it's petals gone and it's seeds exposed. I found the natural pattern of the seeds and their black and white shells to be incredibly beautiful. I hand picked out some of the seeds to form the heart shape. I had a field day taking pictures of this flower. The head of this particular Sunflower was about 12" in diameter, far bigger then my hand!
Here are some more shots I took of the Sunflowers in bloom in my yard.