On my visit to Florida in June.... (yes I have let this go.... for a month), I saw some big yellow flowers that looked much like sunflowers.
But they did not grow on regular plants, nope these were growing on a tree. These flowers were way over my head and this was the best photo... I could get of the whole tree. It was a cloudy overcast (rainy) day and the sun was already getting low in the sky.
If I lived this far south I would have several of these in my yard....
edit-I did a little research on this plant and it may become invasive and spread in the yard. It is called the Mexican or Bolivian or Honduran Sunflower tree.