annual bloom bright cluster composite flower flora florets flower helianthus annuus inflorescence kernels large large head pattern petals popular seeds spiral spiralling florets sunflower widespread yellow bee composite-flower helianthus-annuus insect large-head spiraling-florets appearance blue-sky brown flowers gold golden light plant plants radiant sky spiralling-florets sunflowers sunlight sunny sunshine bud dwarf-sunflower green Helianthus unopened black budding distinct distinctive furry