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 appearance bee blue-sky brown flowers gold golden insect large-head light plant plants radiant sky spiralling-florets sunflowers sunlight sunny sunshine bud composite-flower dwarf-sunflower green Helianthus unopened black budding distinct distinctive furry garden