Sunflowers have either 34, 55 or 89 petals on their face, depending upon the size of the sunflower. This number is based from the Fibonacci number and flower patterns. Fibonacci numbers are based on a certain sequence.
The number of spirals in the center of a sunflower corresponds to a specific Fibonacci number. The head of the sunflower is made up of small seeds that are produced at its center and then migrate towards the outside of the flower. Each seed appears at a specific angle in relation to the one that came before it.
The petals of the sunflower are formed at the extremity of one of the seeds at the edge of the spiral. This is the reason the petals correspond with a Fibonacci number.