The corolla of a sunflower is composed of hundreds of small flowers, and the surrounding small flowers are different in structure and function from the small flowers near the center. When insect pollinators move through the inflorescence, they pollinate hundreds of small flowers in the process.
Scientists have discovered that the order of the florets in the inflorescence is not random, but a regular spiral. The number follows the Fibonacci sequence in mathematics: 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144... Recently, scientists have checked the growth points of sunflowers at the molecular level for the first time. Or how the meristem forms a spiral. With the help of X-ray tomography, they scanned three-dimensional images of different developmental stages of meristems. They used a confocal microscope to examine meristems smaller than one millimeter to determine the location of the plant hormone auxin, which determines the location of the growth point.
During the growth process, the auxin levels in multiple parts of the meristem rose to the maximum at the same time. The new auxin maximum point always forms and moves between two adjacent maximums. The number of clustered spots formed by auxin increases rapidly as the diameter of the meristem increases, and the law follows Fibonacci Number: The next number is always the sum of the first two numbers. This is why even in meristems that are not completely symmetrical, the spiral is regular.
