A close inspection of the huge blossoms rsp. the ripe seeds of sunflowers reveals two striking facts: One is, that the seeds form a peculiar spiral-shaped pattern: Two spiral vortices overlap each other. One vortex turns clockwise, the other one turns counterclockwise.
The second discovery requires a very focused examination, determining, how many single spirals are forming the two vortices. It can be concluded that the two spiral vortex are constructed of a different number of single spirals. They increase in the course of the size growth of the bloom basket, coming to a maximum of individual spirals once the ripening of seeds is completed.
By the way: In most cases, there are 21 single spirals in one direction and 34 single spirals in the other direction. With larger sunflowers even 34 and 55 single spirals can be counted. Do those numbers look somewhat familiar?