At Creation-Evolution Headlines, we learn (July 11, 2011):
Plants perform a wonder that has attracted the admiration of scholars from ancient Egypt, Greece and Rome to modern times: the ability to reproduce mathematically perfect patterns. This ability, called phyllotaxis, can be described mathematically with the Fibonacci Series and the Golden Angle. The beautiful spirals in sunflowers, artichokes, cacti, dandelion heads and other plants continue to fascinate children and adults today, but those are not the only examples. Leaves on a stem can emerge in phyllotactic patterns like a spiral staircase, and depending on the environment, plants can switch patterns at different stages in development.
In Current Biology, French biologists Jean-Christophe Palauqui and Patrick Laufs recounted some of the theories that have tried to explain phyllotaxis. More.
Plants have a built-in mechanism for arranging themselves, based on math, so what does that tell you? That math is a human construct?