Sunflowers exhibit heliotropsim, meaning that the flowers and/or leaves follow the sun throughout the day starting in the East in the morning, moving toward the West throughout the day, and then returning to the East at night.>
It is a native species to N and S America and was used by American Indians for an important, high-energy food source. Spanish explorers carried it with them to Europe in the 1500s. Russian agronomists were responsible for the first agricultural hybrids. These returned to the United States with Russian and German immigrants.
One of the most beneficial uses of sunflowers is in the removal of toxic waste from the environment. Utilizing an emerging technology called rhizofiltration, hydroponically grown plants are grown floating over water. Possessing extensive root systems, they are able to reach deep into sources of polluted water and extract large amounts of toxic metals, including uranium. Such a process has been utilized in the former Soviet Union to decontaminate water polluted as a result of the 1986 accident at the Chernobyl nuclear power plant. The roots of floating rafts of sunflowers were able to extract 95% of the radioactivity in the water caused by that accident.
The composition of the sunflower's florets itself is also rather fascinating and has been studied by mathematicians like Leonardo Fibonacci (a 13th Century Italian mathematician from Pisa, Tuscany*) and Greek mathematicians alike.
The sunflower's complex mathematical structure is based upon the famous "Golden ratio" (again, discovered by Fibonacci) where the growth rate of successive numbers gives a ratio which converges on1/2x (1+/5) = 1.618, known as the "Divine proportion" or "Golden section" of geometry and aesthetics in nature.
In simple terms this means that there can be 34 spirals in one direction and 55 in the other direction, or on some larger flowers can range from 89 to 144. The symmetry and logic of a sunflower's flower structure has astounded and fascinated artists and mathematicians alike and manages to cross many fields of science in one simple... flower.