Sunflower Motion — More Complex than Thought

Sunflowers are one of the easiest flowers to identify, what with those big yellow heads loaded with sometimes 2,000 seeds and such. They are also a provision of the Creator for our benefit, grown and harvested for oil and the seeds, which are healthy — and may be a substitute for people with nut allergies.

Of course, a famous characteristic is how young sunflowers track the sun from east to west. It was thought that this was a kind of phototropism, which is when plants and fungi grow toward (or away from) a light source.

Sunflowers, Pixnio / Bruce Fritz

It has been learned that this ability of young sunflowers to follow the sun across the sky (even on cloudy days) is heliotropism. It is not fully understood and is very complex. Plants adapt to changes in conditions, and different genes are expressed in response to certain conditions. This is yet another example of the Master Engineer at work.

Botanists have long wondered how heliotropism works to allow this amazing plant to track the sun’s trajectory across the sky, always keeping its face pointed at the sun. Though initially assumed to be a kind of phototropism, scientists at the University of California, Davis discovered heliotropism is its own distinct mechanism that is far more complex and detailed, involving the activation of a large number of genes and possible genetic rewiring.

To read the entire (but short) article, visit "How Sunflowers 'See' the Sun."