Why Sunflowers Follow The Sun; Here's What Studies Say
Science often baffles us in so many ways. Whether it’s naturally occurring chemical reactions, bizarre facts about flora and fauna or exceptions in the ecosystem, every single day we come across discoveries. One such phenomenon that has always fascinated human beings is the ability of the sunflower plant to respond to the sun and turn in its direction. As much as it is delightful to see it happen, do you know what causes the sunflowers to turn towards the sun?
According to an article published by npr.org, a 2016 research suggested that the young plant’s sun-tracking can be explained by circadian rhythms. The ability to track the sun is known as heliotropism and the circadian rhythm refers to the behavioural changes tied to an internal clock that we humans also have.
UC Davis Professor and study co-author Stacey Harmer, back then, said, “It’s the first example of a plant’s clock modulating growth in a natural environment and having real repercussions for the plant.”
It was revealed that the plant’s stems grow unevenly during the day and night, making it seem like the plant is moving according to the sun. Here is the animation to help you understand:
It was seen during the research that the stem’s growth on the east side was higher during the day and very low at night and the west side was following the pattern.
Mature sunflowers respond differently to the sun. As the overall plant growth slows down, the circadian clock makes sure that the plant reacts more strongly to light early in the morning than at other times of the day. Therefore, the plant faces east the whole day and stops moving westward during the day.
Researchers also compared mature flowers facing east with those facing west. They found out that east-facing flowers attracted five times as many helpful pollinators.