Sunflower Secrets Unveiled
Caleb Ryan
| 14-05-2024
· Plant Team
When it comes to sunflowers, what comes to your mind first? Sunflower seeds or sunflowers turning towards the sun?
In fact, the secrets of sunflowers are far more than just these.
Today, let's uncover the mysteries of sunflowers together!
Sunflower is a familiar plant, it is a large annual herbaceous plant. It has a wide range of uses, grows rapidly, and is easy to cultivate, being planted all over the world. Sunflower seeds have extremely high oil content, they are delicious when roasted, and can also be pressed for oil, making them an important oil crop. Its flower heads, stems, husks, etc., can be used as industrial raw materials...
Whether sunflowers face the sun depends on what stage of growth they are in. Saying sunflowers "often face the sun" like a reference book is inaccurate.
During the period from germination to the full bloom of the flower head, sunflowers do indeed face the sun, with their leaves and flower heads following the sun from east to west during the day.
However, it's not an immediate follow-up. Botanists have measured that the direction of the flower head lags behind the sun by about 12 degrees or 48 minutes. After the sun sets, the sunflower's flower head slowly swings back, and around 3 a.m., it faces east again, waiting for the sun to rise. However, once the flower head blooms, it no longer rotates with the sun but remains fixed facing eastward.
Why eastward
The reason sunflower leaves and flower heads can turn towards the sun is that, under sunlight, the auxin content on the shaded side of the sunflower increases, stimulating the elongation of cells on the shaded side, gradually causing it to turn toward the sun. After the sun sets, auxin redistributes, causing the sunflower to slowly turn back to its starting position, which is eastward.
After the flower head blooms, the sunflower stops growing and fixes the flower head facing eastward. Why do sunflowers face eastward instead of another direction or upwards? This may be the result of natural selection, beneficial for the reproduction of sunflowers.
Sunflower pollen is sensitive to high temperatures. If the temperature exceeds 30 degrees Celsius, it will be scorched. Therefore, facing eastward can avoid direct sunlight at noon and reduce radiation.
However, the flower head is exposed to sunlight early in the morning, which helps dry the dew condensed at night, reducing the possibility of fungal attack. Moreover, on cold mornings, under the sunlight, the sunflower's flower head becomes a warm nest, attracting insects to stay there and help with pollination.
Sunflowers contain mathematical patterns
The arrangement of flowers and seeds in the sunflower head is not random; it contains mathematical patterns.
In the center of the sunflower head, the tubular flowers and seeds radiate outward, with the number in each circle being 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144..., arranged according to the Fibonacci sequence, where each number is the sum of the two preceding ones.
This arrangement maximizes the number of seeds that can be accommodated in the same area, aiding in the propagation of more offspring.
In sunflowers, we see the wonders of nature and the adaptation and evolution of life to the environment. Sunflowers, likewise mentors, silently convey our teachings about survival, adaptation, and beauty. Perhaps, in these subtle details, we can more deeply feel the mysteries of nature and the preciousness of life.