Thomas902 wrote:
Facing of sunflower towards the sun is known as phototropic movement. This is due to presence of auxin, a growth hormone in the stem. ... The higher concentration of auxin in the shaded side causes that side to grow faster, resulting in a positive phototropic curvature. Note: this effect diminishes in mature plants that are not in a rapid growth phase.
On the day when the sun is absent i.e. cloudy sunflowers follow their in-built biological clock (natural circadian rhythm). Therefore, their direction remains unchanged throughout a cloudy or rainy day, compared to the other usual days.
Even more amazing is their flower's seed growth pastern... This pattern of seeds within a sunflower follows the Fibonacci sequence, or 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144...1 If you remember back to college math each number in the sequence is the sum of the previous two numbers. Sunflowers typically have 55 perfect spirals! How awesome is that!
thank you for sharing Kalina
Facing of sunflower towards the sun is known as ph... (
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Thank you for interesting info ,Thomas 902 Shang.