I read today that “Campaigners in Japan are asking people to grow sunflowers said to help decontaminate radioactive soil, in response to the Fukushima nuclear disaster that followed March’s massive quake and tsunami.” What a hopeful, practical and wonderful gesture towards a happier, healthier Japan.
According to SunflowerGuide.com “The default direction of the sunflower head is to point east towards sunrise (the location of the sun when it rises over the horizon in the morning.) During the day motor cells in the sunflower stem tilt the flower bud to try to receive a maximum amount of sunlight. By evening, the sunflower head is pointing west, towards sunset (the location of the sun on the horizon just before it is no longer visible.) This causes the sunflower to basically trace a 180 degree arc, tracking the sun’s position throughout the day, from horizon to horizon, sunrise to sunset.
Overnight, the sunflower will reset to its original eastward positioning and wait for the morning, ready to follow the sun’s path once again.
Once blooming however, sunflowers no longer exhibit heliotropic behaviour, and the stem is generally frozen into an eastward-facing position.” Fascinating!