Yesterday, we noticed this chorus beaming at its conductor. We think that these are Heliopsis, one of the many members of the sunflower family. We’ve always wondered how young sunflowers “worship” the sun, and these cheery things inspired us to go to the books. They awake in the morning facing east, awaiting the sun; when the sun rises, they track it, slowly turning west as the earth turns. At night, they slowly turn back to gaze east again, ready for dawn.
It seems that this process (“Heliotropism”) occurs because the plants have a circadian rhythm (think internal clock) that awakens an unusual growth pattern in the flowers’ stems: during the day: growth on their east sides is faster than on their west sides; during the night, the process is reversed. This allows the young plants to grow as they turn toward the sun and to return to their original orientation after sundown. Mature plants usually maintain a steady gaze to the east. (Brooklin, Maine)