Also known as the Blue Dawn Flower and one of September's birth flowers, the morning glory is sensitive to atmospheric changes and can be read as a harbinger of changing weather. Morning glories shut their petals before a rain and open up for fine weather. As its name suggests, the morning glory blossoms unfurl in the morning hours to greet the sun and then close later in the day as the sun gets hot; by evening, when temperatures are cooler, the blooms tightly close. They are exceedingly rapid climbers, and the twining stem can complete a circle in two hours, turning against the sun, or just contrary to the hands of a watch. It will smother huge trees and cover huge ravines. In rural England the plant was called the "life of man" because it was thought to illustrate in a day the stages of human life: childhood in bud form in the early morning, maturity in the fully opened blossom at midday, and old age and death as the flower wilts in the evening.