Like the bees, once the temperature gets to 50 degrees and above my husband and I are outside on the move. Its not hard to notice the changes in the view from morning to evening when you spend nearly 80 percent of your time in nature like we do. In the morning the wild flowers are on display, bringing life and a multitude color to a mountain landscape but in the evening the once vibrant petals close and shades of green take over.
Have these flowers become sleepy and fallen into a slumber and if they’re not sleeping, why have they closed for the night?
The truth is flowers never tire like we humans do, they are exhibiting a natural behavior known as nyctinasty. Nyctinasty is a mechanism that causes plant movements in response to the day-night cycle or temperature changes. Plants perform this movement for a variety of reasons. Some flowers save their nectar from nighttime nectar thieves like bats and moths by closing their flowers, some perform this process to prevent pollen from becoming wet and heavy with dew helping pollinators transfer more easily dry pollen and increasing success or reproduce, while other plants close up to protect themselves from nighttime chill. Wildflowers, Annuals, perennials, vegetables and more take action as the sun begins to set.
Wildflowers like the daisy, dandelion and chicory draw in their flower petals as the sun moves across the sky into evening leaving just their leaves at attention.
Annual plants hurry through their life cycle in just one year, which means that they have a limited opportunity to attract daytime pollinators. Some save their pollen and nectar by closing in the dark and opening when the sun rises to attract butterflies, which are daytime pollinators. The common chickweed in response to the setting sun folds up its leaf tips in addition to closing its flowers. Others you may see closing in for the night are Oxalis, Gazania and Morning Glory.
A number of perennial plants will also fold up their flowers and sometimes their leaves to protect themselves from nighttime nectar collectors and to save their flowers from harsh environmental conditions. The purple winecup flower opens in the morning and closes at night, but the blossoms stay closed once the flower is pollinated. The white daisy’s petals surround yellow centers and close as evening falls and so do the tulip and crocus.
The legume or pea family has many members including beans and alfalfa which all close up their leaves and flowers at night.
Some shrubs and trees also possess the ability to close their flowers and leaves. One of them being the Rose-of-Sharon. This 8-foot-tall shrub closes its blossoms at night and open with the rising sun. The evergreen magnolia blossoms open in the morning and close at night for two or three days before dying.
Even some water plants close their flowers at night including the “sacred” lotus and the American white waterlily. These surface floating flowers close in the afternoon and throughout the night and open again in the early morning.
All around the Adirondacks plants of all kinds have found their way to protect themselves, promote the survival of their species and shelter themselves from the elements. If you’re out for the day, take notice of what is open and what closes during the evening. You might be surprised to find how much of the flora has appeared to have fallen into a slumber when in fact they are just reacting to the call of nature.
Chicory flower by Forest Wander from Cross Lanes, USA, CC BY-SA 3.0, via Wikimedia Commons. Photo at top by Jackie Woodcock