What Flowers Close at Night and Why Do They Dream of the Moon?

What Flowers Close at Night and Why Do They Dream of the Moon?

The natural world is full of mysteries, and one of the most enchanting is the behavior of flowers that close their petals at night. This phenomenon, known as nyctinasty, has fascinated botanists, poets, and gardeners alike for centuries. But what drives these flowers to fold up as the sun sets, and what secrets do they hold in their nocturnal slumber? In this article, we will explore the science behind this behavior, the cultural significance of night-closing flowers, and the poetic interpretations that have emerged over time.

The Science of Nyctinasty

Nyctinasty is the term used to describe the rhythmic movement of plants in response to the onset of darkness. This behavior is most commonly observed in flowers, but it can also be seen in some leaves and other plant parts. The mechanism behind nyctinasty is complex and involves a combination of hormonal changes, turgor pressure, and circadian rhythms.

Hormonal Changes

One of the key players in nyctinasty is the plant hormone auxin. Auxin is responsible for regulating growth and development in plants, and it plays a crucial role in the opening and closing of flowers. As daylight fades, the levels of auxin in the plant decrease, causing the cells in the petals to lose turgor pressure. This loss of pressure leads to the folding or closing of the petals.

Turgor Pressure

Turgor pressure is the force exerted by the fluid inside plant cells against the cell walls. When turgor pressure is high, the cells are rigid and the petals are open. When turgor pressure decreases, the cells become flaccid, causing the petals to close. This process is similar to how a balloon deflates when the air is let out.

Circadian Rhythms

Circadian rhythms are internal biological clocks that regulate various physiological processes in plants and animals. In the case of nyctinastic flowers, the circadian rhythm helps to synchronize the opening and closing of the petals with the daily cycle of light and darkness. This ensures that the flowers are open during the day when pollinators are active and closed at night when they are not.

Cultural Significance of Night-Closing Flowers

Throughout history, night-closing flowers have held a special place in human culture. They have been used as symbols in literature, art, and religion, and they have inspired countless myths and legends.

Symbolism in Literature and Art

In literature, night-closing flowers are often used as symbols of mystery, secrecy, and the passage of time. For example, in Shakespeare’s “A Midsummer Night’s Dream,” the flower called “love-in-idleness” is said to have the power to make people fall in love. This flower is believed to be based on the real-life night-closing flower, the pansy.

In art, night-closing flowers are often depicted as symbols of the ephemeral nature of beauty. The Dutch still-life painters of the 17th century, for example, frequently included night-closing flowers in their compositions to remind viewers of the fleeting nature of life.

Religious and Mythological Significance

In many cultures, night-closing flowers are associated with the divine and the supernatural. In ancient Greek mythology, the night-blooming cereus, a type of cactus that opens its flowers only at night, was said to be a gift from the moon goddess Selene. In Hinduism, the night-blooming jasmine is considered sacred and is often used in religious ceremonies.

Folklore and Superstitions

Night-closing flowers have also been the subject of various folk beliefs and superstitions. In some cultures, it is believed that picking a night-closing flower after dark will bring bad luck. In others, these flowers are thought to have magical properties, such as the ability to ward off evil spirits or to bring good fortune.

Poetic Interpretations of Night-Closing Flowers

The behavior of night-closing flowers has inspired poets for centuries. These flowers are often used as metaphors for human emotions and experiences, such as love, loss, and the passage of time.

Love and Longing

In many poems, night-closing flowers are used to symbolize the intensity of love and longing. The idea that these flowers close their petals at night, only to open them again in the morning, is often seen as a metaphor for the cyclical nature of love. For example, in the poem “The Night-Bloming Cereus” by Harriet Monroe, the flower is described as a symbol of unrequited love:

“She blooms but once, and then she dies, And all her beauty fades away; But in her brief and glorious hour, She holds the night in her sway.”

Loss and Mourning

Night-closing flowers are also used to symbolize loss and mourning. The idea that these flowers close their petals at night, as if in mourning for the passing of the day, is a powerful metaphor for the experience of grief. In the poem “The Pansy” by Emily Dickinson, the flower is used to symbolize the pain of losing a loved one:

“The Pansy at my feet Doth the same tale repeat: Whose are the little feet, Whose are the little hands, That lie beneath the sands?”

The Passage of Time

Finally, night-closing flowers are often used to symbolize the passage of time. The idea that these flowers open and close with the rising and setting of the sun is a powerful reminder of the fleeting nature of life. In the poem “To the Evening Star” by William Blake, the evening star is compared to a night-closing flower:

“Thou fair-hair’d angel of the evening, Now, whilst the sun rests on the mountains, light Thy bright torch of love; thy radiant crown Put on, and smile upon our evening bed!”

Conclusion

The behavior of night-closing flowers is a fascinating example of the intricate relationship between plants and their environment. From the scientific mechanisms that drive nyctinasty to the cultural and poetic interpretations that have emerged over time, these flowers continue to captivate our imaginations. Whether they are seen as symbols of love, loss, or the passage of time, night-closing flowers remind us of the beauty and mystery of the natural world.

Q1: Why do some flowers close at night?

A1: Some flowers close at night due to a phenomenon called nyctinasty, which is driven by hormonal changes, turgor pressure, and circadian rhythms. This behavior helps protect the flowers from nocturnal predators and conserves energy.

Q2: What are some examples of night-closing flowers?

A2: Examples of night-closing flowers include the morning glory, tulip, crocus, and oxalis. These flowers typically open their petals during the day and close them at night.

Q3: Do all flowers close at night?

A3: No, not all flowers close at night. Some flowers, like the moonflower and night-blooming cereus, actually open their petals at night and close them during the day.

Q4: What is the cultural significance of night-closing flowers?

A4: Night-closing flowers have been used as symbols in literature, art, and religion. They often represent mystery, secrecy, and the passage of time, and have inspired various myths and legends.

Q5: How do circadian rhythms affect night-closing flowers?

A5: Circadian rhythms help synchronize the opening and closing of night-closing flowers with the daily cycle of light and darkness. This ensures that the flowers are open during the day when pollinators are active and closed at night when they are not.