Prayer plants (Maranta leuconeura) have long been a favorite of those who grow houseplants.

My college days are full of memories and overwhelmingly, most of them are good ones. As is the case with most people, I experienced a lot of things for the first time, including growing houseplants. I’m not sure what made me want to undertake this endeavor, but I went to Frank’s Nursery & Crafts on Coliseum Boulevard and purchased some.

Not having grown any previously, I picked one of the easiest, a philodendron. But another caught my eye for a number of reasons. There it sat, in all its spotted leaf glory, with an intriguing name – prayer plant. I went home to my apartment with one of those too, because who can’t use a little prayer in their lives?

The prayer plant is one whose leaves move upward on their stems as darkness approaches, resembling hands in prayer. In the morning, when the sun rises and daylight breaks, the leaves splay out again for the day. Maranta leuconeura is just one of several plants that respond to the environment by closing when it becomes dark. Some have flowers that close at night and others have leaves that fold up. This is similar to a circadian rhythm and is called a diurnal rhythm.

A study in England, whose results were just released in 2018, found that a plant’s ability to adjust to its environment in this way is related to the sugars produced during photosynthesis. This process varies in intensity during the day and night. The plant is constantly measuring the amount of sugars it contains and adjusts its behavior according to that level.

If you’ve ever grown a prayer plant, you know that it reliably follows this daily pattern, but there are others. You’ll mostly notice it in flowers which are fully open on a sunny day, but only partially open on cloudy ones and close completely at night. This behavior is called nyctinasty.

Morning glories are so named because they open fully in the morning and gradually close up as the day moves into evening. Others that display this behavior are California poppies, gazanias, ice plants (Delosperma sp.), tulips, crocus, Rose of Sharon, and African daisies (Osteospermum sp.) Many legumes, such as beans, peas and clover fold their leaves up at night.

Conversely, there are plants which only bloom at night, such as moonflowers and four o’clocks. As you might guess, these flowers are pollinated by insects that are most active at night, mostly moths. The night-blooming cereus cactus famously blooms at night and its bloom only lasts for that one night.

People are affected by light too, and we pattern our behavior according to day and night, although not everyone does this in the same way. Natural energy levels in humans can vary enough that they’ve earned the nicknames of night owl and morning lark. I will never be a lark. How about you?