When this flower blooms, it reminds you that it’s time for dinner.

Welcome to Northern Plants. Today I’m going to introduce you to Mirabilis jalapa .

Mirabilis jalapa has many different common names across the country, such as bath flower, dinner flower, landmine flower, etc. The first two names are because its flowers generally begin to bloom from four or five o'clock in the afternoon every day . In the past, at this time, every household would begin preparing dinner and boiling bath water.

Mirabilis jalapa is a plant of the genus Mirabilis in the family Mirabilis jalapa. It is not a close relative of the real jasmine , but like jasmine, it was originally introduced from abroad. Mirabilis jalapa is native to the tropical regions of South America and was introduced to China in the late Ming Dynasty. The Guang Qun Fang Pu during the reign of Emperor Kangxi of the Qing Dynasty quoted the content of the Ming Dynasty's Cao Hua Pu, saying that "Mirabilis jalapa is a herb that produces fruit in spring", which should be the earliest written record of the name "Mirabilis jalapa".

At first glance, the flowers of Mirabilis jalapa look nothing special. They have all the necessary structures, such as sepals, petals, stamens and pistils. At most, there are more colors, including red, yellow, white, purple, and some with dots and stripes.

Image taken from video

Image taken from video

But in fact, the petals you see are not petals, and the sepals are not sepals .

So... what are they? This starts with the basic structure of flowers. The flowers of plants are actually special branches. The pedicels and receptacles are the stems in the branches, and the sepals, petals, stamens, and pistils are the leaves on the stems.

Image taken from video

In a flower, there are often more than one sepal and petal. All the sepals are collectively called the calyx, and all the petals are collectively called the corolla . When the calyx and corolla are combined, they are called the perianth .

The perianth of flowers of most common plants can be clearly seen to be divided into two separate layers, namely the calyx and the corolla. However, Mirabilis jalapa is different. Its perianth has only one layer, and it is unclear whether this layer is the calyx or the corolla, so it cannot be further subdivided . Even the description in "Flora of China" only says "perianth".

Image taken from video

What are those green structures below the flower if not sepals? They are called involucres. They appear to have five pieces, but in fact there is only one piece, with the edges divided into five lobes .

Image taken from video

Each flower of Mirabilis jalapa only blooms for one night, attracting insects for pollination through its beautiful perianth and fragrant smell. If you are unlucky and no insects visit, it doesn't matter. You can see that its stamens and pistils are very close to each other and mature at about the same time, which are characteristics suitable for self-pollination .

Image taken from video

After pollination is completed, the perianth of the Mirabilis jalapa will close and will not open again after dawn the next day, focusing on producing fruits and seeds.

Image taken from video

The fruit of Mirabilis jalapa looks like a small black mine, hence the name "mine flower".

Image taken from video

The seeds of the Mirabilis jalapa fruit are rich in starch, and after grinding, they can be made into fine white powder, which was used as cosmetics in ancient times, just like the foundation today. The "Cao Hua Pu" says that "the seeds have white powder, which can be applied to the face." Even the "Dream of Red Mansions" has detailed descriptions of using Mirabilis jalapa powder as cosmetics.

Author: Wu Changyu

Review | Wang Kang, Director of the Science Museum of the National Botanical Garden

The video is produced by Science Popularization China-Creation Cultivation Program

Text content is organized according to the video

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