It’s really terrible: Not everyone can collect nectar from this common little flower!

Welcome to Northern Plants. Today I’d like to introduce you to Cynanchum rostellatum .

The character "藦" in Luoluo was also written as "摩" without the grass radical in ancient times. The earliest known written record comes from the "Newly Revised Materia Medica" in the Tang Dynasty. Some people have researched and believed that the "芄(wán)兰" written in "The Book of Songs" also refers to Luoluo.

Radish. Copyrighted image from the gallery, no permission to reprint

Asclepias chinensis is a very common weed. Its vines can often be seen entwining and spreading in urban green spaces in the north. It also has a close relative called Cynanchum chinense. They look a bit similar. Both are vines with heart-shaped opposite leaves. If you break the stems and leaves, they will ooze white latex.

Image taken from video

It is not difficult to distinguish the two. The petioles and midribs of the leaves of the radish are often red, and the corolla is sometimes light pink and covered with hairs .

Radish. Copyrighted image from the gallery, no permission to reprint

The petiole of Radish. Picture taken from the video

The petioles and veins of the goose down vine are not red, and the corolla is pure white without any fluff.

Goose down rattan. Copyright image, no permission to reprint

Every summer when the flowers are in full bloom, you can always see some insects lying on the radix spathiphyllum, motionless. If you look closely, you will find that they are all dried corpses. You may guess that it is because radix spathiphyllum catches insects and eats them, just like sundews and pitcher plants. This is not the case, because radix spathiphyllum is completely "negligently killing insects".

Asclepiadaceae is a plant of the Asclepiadaceae subfamily, Apocynaceae family. In many species of this subfamily, the stamens and pistils in the flowers are fused together to form a special structure called a gable crown .

Image taken from video

Deep inside the gambol, there is sweet nectar. When insects suck nectar, they need to squeeze their mouthparts into the gambol through the gap on the gambol, and then pull it out with force after sucking the nectar. This insertion and pulling will take away the pollen.

Insects vary greatly in size. Strong species like bumblebees can just "pull their mouthparts out and leave" after sucking the nectar, and there's nothing wrong with that. Very small species like ants can just go in and suck the nectar, and leave after that, and there's nothing wrong with that. But some medium-sized insects don't have enough strength, and their mouthparts can get in but they can't pull them out , and they end up trapped on the flower and die.

Image taken from video

The flowers of the goose down vine also have a gynostemma structure, but its flowers are relatively small and less likely to trap insects, so dead insects are not often seen on the flowers.

After sacrificing the lives of some insects, the successfully pollinated radish will produce fruits. Its fruits usually grow in pairs and are shaped like two short goat horns. In the Ming Dynasty's "Herbal Medicine for Famine Relief", plants such as radish and goose down vines are simply called "goat horn seedlings", and their fruits are also commonly known as "mother-in-law needles", which means sewing kit.

Image taken from video

When these "sewing kits" mature, they will split open from the middle and release the seeds inside. Each seed is covered with long, silky hairs , which will scatter when the wind blows, carrying the seeds away and landing in distant lands to take root and sprout.

Image taken from video

The inside of the peel after the seeds are spread is very smooth, a bit like a ladle used to scoop rice or water, but it is too small and certainly cannot be used by humans. People in some places imagine it to be a ladle used by crows and call it "crow ladle".

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

The cover image and some images in this article are from the copyright library

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