Why is Mimosa called Mimosa, and why do its leaves fold up when you touch them?

1. Why is it called Mimosa?

Mimosa gets its name mainly because its leaves are special. Once touched or raindrops fall on the leaves, the leaves will immediately shrink and the plant will droop slightly. Just like a shy little girl, when someone makes a joke to her, she immediately covers her face and blushes out of shyness, so it is named Mimosa.

2. Why do leaves fold up when touched?

The reason why mimosa folds its leaves is not just because it is really "shy", but because it has a special organ called the "pulvinus" at the base of its petiole. It contains many thin-walled cells, which are very sensitive to external stimuli. Once the leaf is touched, it is immediately transmitted back to the pulvinus. At this time, the cell sap of the thin-walled cells in the pulvinus will begin to flow into the intercellular spaces, reducing the cells' ability to expand. The pressure between the cells in the lower part of the pulvinus decreases, causing the leaves to close and the plant to droop. After a few minutes the leaves will slowly open again. Therefore, the fact that the leaves of mimosa close when you touch them is a physiological phenomenon.

3. Notes

Don't touch the leaves of the mimosa often. Frequent handling can cause them to develop poorly or even wither prematurely. Moreover, mimosa is slightly toxic. If you touch it frequently, it will affect the hair follicles in the human body and cause hair loss.