As a young child, I remember coming across a plant that really amazed me. I was walking to the bus stand, on the way to school one morning. I happened to brush against this plant. As I touched the plant, the leaves of the plant moved! I was shocked — plants cannot move, I told myself. I remember sitting down on the road and touching another leaf on the plant, and watching the plant move again! I was so amazed that I almost missed my school bus that day!
Now I am grown up, but my fascination with this plant called Chui-mui or Touch-me-not (Mimosa pudica) remains! So what if I am almost 50 years old! Just this morning, I spotted flowering Chui-mui plants (also called Tottalvade in Tamil) along the road. The plant is easy to recognise because of its small pink ball-like flowers. The plant has small, oblong leaves. These small leaves are arranged on four leaflets, at the tip of a stem. Once again, I sat down on the road (I had no school bus to catch this time, so I did not need to hurry!). I pressed the entire leaf with my hand, and immediately, all the four leaflets closed and collapsed. It was as though the plant quickly closed its ‘eyes’, saying-don’t touch me! I watched the leaf closely. After two minutes, some leaves started opening again, slowly. It seemed to me that the plant was slowly opening its ‘eyes’ to check whether there was any danger. In four minutes, the leaf was completely open again!
I moved to another part of the plant. This time I was more gentle and I touched only one small leaf. To my surprise, only this single leaf closed up, while the rest remained open. Then, I touch the leaves on one side of the leaflet.
This time, all the leaves on the left side closed, while the leaves on the right side remained open! After all this activity, I decided to stop “playing” with the plant. I was curious — how and why does the plant behave like this. I found out that all plants use water pressure to stay erect. The Chui-mui plant, when touched, selectively reduces the water pressure causing the leaf or leaves to collapse. It is believed that this sudden motion scares off grazing animals (and humans!) who get startled by the quick movement of the plant.
The Touch-me-not plant grows throughout India along roadsides, flowering in monsoon months. So step out and go look for the Touch-me-not plant. Touch its leaves and experience the thrill of watching a ‘moving’ plant!
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