Dancing Plant

I have just read a news which was about a kind of dancing plant they claimed it was discovered in Southeast China. Then I started to find the relevent news in google in English, and here it is, the dancing plant where first discovered by Darwin in 1855. An article about this plant can be found here and there is another article tells a more detailed story.

It is interesting that I didn't know a plant can dance and I somehow a little bit ashamed of myself as I studied biology in my under.

This dancing plant is certainly dance with sound waves according to the posts. I wonder how it dances and how fast it can move in its motion. It is really a intriguing question "Why does a plant respond to sound waves and how?".

This plant is named "Desmodium gyrans". I guess the last word has a gyr- prefix in its name becuase it moves somehow clockwise and anti-clockwise in its dancing behavior.

If anyone has seen this kind of plant could you please tell me more about it. I would like to hear your description. Thanks.