Causes of vibration when touching the branches of Lagerstroemia speciosa.

The wood of Lagerstroemia indica is hard, the biggest feature is that the roots and tips of branches are almost as thick, which is different from the characteristics of thick under the trunk, that is to say, the upper part of Lagerstroemia indica is heavier than ordinary trees, which determines that it is easy to shake. When we scratch its branches with our fingers, the vibration caused by friction is easily transmitted to more parts of the branches through hard wood, so it is easy to swing.

In fact, no tree is really ticklish, and the phloem of a tree has no sensory cells like animal skin. It is interesting to imagine the tremor of Ziwei when she is ticklish.