Rock Reed, or Shi chang pu in Chinese, is a plant native to Asia that was once used to ward off evil spirits. Today, its most widespread use is medicinal since it induces calm and has benefits on concentration.

Indeed, Shi chang pu calms the mind to promote stillness and concentration. Its relaxing action acts on the memory and the brain to allow a better retention of information, hence the frequent use of this plant in Asia during exam periods.