In China, it was first born in Xinjiang, which was called the Western Regions in ancient times, and was introduced to the mainland after Zhang Qian went to the Western Regions. In ancient China, the ethnic minorities in the north and west were called "Hu people", so they were originally called "walnuts".

Also, a friend on the second floor said that Zhang Qian's "digging through" the western regions may be a slip of the pen. "Depression" means that there was no road, and Zhang Qian was the first to open the passage. See Han Shu Da Wan Zhuan.