Because fruits could not be stored in the past, which was not conducive to transportation, longan was always dried before being transported to the north. Because longan is produced in Guangxi (Guangxi) and is round, northerners call it longan. (I don't know if it was taboo to say dragon in feudal times, so it can't be called longan, so the official name (North) is also called longan), so they don't know that the original form of longan is longan.

Later, fruits can be stored and transported conveniently. Longan was transported to the north as a fruit, but northerners never touched it, only touched its mummy "Longan", so Longan is also called Longan.

So there are many longan in the south, and there are many longan in the central plains and the north.