An orange born in Huainan is an orange, and an orange born in Huaibei is an orange.

It means that oranges grown in the south of Huaihe River are delicious oranges, while oranges grown in the north of Huaihe River become inedible oranges.

The orange in Huainan is orange, and the orange in Huaibei is orange, which is a story in primary school Chinese textbooks. It is said that at the end of the Spring and Autumn Period, the doctor of the State of Qi went to the State of Chu. Relying on the strength of the State of Chu, the King of Chu insulted his country several times, but also solved the crisis again and again with wit and eloquence, and saved the dignity of him and the State of Qi! The bridge of "Huainan orange gives birth to orange, Huaibei orange gives birth to bitter orange" has been spread for thousands of years.

As an economic tree species, citrus is mainly produced in central and southern areas such as Zhejiang, Fujian, Hunan, Sichuan, Guangxi, Hubei, Guangdong, Jiangxi, Chongqing, Taiwan Province Province, and less distributed in the north. The main reason is that the temperature required for citrus growth and development is between 12.5 ~ 37℃, and the soil pH is between 5.5 ~ 6.5, which are just met in the south-central region, so they are distributed in the south-central region.