What fruit is Xiangyuan?

It is a traditional Chinese medicine fruit, also known as citron or citron seed, a rutaceae plant, with small fruit, yellow spherical or pear-shaped, colorless pulp, somewhat similar to grapefruit. It is widely used as a greening tree species in Taiwan Province, Fujian, Guangdong, Guangxi, Yunnan and other places, and has a very long planting history in China.