Longan (Nhan)

There are many varieties of longans. The most renowned variety of longan is the cage longan of Hung Yen Province. There are varieties that have a thick pulp and a very sweet taste called pulp longan. Water longans have a thin watery pulp and a fresh sweet taste. In the South, there is the longan of Chau Thanh (Dong Thap Province), which is fairly renowned. This variety has a watery pulp, a very sweet taste, a perfumed scent, and small black seeds, which is why it is called nhan tieu (pepper grain longan). 
                           

The longan is a tropical fruit rich in nutrients. It is used in the preparation of sweet lotus seed soups. A longan that has been rid of its black kernel then dried over a fire is called long nhan (literally: dragon’s eyes); it is one of the tonics used in the recipes of traditional medicine.

Source TCDLVN