Indochina dragonplum (Dracontomelon duperreanum) or Sau in Vietnamese forms Hanoi's streets with old big trees, unique among localities in Northern Vietnam that are home to this kind of tree. 

Phan Dinh Phung Street is famous for old big Indochina dragonplum trees, one of the most beautiful streets in Hanoi. Photo: Huy Pham/ The Hanoi Times

Hanoi is famous for this kind of tree not only for its presence on downtown streets but the dried fruit made by Hanoians.      

Story of Sau trees on the street

In Hanoi, Indochina dragonplum trees line many streets such as Dinh Tien Hoang, Le Thanh Tong, Hai Ba Trung, Tran Hung Dao, Le Hong Phong, Tran Phu, among others offering cool shade. Among the streets, Phan Dinh Phung Street has two rows of these trees on the sidewalks. In addition, the trees appear on many streets citywide.

Regarding the plant’s origin, the book “Dai Nam Nhat Thong Chi” or the Geography of the Unified Great Vietnam of the Nguyen Dynasty wrote: “The districts of Phu Ninh or today’s Phu Tho Province, Bat Bat or Ba Vi District in Hanoi and My Luong or Chuong My District, Hanoi and Luong Son District of Hoa Binh Province grew a lot of Sau trees”.

In the past, people in these areas believed that what ancestors left their descendants was not money but gardens of Sau - the plant that is “beneficial to hundreds of generations.”

For that reason, every family there lived on the cultivation of the trees and sold Sau fruits. In Oriental medicine, leaves, flowers, and fruits of Sau are medicines for a number of diseases.

Moreover, their leafy canopy makes the tree looks like a giant mushroom watching from afar. 

In every April, Sau leaves fall down and cover the sidewalks of Phan Dinh Phung Street. Photo: Duy Tai

When the French colonialists invaded Hanoi in 1883, French envoy Bonnal advocated the re-planning of the area of Hanoi under their occupation which is today Hoan Kiem District and part of Ba Dinh District.

In order to reduce the heat of summer, the local authority chose Indochina dragonplum for urban greenery. The first streets to grow these trees were those around Hoan Kiem Lake, which are today Le Phung Hieu, Le Thanh Tong, Ly Thai To, Ngo Quyen, and so on.

According to the data of Green Park JSC, during the subsidy period, Sau trees accounted for about one third of the total number of trees in the four central districts of Hai Ba Trung, Dong Da, Ba Dinh and Hoan Kiem.

Tree of Hanoians’ childhood

For many generations of Hanoians, Sau trees are part of their childhood. At the beginning of May, Sau flowers bloom with a slight sour fragrance, and it is also the time when little girls pick up flowers that fall on the sidewalks, thread them onto strings to make necklaces, and pretend to be brides.

When the fruits are still green or already ripe, many kids choose the uncrowded times at noon to shoulder ride on each other to pick the fruits, then gather at street corners to devour their booty.

Today, every time Sau leaves fall and color the sidewalks with yellow, girls and women around the capital put on makeup and beautiful clothes, then go to Phan Dinh Phung Street to take pictures and post them on social networks. Phan Dinh Phung, a street with the highest number of Indochina dragonplum trees, is considered the most beautiful street in the city. 

More than a century has passed, and the first Sau trees remain there, standing strong through inclement weather.

Sau - one of favorite fruits for Hanoians and people in Northern Vietnam. Photo: Bnews

Ingredient of Hanoi’s specialties

Today, with its special sour flavor, Sau is an important and irreplaceable ingredient of typical dishes of Hanoi such as simmered duck with Sau, sweet and sour soup with rib or pork, sour braised meat, fish or shrimp, or sour soup of morning glory - a very popular dish of every family to cool down the heat in summer.   

Of them, Sau juice, home-made syrup, is good to taste with ice, an ideal drink in summer. 

Meanwhile, baby Sau fruits soaked in fish sauce or boiled morning glory soup are no longer a specialty of Hanoi, but in many other places nationwide. Sau is so popular that people store it for year-round usage. Notably, Sau fruits in Vietnam have been shipped abroad with dozens of tons.   

Especially, dried Sau fruits become one of the typical foods of Hanoi, and a popular gift for visitors. 

Sweet and sour Sau juice is an ideal drink for summer. Photo: Hanoi culinary expert Nguyen Phuong Hai

Sau soft dried fruit - favorite for people in Vietnam and visitors.