Water shield has aliases such as water sunflower, dew sunflower, horseshoe medicine, pheasant tail medicine and water lotus leaf. Its color is green, and it is rich in protein and vitamins. It is a precious water hyacinth, which looks small and round, almost as smooth as a 50 yuan coin. It is one of the famous native products in the western period. West Lake has a long history of cultivating water shield. There is a record of "the third bridge of West Lake near Lai Jiao" in the Ming Dynasty's West Lake Tour. At present, it has been planted in Santan, silver moon and Guanyu, Huagang.

Water shield is a perennial aquatic plant. The leaves are oval and dark green, and there are colloidal transparent substances on the tender stems and leaves. The edible part is the new leaves that have not yet been unfolded after sinking into the water. Rich in protein, vitamins and trace iron, with high nutritional value. The soup or soup made by water shield is particularly delicious and is listed as a famous dish in Hangzhou. It is said that Emperor Qianlong visited Hangzhou many times, and every time he made soup with the water shield of the West Lake. "The flowers are full of Su Causeway willow smoke, and the weather is fine when collecting medicine." Spring is the best season for picking Chinese cabbage. The harvest period of water shield is very long, and it can be picked every two or three days from mid-April to late September every year, with the highest yield in July.

West Lake cuisine is a famous dish, which is as famous as Songjiang perch since ancient times. There is a record of eating perch in the Book of Jin. It is said that in feudal times, water shield was once used as a tribute. Now, the delicious "West Lake Water Shepherd Soup" is listed as a famous dish in Hangzhou. It contains two vitamins and trace iron, and is nutritious. In medicine, it also has the effects of lowering qi, stopping vomiting, moistening intestines and treating heat gangrene.

In history, "Three pools reflecting the moon" is the most famous water shield. Fresh water shield can be mixed with sugar; The nutritious, delicious and delicious "West Lake Shepherd Soup" is one of the famous dishes in Hangzhou.

Now only Taihu Lake in Jiangsu, West Lake in Hangzhou and Xiaoshan can grow water shield, which can be said to be very precious. Among them, the water shield of West Lake is the best.