Brasenia schreberi is the young stem and leaves of BraseniaschreberiGmel. in the water lily family, also known as watercress, horseshoe lettuce, lake lettuce, etc. It is a perennial rooted aquatic herbaceous plant. It is one of the most precious vegetables. It is rich in protein, carbohydrates, fat, a variety of vitamins and minerals. Mainly produced in Zhejiang, Jiangsu provinces in the Taihu Lake basin, late April to late October picking with a curly leaf of the young slightly. Brasenia schreberi has the efficacy of clearing away heat, inducing diuresis, subduing swelling and detoxifying. It is used to treat hot diarrhea, yellow gangrene, carbuncle and boils. It is also used to remove vexation, relieve heat and eliminate phlegm in the Compendium of Medical Sciences. Brasenia schreberi is cold in nature, it should not be eaten and eaten for a long time.