Seaweed is an aquatic plant that grows in water all the year round. Its roots extend into stems and stems extend into vines. Vines are biochemically transformed into single goose-web-shaped broad leaves, with yellow pistils and white petals blooming in all seasons, and claw-shaped fleshy fruits and vegetables in summer. Its leaves are green, its stems are as white as jade, and its flowers are fragrant and pleasant. It is a natural wild watercress rich in vitamins and trace elements in protein. The edible methods are frying, boiling, stewing and boiling.

In the folk, the common recipe is "Dragon and Phoenix Lucky" soup. That is to say, in the soup of pig backbone, first put the broad bean rice into it and cook it, and then put the uncut seaweed stem into it. Its taste is fresh, refreshing and sweet, and it can improve eyesight, nourish liver, relieve cough and resolve phlegm after eating. It is a soup that middle-aged and elderly people often eat. In addition, the dish "dragon robe plus body" is also very good. The method is to fry fresh seaweed with diced ham until half cooked, add starch and seasoning, stew in sour vinegar for a while, and then take it out of the pot. It tastes sweet and sour, and has adjuvant therapeutic effect on cardiovascular diseases and frequent urination. There are also algae with high nutritional value, such as "Dragon Claw Arch Eye" and "Dragon Teng Blue Ocean".

Seaweed, a "rich" vegetable, has harsh growth conditions and can only grow in pure spring water. A little pollution of water quality or the application of chemical fertilizer in farmland will affect its growth. Therefore, people often judge whether the water quality is polluted by growing algae. The environmental protection department calls it "environmental protection dish". Where algae grow in spring water, the water quality must be of high standard. Heqingyou 18 Longtan, like Xinhua Village, is rich in seaweed, and locals treat seaweed as a kind of food to entertain guests.