The superior Nostoc flagelliforme is black and long, and the boiled soup is red. There are wig dishes for sale in the market, and most of them are copied with millet whiskers or goldfish aquatic plants dyed black. To distinguish between true and false, try soaking Nostoc flagelliforme in water. After soaking in water, Nostoc flagelliforme becomes thick and swollen, and it is not easy to break. Nostoc flagelliforme with a neat shape and a length of about 10 cm is preferred. Don't choose it too fine and don't smell greasy.

A few tips:

① Color: True Nostoc flagelliforme is grayish black; Wig vegetables are jet black, dark brown or green brown.

② Shape: Nostoc flagelliforme is a fine and uniform cylindrical filamentous body covered with transparent colloid; Wig vegetables generally have no transparent colloid, and some of them are filiform and colloid, but they are branched with thick bottom and thin top.

③ Texture: The fingers of Nostoc flagelliforme are soft and not fragile; And some wig dishes are fragile.

④ Soaking: Nostoc flagelliforme sinks rapidly in water and turns pale yellow after soaking; Wig vegetables sink slowly, and some soaking liquids are blue-black

⑤ Taste: Nostoc flagelliforme is fragrant and crisp; Wig vegetables have no smell of Nostoc flagelliforme.

Planting techniques of Nostoc flagelliforme are drought-resistant, but grow well in humid environment. Therefore, it is appropriate to choose sandy soil or alkaline soil with good permeability. The soil should be fertile, made into a flat bed and covered with a layer of fine sand. Planting: Cut the shredded algae into 3cm segments, and bury one end in the soil for about 0. 2cm. Close planting is 200 ~ 300/m2. You can also use nest planting, that is, take 0.1~ 0.3g of air-dried Nostoc flagelliforme as a nest and sow at a density of 25 ~ 30 nests/m2. Cover with a layer of fine sand after sowing. 3. Management and harvesting After sowing, spray water twice a day to keep the air moist. After growing for 50 days, the weight can be increased by 2. 5-4. 5 times. When the algae filaments grow into blocks, they can be harvested. Early spring and late autumn are harvest seasons, and harvest is carried out in the early morning. After harvesting, cleaning, grading and airing can be packaged and marketed.