Swallowwort is neither dandelion nor viola yedoensis, so it can't be confused. There are many kinds of bitter herbs, but not many have purple flowers.
There are all kinds of pictures about amaranth on the Internet, and the pictures on the encyclopedia are really true. Purple sowthistle is developed into purple sowthistle tea because of its high nutritional value, which is more convenient for people to use.
One problem is that many fakes also appear, especially in Shandong and other places, so we should pay attention to distinguish this. The real origin of purple bitter herbs is in Guannan, Jiangsu, but it is mountainous in Shandong. Generally, purple bitter herbs must be weathered.
Experience can only be used by people, but purple bitter herbs in the mountains can't be used, because they are often covered by other plants and can't completely resist the frost of nature, so they are useless. Never listen to Dashan.
Sonchus oleraceus has many functions, all of which are extended from the treatment of cholecystitis. It used to be used to satisfy hunger, especially in famine years, but it was used to cure diseases and save lives. Purple bitter vegetables are also exquisite when used, and even when used to satisfy hunger, they often remove the bitter core in the middle so as not to feel bitter. It is not recommended to eat bitter vegetables alone, but it is a bit tricky to add brown sugar when it is used to treat the stomach or maintain it. Brown sugar is added after cooking, not when cooking. Otherwise, the efficacy and function of purple bitter medicine will be difficult to play.