Grifola frondosa is millet, which has strong vitality and can grow everywhere. It is found in fields, roadsides, cracks in walls, roofs and even "garbage dumps". But its humble growth does not mean that eating it will make you sick. The key is the process of making. As long as you pay attention to hygiene during processing, there will be no problem. All picked grey vegetables should be washed, soaked in cold water several times, each time for a long time, and then scalded with boiling water before being used for cooking or cold salad. The purpose of this is to remove porphyrin substances contained in it. If you eat untreated gray vegetables, it will cause solar dermatitis, edema will appear in all parts of the body exposed to the sun, and it will also cause symptoms such as hard eyes and ecchymosis under the skin, severe burning pain, tingling and itching, and severe blisters, blood bubbles and secondary ulcers. The disease usually heals itself. Grifola frondosa is also a kind of Chinese herbal medicine, which has the functions of clearing away heat and promoting diuresis, relieving itching and penetrating rash. Some people even smashed it into a greasy vitiligo. (Dr. Ke)