The shiitake mushroom is also known as shiitake mushroom, shishin, shiitake mushroom (Japanese) or winter mushroom. Shiitake mushroom fruiting bodies are solitary, clustered or grouped. The cap is round, usually 5 to 10 centimeters in diameter, sometimes up to 20 centimeters, the surface of the tea brown, dark brown, covered with dark scales. When young, the edge is involute, with white or yellow cotton hairs, disappearing with growth. There is a fungal curtain under the cap, which later ruptures, forming an incomplete fungal ring. When mature, the edge of the cap is rolled back and cracked. The flesh of the mushroom is thick, white, tough, and the dried mushroom has a characteristic flavor. The gills are curved, white, and produce spots when injured, turning reddish-brown in the late stage of growth. The stipe is 3-6 cm × 1-1.5 cm, centrally or eccentrically borne, internally firm and fibrous. The part above the hyphae is white, the part below the hyphae is brownish. Spore prints white. Mycelium has lock-like unions. Due to differences in growth conditions (species of tree in which they occur, light, temperature, humidity, latitude, longitude and altitude of the mushroom farm, geographic isolation, etc.), shiitake mushrooms have all kinds of variations in morphology, quality, and color, but these differences and variations are not yet available taxonomically to be used as characteristics of a new subspecies or a new variant. At present, there are many varieties (strains) of shiitake mushrooms that meet people's economic purposes. For example, according to the production season, there are spring type, summer type, fall type, winter type, spring and fall type shiitake mushrooms; according to the size of the cap, there are large-leafed mushrooms, medium-leafed mushrooms and small-leafed mushrooms.