"Three Mushrooms" in Northeast China, Daxing 'anling and Changbai Mountains in Northeast China are one of the important producing areas of wild edible fungi in China. Yuanmo, hazelnut and Hericium erinaceus are also called the "three big mushrooms" in Northeast China. Of course, there are many kinds of edible fungi near the sea, and it is estimated that there are at least 150 kinds. Yuanmo is born on the rotten wood of broad-leaved trees such as elm and linden, but it grows more in late autumn when the weather turns cold, so it is also called frozen mushroom. Most of hazel mushrooms grow in hazel forests and oak forests of FAGACEAE. At the end of Yuan Dynasty, the output of Corylus heterophylla was large, and most of them were processed into dried products and sold in the market. Hericium erinaceus grows on trees, and its leaflike body has white soft spines. After drying, it looks like Hericium erinaceus, hence the name. In fact, it is more like a hedgehog, so it is also called hedgehog mushroom. Hericium erinaceus is more precious, although it is also produced in other forest areas in China, but it is not as good as that produced in Northeast China. In addition, Hericium erinaceus is also one of the famous "eight treasures" foods. Xing 'anling forest region in Heilongjiang Province is also one of the important producing areas of auricularia auricula. Although the growing season of Auricularia auricula here is short, it is famous for its large flowers, thick meat and good color. Pleurotus ostreatus, also known as yellow mushroom, frozen mushroom and late borer, belongs to Hydroptera, Agaricus, Tricholomataceae and Pleurotus. It is a famous wild edible fungus in Northeast China, distributed in Hebei, Heilongjiang, Jilin, Guangxi, northern Shaanxi, Sichuan and other places. As long as the conditions are suitable, it can be planted in most areas of China. 1. Morphological characteristics Fruit bodies are fleshy, imbricate, overlapping or clustered. The diameter of the cap is 3- 12 cm, flat, hemispherical to flat, semicircular or kidney-shaped. It has a back edge with a width of 3- 12 cm. Yellow-green or brown, short fluff, smooth edge and easy peeling. The edge of the lid is rolled inward, and then rolled backward. Mushroom meat is white and thick. The bacterial folds are slightly dense, white or yellowish. Stipules lateral, short or sessile, with villi or scales. The spores are white, smooth and sausage-shaped, 4.5-5.5 μ m×1-1.6 μ m. The cyst is prismatic with swelling in the middle, 29-45 μ m×10-15 μ m. Second, life habits are born in autumn on dead trees of oak, poplar, birch or other broad-leaved trees. Hazelnut mushroom, also known as Armillaria mellea, Tricholomataceae. The fruiting body is of medium size. The tooth cap is 4 ~ 14cm in diameter, light khaki, honey to yellowish brown, brown after aging, with flat or upright scales in the middle, partially smooth and obvious edges. Mushroom meat is white. The bacterial folds are white or slightly pink until they are elongated and slightly sparse, and dark brown spots appear after aging. The stalk is slender, cylindrical, slightly curved, 5 ~ 13cm long and 0.6 ~ 1.8cm thick. It is the same color as the cap, with longitudinal stripes and hairy small phosphate, fibrous, soft and hollow inside, and slightly enlarged at the base. The fungus ring is milky white, pedunculate and double-layered when it is young. Spores are printed in white. Spores are colorless or yellowish, smooth, ovoid or nearly ovoid, 7 ~ 1 1.3 μ m× 5 ~ 7.5 μ m. In summer and autumn, they cluster on rotting wood, stumps or roots in the ground and forest, which often causes root rot of trees. Hazelnut mushrooms are distributed in Jilin, Tonghua, Baishan, Yanbian and other forest areas. It is a kind of wild edible fungus which is widely eaten and often sold in the market. The fruiting body contains D- threitol, C4H 10O4 and vitamin A, and can be used for treating lumbago and leg pain, rickets and epilepsy. It can prevent vision loss, night blindness and xerosis cutis, and enhance resistance to infectious diseases of respiratory tract and digestive tract. Armillaria mellea tablets made by mycelium fermentation have good therapeutic effect on vertigo patients caused by hypertension, vertebrobasilar insufficiency, Meniere's disease, autonomic nervous dysfunction and other diseases. It can also improve limb numbness, insomnia, tinnitus, apoplexy sequelae, etc. Glucan and peptidoglycan isolated from Armillaria mellea have anti-cancer effect, and the inhibition rate of sarcoma 180 and Ehrlich ascites cancer in mice is 70% ~ 80%. Hericium erinaceus is also called Hericium erinaceus, Hericium erinaceus, Cladosporiaceae or Hericium erinaceus. The fruiting body is medium to large, with a diameter of 5 ~ 10 cm and a maximum of 30 cm. It is oblate, hemispherical or head-shaped. Many succulent soft spines grow on narrow or short stems, and the spines are slender and drooping, with a length of 1 ~ 3 cm, white when fresh, and light yellow to light brown in the later stage. The seed layer is surrounded by thorns. Spores are colorless and smooth, spherical or nearly spherical, with oil droplets, 5. 1 ~ 7.6× 5 ~ 7.6 microns. The biological efficiency of artificial cultivation can reach 70%, that is, 1 kg dry material produces 0.7 kg fresh Hericium erinaceus, and the cultivated variety is Hericium erinaceus in Changbai Mountain. Wild mostly occurs in autumn, mostly on the standing trees or rotten trees of broad-leaved trees such as oak trees, and distributed in Changbai Mountain areas such as Jilin, Yanbian and Tonghua. Hericium erinaceus is a famous dish in China, and it is an important wild or cultivated edible fungus, which can obtain mycelium by submerged fermentation. According to the determination, every100g of Hericium erinaceus fruiting body contains 26.3g of protein, 4.2g of fat, 44.9g of carbohydrate, 6.4g of crude fiber, 0.2g of water/kloc-0, 856mg of phosphorus, 0.8mg of iron/kloc-0, 2mg of calcium and 2 mg of thiamine (b/kloc). Polysaccharides and peptides contained in the fruiting body of Hericium erinaceus can enhance human immune function. Its fermentation broth has inhibitory effect on mouse sarcoma 180.