Manual for identifying “high-quality imitation” edible fungi | Do you know about these high-risk “health foods”?

From the New Year's Eve dinner to the reunion dinner on the 15th day of the first lunar month, the delicacies on the table are mouth-watering. Delicious mushrooms are also a frequent guest on the table of the people. Boletus, morels, coral mushrooms, red mushrooms, chanterelles and other mushrooms have their own flavors whether they are made into soup or stir-fried. However, some "high-imitation" edible mushrooms are extremely dangerous. Today, let us get to know the poisonous mushrooms that we often eat by mistake!

Figure 1 Farmers in the mountainous area of ​​southern Shaanxi drying the wild mushrooms they collected (photo taken by the author in Shuang'an Town, Ziyang County)

However, the term "mushroom", which originated from the food world, does not imply that all fungi are edible. Many of them are not only inedible, but also highly poisonous.

"Red umbrellas, white poles, lie down together after eating...", a short video about preventing and controlling wild mushroom poisoning made by a fire brigade in Yunnan Province has recently become a hot search. Although this joyful short video has successfully made many people aware of the dangers of wild mushroom poisoning, the general public still does not know how to distinguish which mushrooms are poisonous in the wild.

Today, let us learn about the poisonous mushrooms that we often eat by mistake.

The leader of poisons - Amanita

Amanita, beware! It's not goose liver! The difference of one word may mean the difference between heaven and earth. According to incomplete statistics, the mortality rate of mushroom poisoning in Asia has reached 28.4% in the past two decades, and the culprits are mostly highly poisonous species in the Amanita family.

Figure 2 The prototype of “red umbrella and white stem” is actually the fly amanita of the Amanita family.

The Amanita family includes three genera, with about 600 species of fungi in the world, most of which are poisonous. Common highly toxic Amanitas include: Amanita phalloides, Amanita pantherina, Amanita lutea, Amanita pseudo-ovocapped, etc. These fungi are rich in a class of small molecule proteins called amatoxins. The poisoning mainly manifests in acute liver (kidney) damage, usually with an incubation period of 6-12 hours. The initial symptoms are nausea, vomiting, abdominal pain, diarrhea and other symptoms of acute gastroenteritis. Later, symptoms of multiple organ damage such as liver, brain, heart, and kidney will appear. Liver and kidney damage are the most serious, with a mortality rate of more than 90%. In addition, some patients will also have mental symptoms, and the general course of the disease is 2-3 weeks.

Figure 3 Amanita phalloides (upper left), Amanita pantherina (upper right), Amanita lutea (lower left) and Amanita pseudo-ovocapped (lower right) growing in the Qinling Mountains (photographed by the author in Zhongyang, Foping, Zhouzhi and other places in Hanzhong)

Regarding Amanita, Yang Zhuliang, an authoritative expert from the Kunming Institute of Botany, Chinese Academy of Sciences, gave a method for identifying poisonous and non-toxic Amanita:

Figure 4 Differences in morphological characteristics between non-toxic Amanita and highly toxic Amanita (Image from the Journal of Plant Protection)

Although there are identification methods, it is still difficult for non-professionals to distinguish and compare these characteristics in the wild. So for safety reasons, it is better to stay away from these "red umbrellas and white umbrellas".

All five poisons - Ring mushroom

In addition to the colorful and distinctive Amanita, there is another type of poisonous mushrooms that often appear in our daily environment. Although they look ordinary and plain in color, they are also rich in a variety of amatoxins. The symptoms of poisoning are mainly acute liver damage, and the mortality rate is extremely high. At the same time, some ring-shaped mushrooms can also produce acute nephrotoxicity, neurotoxicity, and intestinal toxicity, which can be said to have all five poisons. Moreover, the most common fleshy brown-scaled ring-shaped mushrooms and poisonous ring-shaped mushrooms are quite similar to the shiitake mushrooms we eat daily. Every year, incidents of accidental poisoning and death occur in my country. In the summer of 2018, there was a tragic case in Xi'an where three people were poisoned and one person died after eating fleshy brown-scaled ring-shaped mushrooms as wild shiitake mushrooms.

Figure 5: Poisonous ring mushroom (left) and fleshy brown ring mushroom (right) growing on a campus lawn (photo taken by the author in Xi'an)

How poisonous is it? - Amanita muscaria

Agaricus is mainly distributed in the Northern Hemisphere, with about 300 species, most of which contain toxins of the amanita peptide type. It is widely distributed in the northwest and southwest regions of my country. Common highly toxic species include Agaricus fasciatus and Agaricus fasciatus. This type of poison is quite similar to some edible mushrooms we eat every day, so it is often tried as Agrocybe agrocybe, Flammulina velutipes, Honey mushroom, etc. As a result, it is conceivable that people who have tried it are often "in danger of death". Agaricus fasciatus has become the most toxic mushroom in the world with a mortality rate second only to Amanita. Similarly, the toxic characteristics of Agaricus fasciatus are similar to those of Amanita, mainly acute liver (kidney) failure, accompanied by symptoms such as neuropsychiatric poisoning and gastrointestinal inflammation.

Figure 6 The Agrocybe fasciatus (left, taken by the author) is very similar to the Agrocybe fasciatus (right), and often causes poisoning due to accidental ingestion

Thick-flavored wax mushrooms - Boletus edulis, Russula subsparsely gilled, Ochre-deer flower mushroom

The term "delicious food is often poisonous" comes from "Guoyu. Zhouyuxia", which means that delicious food is often poisonous. It is very appropriate to use it to describe the following mushrooms.

Boletus is usually a general term for fungi such as Boletaceae and Songta Boletaceae. When it comes to fresh, thick, plump and tender boletus, everyone has heard of its legend. In the eyes of Yunnan people who love to eat wild mushrooms, it is even more of a favorite. However, not all boletus are safe to eat. Take the "Jian Shou Qing" that Yunnan people love the most. This is actually a general term for a type of boletus, because the mushroom will quickly change from white and yellow to green after being torn. There are many poisonous species in this type of boletus. After eating, people will have all kinds of incredible hallucinations. Although rarely fatal, it is also quite thrilling. In addition, many species of the genus Suillus, such as the pink spore boletus, are often mistaken for edible boletus such as yellow boletus in the wild and are mistakenly eaten. The toxins contained in this type of mushroom can cause strong irritation of the gastrointestinal tract and gastrointestinal inflammation. In the 6-18 hours after eating, you will truly experience what "the world is not worth it".

Figure 7: Boletus edulis (left, poisonous), Boletus edulis (middle, edible) and Boletus edulis (right, edible when young) (Photo taken by the author in Qinling Mountains)

Russula usually refers to mushrooms of the Russula family. As a large group in the Apiaceae order of the Basidiomycetes, it is widely distributed around the world and mainly grows in mountainous areas with an altitude of 300-1000m. There are many delicious species among them, and they are also wild mushrooms that we often eat. However, although there are many edible species, some of them are also dangerous. Among them, the one that is most likely to cause poisoning is the Subsemi-sparse Russula of the Russula genus.

Figure 8: Russula subsparsely gilled (left, highly poisonous) and Russula purpurogenum (right, edible, photographed by the author in Qinling Mountains) are similar in appearance and are often eaten as edible Russula.

Unlike mushroom poisoning such as Amanita phalloides and Agaricus cyclosporus, the incubation period of Russula sparsely covered poisoning is short, usually occurring within 10 minutes to 2 hours, with early symptoms of gastrointestinal toxicity such as nausea, vomiting, abdominal pain, and diarrhea. However, in the later stages, it can develop into rhabdomyolysis, leading to general weakness, chest tightness, palpitations, dyspnea, accompanied by general pain, muscle spasm pain, and other symptoms. In severe cases, death may occur due to multiple organ failure. Earlier this month, a serious mushroom poisoning incident in Guangdong was suspected to be caused by the accidental ingestion of Russula sparsely covered mushrooms.

Morchella (Morchellaceae) is a well-known delicacy and is often eaten by people who play in the wild. Its close relative, Morchella ochre (Morchellaceae, also belonging to the Ascomycota), is mainly characterized by its brain-like or deeply wrinkled appearance, which can easily be confused with the edible Morchella. Eating Morchella ochre raw or undercooked can cause hemolytic poisoning. Generally, gastrointestinal symptoms such as nausea, vomiting, upper abdominal pain and diarrhea appear within 30 minutes to 3 hours after consumption. Soon after, the development of hemolysis will lead to decreased urine or even anuria, the appearance of hemoglobin in the urine and anemia. The aggravation of symptoms can further lead to complications including acute renal failure, shock, acute respiratory failure, disseminated intravascular coagulation, etc., which endanger the patient's life.

Figure 10 The poisonous ochre-deer flower mushroom (left) and the delicious thick-stalked morel mushroom (right, taken by the author in Qinling Mountains)

Although wild mushrooms are delicious, they are also dangerous. So far, we still do not have a simple way to accurately distinguish poisonous and non-toxic mushrooms. In the "List of Poisonous Mushrooms in China" compiled by Professor Tuligul of Jilin Agricultural University and others, there are 435 poisonous mushroom species found in my country. It is very difficult to accurately distinguish these poisonous mushrooms from many wild edible mushrooms. There are often misunderstandings in the experience and methods of identifying poisonous mushrooms among the people. Some methods are only applicable to individual species and have no universal adaptability. Therefore, I advise all readers to love life and be cautious when eating wild mushrooms.