How to know if a mushroom is poisonous

According to the National Institute of Toxicology and Forensic Sciences, some 1,500 species of higher fungi are known on the Iberian Peninsula, of which some 100 contain more or less dangerous toxic substances. Learning how to distinguish poisonous mushrooms from edible ones is very important before you go out to pick them, as it can lead to food poisoning or even death.

How to know if a mushroom is poisonous? The first and most important advice is to be clear that you should never eat a mushroom if you are not absolutely sure that it is not poisonous. Therefore, it is best to attend an introductory course or a scheduled excursion for a first approach. In addition, in this Dolboard article, we give you some tricks for beginners on how to recognize a poisonous mushroom.

Tricks at first sight

If you are new to mycology and mushroom picking, your first goal should be to ‘train’ your eyes on the first mushroom identification. As a precaution, at first glance, you should discard any mushrooms with a deteriorated appearance, such as those that are broken, split, or have a ‘rotten’ appearance. This is because they could be in poor condition and, if their appearance is altered, their accurate identification will be more difficult.

After this step, you should keep in mind that there may be mushrooms that are very similar in appearance, but one is poisonous, and the other is edible. It occurs, for example, with Amanita caesarea and Amanita muscaria, the first being harmless and the second toxic. It also happens with the different species that make up the family of the appreciated boletus, which you have to know very well so as not to make mistakes.

Finally, do not trust the size. It has nothing to do with toxicity. There are small mushrooms that keep powerful poisons inside. If you are a beginner and want to learn more about the world of mushroom picking.

Bright colors and an unpleasant smell

Mushrooms can surprise us with a multitude of shapes, sizes, and colors. Some are familiar to us and make us think that we are dealing with one of the most common edible mushrooms, such as chanterelles, boletus, oyster mushrooms, or mushrooms. Although they are familiar to us, we must be completely sure before considering them suitable for our basket.

If you wonder how to know if a mushroom is toxic, look at these details:

  • Be wary of bright colors like reds, bright oranges, or greenish. There are many toxic mushrooms that show them, making them as striking as they are dangerous. If you see these tones, not only on the top but also on the stem, better leave it.
  • Another little trick that should put you on the alert is to check that when you cut the stem (at the harvesting point or at the time of cooking) it changes color and takes on a bluish hue or even releases some kind of milky liquid. In both cases, avoid the risk and do not eat it.
  • Finally, a mushroom that gives off an unpleasant odor or that reminds of some chemical sulfur compound is surely not edible.

White sheets, ring, and volva

To know what poisonous mushrooms are, you must know three easily recognizable and common elements in them: the white plates, the ring, and the volva. They appear, above all, in the amethyst family, some of which are very toxic. Pay attention to these three elements:

  • Below the upper area (cap) is the hymenium, where the mushroom stores its spores. It can have different shapes such as tiny tubes, pores, or sheets. When you pick a mushroom, turn it over and see if the hymenium is made up of white plates. If so, it is a potentially dangerous fungus.
  • Also, check if a ring-shaped ‘web’ appears on the stem. You may see one or even two. It is another warning of possible toxicity.
  • Finally, it is important to take the mushroom in its entirety and not cut it at ground level so that you can see the end of the stem. Many of the most harmful amatites for humans have a flare at the end, which is known as volva. This feature can also be indicative of danger.

If you appreciate these three elements, unless you know exactly what mushroom it is, it is preferable not to pick it.


When learning how to tell if a mushroom is edible or not, another clue that should alert you is the veil. Some inedible mushrooms have a kind of almost transparent web, which falls from the top to the stem or from the stem to the foot, forming a light veil. This is another possible indication that you are dealing with a poisonous mushroom. Therefore, as a precaution, do not pick veil mushrooms.

Dark or pink spores

When collecting mushrooms in the forest, it is advisable to carry a small piece of paper or cardboard, with which you can easily see the color of the spores released by the fungus when you pick it. When you have the mushroom in your hand, put the hat under the cardboard, move the mushroom a little and observe the color of the spores it releases. If the spores are very dark or have pink tones, they can be toxic or taste bad.

These tricks on how to know if a mushroom is poisonous will help you, If you prefer to play it safe, it is best to start by learning a few edible mushrooms.


  • It must be insisted that before eating a mushroom it must be identified without margin of error. Otherwise, it is always preferable to give it up given the danger, even death, that it may entail.
  • There are many supposed ‘infallible’ tricks circulating to differentiate edible mushrooms from poisonous ones, beware of them! For example, it is said that if you bring a silver object, such as a spoon, close to a mushroom, and that object remains unchanged, without turning black, the mushroom can be eaten. Tricks of this kind have no scientific basis and are dangerous to resort to. Only caution and accurate mycological knowledge guarantee safe mushroom picking.

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