Mushrooms are a fascinating type of fungus that have been valued by humans for thousands of years as both food and medicine. There are thousands of mushroom species found worldwide, but only a fraction of these are known to be edible. Determining exactly how many types of mushrooms are edible is difficult, but estimates range from 2,000 to 3,000 species.
The diversity of mushroom species
Mushrooms belong to the fungi kingdom, which contains an incredibly diverse array of organisms. Fungi play essential roles in nutrient cycling, decomposition, plant growth, and other ecosystem functions. There are an estimated 3.8 to 5.1 million fungal species on Earth, though only around 120,000 have been identified so far.
Within the fungi kingdom, mushrooms are classified in the divisions Basidiomycota and Ascomycota. They are defined as the fleshy, spore-bearing fruiting bodies that certain fungi produce. Mushrooms emerge from an extensive underground network of mycelium that forms the main body of the fungus.
The number of identified mushroom species is estimated to be around 14,000 to 22,000 worldwide. New species are constantly being discovered by researchers and amateur mycologists (mushroom enthusiasts). For example, in 2021 alone, over 1,000 new fungi species were officially named and described.
Mushrooms exhibit an incredible diversity of shapes, sizes, colors, textures, and habitats. They can be tiny, single-celled yeasts or large organisms with caps up to 3 feet wide! Mushrooms grow in forests, grasslands, deserts, and every other terrestrial environment. Certain species even live entirely underground. This variety reflects the diverse lifestyles and functional roles that fungi inhabit.
Estimating the number of edible mushrooms
Out of the thousands of mushroom species identified so far, how many are known to be edible by humans? Providing an exact number is challenging for several reasons:
- Many species have not been tested for edibility due to limited research on mushrooms.
- Edibility can depend on how the mushroom is prepared – some require thorough cooking to remove toxins.
- Individual reactions to mushrooms vary based on tolerance.
- Mushroom edibility classifications are subjective and lack consensus.
However, mycologists estimate that between 2,000 to 3,000 species of mushroom are edible. This represents around 10-15% of known mushroom species. The number may be higher when including mushrooms that require special preparation to neutralize toxins and be rendered edible.
Below are examples of sources that provide estimates for the number of edible mushroom species worldwide:
- According to MushroomAppreciation.com, there are at least 2,000 edible mushroom species.
- The University of California estimates 2,000 to 3,000 edible species out of 14,000 documented mushroom species.
- Britannica lists approximately 2,000 species of mushroom that are edible without causing harm.
However, these sources also note that the exact numbers are difficult to pin down due to the challenges mentioned earlier. There is no definitive catalog of every edible mushroom species.
Major types of edible mushrooms
While the total number is uncertain, there are certain groups of mushrooms that make up the bulk of edible varieties consumed globally:
- Agarics – This order contains mushrooms that have gills that produce spores, including many well-known edible types like button mushrooms, portobellos, creminis, and shiitakes.
- Boletes – Mushrooms in this order have spongy, porous caps and stems instead of gills. Popular edible boletes include king boletes and ceps.
- Chanterelles – These trumpet-shaped fungi are prized for their fruity flavor and meaty texture. Common edible species include golden chanterelles and black chanterelles.
- Morels – Morels have a distinct honeycomb-shaped cap and hollow stem. They are renowned for their earthy, nutty flavor.
- Puffballs – Edible varieties of spherical puffball mushrooms have a soft white flesh when young. As they mature, the flesh hardens and turns yellow, brown, or purple.
- Truffles – These rare, underground mushrooms are highly aromatic. Popular edible truffle varieties include black truffles and white truffles.
Beyond these broad categories, many other wild mushroom groups contain lesser-known edible species, along with toxic lookalikes that must be avoided.
Geographic influences on edible mushrooms
The diversity and availability of edible mushrooms depends heavily on geography and climate. Some major patterns include:
- Temperate forests – Morels, chanterelles, boletes, and agarics thrive in temperate forests common in North America and Eurasia.
- Mediterranean regions – Truffles grow beneath oak and hazelnut trees in France, Italy, and other Mediterranean areas.
- Tropical forests – Tropical regions harbor a diversity of edible mushrooms, including varieties consumed in Southeast Asia.
- Grasslands – Meadow mushrooms and puffballs fruit abundantly in grassland environments worldwide.
- Mycorrhizal fungi – Truffles, chanterelles, boletes, and other prized edible mushrooms form symbiotic relationships with plant roots.
In addition, usage of wild mushrooms depends on cultural cuisine traditions. For example:
- Matsutake mushrooms are foraged intensively in Japan, Korea, and China.
- Slippery jack mushrooms are popular in Slavic cuisine but ignored in North America.
- Lepiota mushrooms are eaten frequently in Australia but avoided in other regions.
Therefore, what is considered an edible mushroom is strongly influenced by geographic availability, habitat, and human culinary culture.
Toxic mushrooms
While thousands of mushroom species are edible, there are also many toxic varieties. Deadly poisonous mushrooms belong to genera such as:
- Amanitas – This diverse genus includes the death cap mushroom, destroying angel, and other deadly species.
- Galerinas – Small brown mushrooms that contain the same toxins as the death cap.
- Conocybes – Tiny lawn mushrooms that cause abdominal issues.
- Lepiotas – Parasol mushrooms with variable toxicity depending on color.
It’s critical to never consume a mushroom in the wild unless you are 100% certain it is safe. Some mushrooms cause severe reactions or death if eaten raw or undercooked. When in doubt, discarding any questionable mushrooms is wise.
Common toxic mushroom effects include:
- Gastrointestinal issues – Cramps, vomiting, diarrhea
- Neurotoxicity – Tremors, seizures, confusion
- Organ damage – Liver, kidney failure
- Hemolytic anemia – Red blood cell damage
- Delayed reactions – Toxins cause harm days after ingestion
If you believe you’ve eaten a poisonous mushroom, seek emergency medical care immediately. Bring samples of the mushroom for identification.
Identifying edible mushrooms
When hunting for edible mushrooms, proper identification is crucial for safety. Here are some tips:
- Use a reputable field guide with detailed mushroom descriptions and photos.
- Learn the specific sensory characteristics of edible species – smell, color, texture, etc.
- Take spore prints of mushrooms to compare against known edibles.
- Study mushrooms in the wild alongside an expert mycologist.
- Start by collecting common, easy-to-identify edible varieties.
- When in doubt, don’t eat it!
Consuming even a small bite of some toxic mushrooms can be lethal. For beginners, it’s recommended to only pick mushrooms that can be identified with 100% certainty.
Some mushrooms have toxic lookalikes – even experts can make deadly identification errors on occasion. When starting out, only harvest easy, distinct edibles like giant puffballs, chicken of the woods, and bear’s head tooth fungi.
Cultivated edible mushrooms
For a safer option compared to foraging, many types of edible mushrooms can be cultivated at home or commercially grown:
| Mushroom | Key Characteristics |
|---|---|
| Button mushrooms | Widely grown white mushrooms with small caps. Includes cremini and portobello varieties. |
| Oyster mushrooms | Clustered white or grey mushrooms with delicate flavor. Grow on logs or substrate. |
| Shiitake mushrooms | Umami-rich Japanese mushrooms that grow on logs outdoors or indoors. |
| Lion’s mane | Shaggy white mushrooms with long, cascading tendrils. |
| Enoki mushrooms | Clusters of tiny white mushrooms with very long stems. |
| Maitake mushrooms | Overlapping fan-shaped caps that grow at the base of trees. |
Cultivated mushrooms provide a tasty, convenient source of mushrooms that does not require identification skills. However, foraging can offer access to wild mushroom varieties with unique flavors and textures.
Preserving edible mushrooms
Only a small number of wild, edible mushrooms can be found year-round. To enjoy mushroom varieties during off seasons, you can preserve them using these methods:
- Drying – Dehydrating mushrooms in a food dehydrator or low oven retains flavor well.
- Freezing – Blanch mushrooms briefly before freezing to stop enzyme activity.
- Canning – Mushrooms must be pressure canned for safety.
- Pickling – Most mushrooms can be pickled using vinegar, salt and spices.
- Oil/butter – Sauteeing then covering mushrooms in olive oil or butter preserves them.
When rehydrating dried mushrooms, add them to soups, stews or hot water and allow them to sit until softened. Frozen mushrooms can be thawed in the refrigerator before using.
Properly preserved mushrooms can last from several months to over a year. This allows enjoying wild, seasonal mushrooms long after they have stopped fruiting.
Conclusion
Estimates for the total number of edible mushroom species worldwide range from 2,000 to 3,000, representing around 10-15% of identified mushroom species. While an exact count remains elusive, thousands of wild mushrooms are known to be non-toxic for humans when properly identified and prepared. Geography, habitat, and culture influence which wild mushrooms are widely consumed. For safety, cultivating mushrooms at home or purchasing commercially grown varieties is recommended for beginners over foraging. With proper identification and preservation techniques, wild edible mushrooms can provide a bounty of unique and delicious fungi.
