The Complete Guide to Agaricus Bisporus (Button Mushrooms)

It’s almost impossible to find someone who hasn’t at least heard of the famous button mushrooms. Scientifically known as Agaricus bisporus, this species is the best-selling fungus in most countries and has become a staple in modern kitchens all around the world.

But how much do you really know about button mushrooms? Here, we’ll give you all the important information you need on Agaricus bisporus, including its natural habitat, varieties, and taxonomical history. Plus, we’ll provide some tips for harvesting button mushrooms in the wild.

What is Agaricus bisporus?

Agaricus bisporus, also known as button mushroom, white mushroom, or champignon, is an edible fungi species found all over the world. It is, by far, the planet’s most popular edible mushroom—many people even nickname it “common mushroom” due to its prevalence.

The button mushroom represents a significant part of the bulk of the commercial mushroom business, generating over a billion dollars in revenue each year. Similarly, experts estimate that the average American consumes about one kilogram (two pounds) of Agaricus bisporus a year (1).

Agaricus bisporus is also a common target of both amateur and professional mushroom foragers. It grows in rich soils, usually near horse manure or compost piles. As such, it’s common to find it in grasslands where cows and other cattle feed. Although it’s particularly widespread in the northern hemisphere, it’s also possible to find it in southern tropical climates (2).

Like most mushrooms, Agaricus bisporus has a pleasant but subtle umami taste that blends earthy and meat-like flavors. Its odor is slightly sweet with natural notes. This makes it perfect for mixing with any ingredient—and may even be the ideal replacement for meat.

How do button mushrooms look?

Button mushrooms are thick mushrooms, with a cap that can measure up to 14 cm (5.5 in) and a stipe between 2–7 cm (0.7–2.7 in) long. Its color varies depending on the mushroom’s variety—some are pinkish white, while others turn brown or sepia with age.

A key characteristic of the button mushroom is that its stem will show red or brown spots when bruised. Its gills are thin but close to each other, often turning black as the mushroom grows old. Although hard to obtain from commercial specimens, Agaricus bisporus’ basidia produce a dark brown spore print (1) (2).

What are the varieties of Agaricus bisporus?

It’s hard to determine the exact varieties of Agaricus bisporus. Its enormous popularity has led to many different strains that mycology circles haven’t recognized. However, experts point out that there are at least six common varieties of the button mushroom:

• Agaricus bisporus var. albidus
• Agaricus bisporus var. avellaneous
• Agaricus bisporus var. bisporus
• Agaricus bisporus var. burnettii
• Agaricus bisporus var. eurotetrasporus
• Agaricus bisporus var. pettubescens

Still, it’s hard to pinpoint exactly what separates these varieties from each other. From what we’ve gathered, they differ in color and size but not in nutritional value. For example, var. bisporus is recognized as the brown variety and var. albidus as the white one (2).

This relates to the widespread confusion regarding the common names of Agaricus bisporus. Many people believe that portobello mushrooms (also known as portabella or portobella) and champignons are different Agaricus species—but both are A. bisporus. 

In general terms, you’ll probably come across two varieties when shopping for button mushrooms. The first is the classic small white mushroom, often used on top of pizzas or salads. The other is larger, with darker tones, which is usually served on its own.

History of button mushrooms

Agaricus bisporus goes way back in history, indicating its popularity isn’t new. For example, some researchers suggest that it may have played a role in the diet of Ancient Egyptians. Fungi were considered an absolute delicacy in Ancient Egypt, reserved only for the highest nobility. Button mushrooms are common in North Africa—so it’s not too far-fetched to think that some pharaohs were able to enjoy these amazing fungi on special occasions (3).

When it comes to modern mycology, the first reports of A. bisporus date back to the 1890s. At the time, mushroom foragers were amazed by a new species that grew in North America. In 1900, Charles Horton Peck described it under the name Agaricus brunnescens.

After that, A. bisporus disappears from scientific literature until 1971, when David Malloch started to unveil the species’ key characteristics. In a 1976 study, he established that the species is a synonym for Agaricus bisporus and Agaricus campestris (4).

Since then, not much has changed. Of course, some new varieties have been acknowledged—but it’s safe to say that A. bisporus is one of the most widely studied basidiomycetes out there.

Health benefits of Agaricus bisporus

Despite Agaricus bisporus being one of the most extensively studied mushrooms, there’s very limited information about its possible health benefits. In fact, experts point out that there aren’t any therapeutic products in the market containing A. bisporus. Yet, some recent research indicates that some of its components could impact specific bodily functions.

Two proteins in A. bisporus (ABL and Abmb) have been shown to stimulate and modulate the immune system. Similarly, they have potential as anticancer agents, as they slow down cancer cell growth. This makes them an interesting option for future anticancer treatments (5).

Another compound present in A. bisporus, frucogalactan, has also been studied for its possible health benefits. Researchers found this polysaccharide could have significant anti-sepsis, antinociceptive, and anti-inflammatory properties. As such, it could be of interest for future treatments of tissue damage (6).

More experimental trials involving mice and rats also show interesting properties of A. bisporus. In particular, it has been shown to decrease blood glucose and cholesterol levels. Similarly, it could help combat the age-related decline in brain function due to its possible antioxidant properties (7) (8).

Where do button mushrooms grow?

There isn’t much information available detailing where Agaricus bisporus prefers to grow. We assume that this stems from the popularity of this species—very few mycologists actually research it, as most people believe there’s nothing new to discover.

Button mushrooms are widespread in the northern hemisphere, with a strong preference for temperate climates. The species fruits for almost half a year, spanning late spring, summer, and autumn. It’s also possible to find it in the southern hemisphere, although it seems to be less prevalent there (2).

A. Bisporus usually grows on substrates such as manured soil, compost piles, and other enriched spawns. This may include lawns and stables. However, much of its popularity stems from the fact that it’s a simple mushroom to cultivate in artificial conditions (1).

What is ethical wildcrafting?

Ethical wildcrafting refers to the practice of picking mushrooms for medicinal purposes in a way that’s not damaging to the environment. It’s important to distinguish it from foraging, which refers to harvesting resources for food.

Wildcrafting ethically requires you to follow certain guidelines to avoid damaging the local fungi populations. Here are some of the basic rules of ethical harvesting:

• Do your research beforehand, including familiarizing yourself with the local flora and fauna and identifying endangered species.
• Carry a field guide to differentiate between various species.
• Respect the environment by carefully harvesting fruiting bodies and taking only what is necessary.
• Do not disclose patch locations to others.
• Follow legal guidelines, including requesting permission from landowners if harvesting on private property and checking local regulations if harvesting on public land.

If you’re new to wildcrafting or foraging, we recommend you look up local harvesting groups in your areas. These organizations will allow you to learn all these rules firsthand from professional and veteran mushroom farmers and harvesters.

Is it safe to wildcraft for Agaricus bisporus?

It’s never 100% safe to eat field mushrooms, be them A. bisporus or any other species. Particularly, white button mushrooms have several poisonous lookalikes. The most famous ones are the white variations of Amanita species—most of which can be fatal.

However, the danger doesn’t only come from possible lookalikes. Wild mushrooms often carry pathogens from the environment, which could lead to indigestion and other gastrointestinal symptoms. As such, it’s best to avoid consuming wild-picked fungi unless you’re under the supervision of a professional.

How do you take button mushrooms?

There isn’t a specific way to take Agaricus bisporus. These fungi are known for their versatility—they go well with almost any ingredient you can imagine. From salads to pizzas and everything in between, these gilled mushrooms are truly the jack-of-all-trades of modern kitchens.

As for cooking them, you can sautée, roast, boil, or simmer them; some people even eat them raw. But remember to never eat uncooked wild mushrooms. Instead, always use store-bought fungi that come from grocery stores or professional mushroom growers.

A key tip is to mix them with other mushrooms. Other Agaricales species, crimini, and any other edible fresh mushroom will go well with A. bisporus. For example, you could try adding pink oyster mushrooms and white buttons to a salad to replace meat.

Agaricus bisporus: Always in style

Agaricus bisporus is the most famous species among edible fungi—and for a good reason. Its versatile taste, lax growth requirements, and prevalence worldwide make it an easy choice for mushroom enthusiasts all around the globe.

If you want to find out about other types of mushrooms, keep up on shroomer. Here, you’ll find all the details you need about psychedelic and functional fungi from around the world, along with the latest news on medicinal research on edible mushrooms.

References

1. Kuo, M. “Agaricus Bisporus.” (2018). https://www.mushroomexpert.com/agaricus_bisporus.html
2. Paul Stamets, J.S. Chilton. “Agaricus brunnescens Peck.” in The Mushroom Cultivator (1983), 164–167.
3. Adel F. Ahmed, Ghada Abd-Elmonsef Mahmoud, Mohamed Hefzy, Zhenhua Liu, and Changyang Ma. “Overview on the edible mushrooms in Egypt.” Journal of Future Foods 3 (2023): 8–15. https://www.sciencedirect.com/science/article/pii/S2772566922000684?via%3Dihub
4. David Malloch. “Agaricus brunnescens: The Cultivated Mushroom.” Mycologia, 68(4) (1976): 910–919. https://www.jstor.org/stable/3758807
5. Wangsa Tirta Ismaya, Raymond Rubianto Tjandrawinata, and Heni Rachmawati. “Lectins from the Edible Mushroom Agaricus bisporus and Their Therapeutic Potentials.” Molecules, 25(10): 2368. https://www.mdpi.com/1420-3049/25/10/2368
6. Andrea C. Ruthes, Yanna D. Rattmann, Simone M. Malquevicz-Paiva, Elaine R. Carbonero, Marina M. Córdova, Cristiane H. Baggio, Adair R.S. Santos, Philip A.J. Gorin, Marcello Iacomini. “Agaricus bisporus fucogalactan: Structural characterization and pharmacological approaches.” Carbohydrate Polymers, 92(1) (2013): 184–191. https://www.sciencedirect.com/science/article/pii/S0144861712008454?via%3Dihub
7. Sang Chul Jeong, Yong Tae Jeong, Byung Keun Yang, Rezuanul Islam, Sundar Rao Koyyalamudi, Gerald Pang, Kai Yip Cho, Chi Hyun Song. “White button mushroom (Agaricus bisporus) lowers blood glucose and cholesterol levels in diabetic and hypercholesterolemic rats.” Nutrition Research, 30(1) (2010): 49–56. https://www.sciencedirect.com/science/article/abs/pii/S027153170900253X?via%3Dihub
8. Nopporn Thangthaeng, Marshall G Miller, Stacey M Gomes, Barbara Shukitt-Hale. “Daily supplementation with mushroom (Agaricus bisporus) improves balance and working memory in aged rats.” Nutrition Research, 35(12) (2015): 1079–1084. https://www.sciencedirect.com/science/article/abs/pii/S0271531715002250?via%3Dihub