Agaricus bisporus

Agaricus bisporus, commonly known as the cultivated mushroom, is a basidiomycete mushroom native to grasslands in Eurasia and North America. It is cultivated in more than 70 countries and is one of the most commonly and widely consumed mushrooms in the world. People grow it in many places because it is tasty and nutritious.

This mushroom has two color states when it is young – white and brown – and as it grows, it can be called by different names such as chestnut, portobello, portabellini, button, cremini, and champignon de Paris. Each of these names refers to a stage or type of the same mushroom.

Although Agaricus bisporus is safe to eat, there are some poisonous mushrooms in the wild that look similar, like Entoloma sinuatum. Because of this, it is important to be careful when picking mushrooms and make sure they are correctly identified before eating them. This mushroom often grows in rich soil and compost, which is why it is easy to cultivate.

Description

The cap of the wild Agaricus bisporus mushroom is pale grey-brown with flat scales on a lighter background, fading toward the edges. It starts round and flattens out as it grows, usually about 5 to 10 centimetres (2 to 4 inches) across. The narrow, crowded gills are free and change color from pink to red-brown, and finally to dark brown with a whitish edge. The stem is cylindrical, up to 6 centimetres tall and 1 to 2 centimetres wide, and has a thick, narrow ring on it. The flesh is firm and white but turns pale pinkish-red when bruised.

The spore print of this mushroom is dark brown. The spores are oval to round, measuring about 4.5–5.5 micrometres by 5–7.5 micrometres. Most spores are carried by two-spored structures, but some varieties have four-spored structures.

The common mushroom can sometimes be mistaken for young specimens of a group of poisonous mushrooms in the Amanita genus, called destroying angels. These can be told apart by their cup-like volva at the base and pure white gills, unlike the pinkish or brown gills of A. bisporus.

Another common mix-up is with A. xanthodermus, an inedible mushroom found worldwide in grassy areas. This mushroom smells like phenol and turns yellow when bruised, and it can cause nausea and vomiting in some people.

The poisonous European species Entoloma sinuatum looks somewhat similar but has yellowish gills that turn pink and lacks a ring.

Taxonomy

The common mushroom, known scientifically as Agaricus bisporus, has an interesting history. It was first described in 1871 by an English botanist and was later studied by a Danish scientist. Over time, its scientific name changed until it settled on the current name in 1946.

Names

This mushroom has many names depending on its color and age. When it is young and white, it can be called a common mushroom, white mushroom, button mushroom, cultivated mushroom, table mushroom, or "champignon de Paris" in French. When it is young and brown, it might be known as a Swiss brown mushroom, Roman brown mushroom, Italian brown mushroom, cremini mushroom, or chestnut mushroom. When it grows larger and matures, it is often sold as a portobello.

Distribution and habitat

This mushroom is found all over the world. It grows in the fall and winter, especially near cypress trees, rich soil, compost, and manure.

Cultivation

Mushrooms like Agaricus bisporus are grown in over 70 countries around the world. In 2022, the total amount of mushrooms produced was 48 million tonnes, with China making up most of this amount.

People have been growing these mushrooms for a long time. In 1707, a French scientist wrote about how to grow them. At first, it was hard because the mushrooms often got sick. But in 1893, scientists found a way to keep the mushrooms healthy. In 1925, a white mushroom was found growing among brown ones in Pennsylvania, and it became popular because it looked nicer. This is how many white mushrooms in stores today were developed.

Nutrition

Agaricus bisporus mushrooms are made up of 92% water, 3% carbohydrates, 3% protein, and almost no fat. When you eat 100 grams (about 3.5 ounces) of raw white mushrooms, you get 93 kilojoules (22 kilocalories) of energy. They are a great source of some B vitamins like riboflavin, niacin, and pantothenic acid, and they also have good amounts of minerals such as phosphorus and potassium.

Mushrooms have a little bit of vitamin D, but when they are exposed to UV light, the amount of vitamin D they contain goes up a lot.