AGARICUS: CHARACTERISTICS, TAXONOMY, HABITAT, SPECIES - BIOLOGY - 2025

Agaricus is the generic name of a group of Basidiomycota fungi belonging to the Agaricaceae family that are characterized by developing fruiting bodies in the form of fleshy and generally large mushrooms. They have a hat that changes from hemispherical to slightly flattened, with a ring on the stipe and separate blades from the stipe.

The genus was originally described by Carlos Linneo and currently groups about 300 species around the world. They are saprophytes, generally humicultural and with relatively high nitrogen requirements. Some species develop among grasses, while others do so in forests or other more specific habitats.

Agaricus deserticola. Taken and edited from: This image was created by user Phalluscybe (phonehenge) at Mushroom Observer, a source for mycological images.You can contact this user here.English - español - français - italiano - македонски - português - +/−.

Some of the species ascribed to this genus are edible, including the mushroom (Agaricus bisporus), the most widely cultivated species of mushroom worldwide, with a production that for 2009 exceeded 4 million tons. The genus is also home to some toxic species, including Agaricus bitorquis and Agaricus xanthodermus.

characteristics

The fruiting body of Agaricus species is generally fleshy and large in size. The hat changes shape over time, being initially hemispherical, and then becomes slightly flattened after a certain period of life of the organism has elapsed. They are normally whitish or brownish species.

The hymenium has numerous free blades, that is, not attached to the stipe. These blades are fleshy and light-colored in recent fruiting, which later acquire pink tones and finally, in senescent organisms, turn into colors derived from the blackish-brown tone.

The ring is always present, it is light in color, it usually acquires different levels of development, it always separates easily from the hat and it can be persistent or fall off in older specimens.

The stipe is usually uniformly cylindrical, although it can also widen or narrow at the base. No return.

The meat is firm, compact, generally whitish in color and can change color when touched and / or cut, acquiring a reddish or yellowish color of different intensity levels depending on the species. The smell ranges from very pleasant to quite unpleasant.

Taxonomy

The genus Agaricus is located taxonomically within the family Agaricaceae, class Agaricomycetes, division Basidiomycota. The taxonomy of this genus is complicated because, although it was coined by Carlos Linnaeus in 1735, it was used to cover a great diversity of terrestrial fungi provided with plates and feet.

This name was later used with the interpretation that Fries made of it in 1821. Later Karsten makes an amendment to the genus, but excludes Agaricus campestris. Additionally, some mycologists have created new genera such as Psalliota, but including in it the type species of the genus Agaricus.

Due to all this, the authorship of the genre, as well as the valid definition of it, are still the subject of controversy. However, most taxonomists agree that this genus currently contains about 300 validly described species worldwide, some of which may additionally present varieties.

Habitat and distribution

Fungi of the genus Agaricus can grow in different habitats depending on the species. Many of them prefer open meadows and fields with abundant grasses, others prefer more wooded areas. Some grow under cypress trees and other tree species in the Cupressaceae family.

The organisms of the Agaricus minieri species are very specific in terms of their habitat, thriving only in dunes. Some species grow best directly on plant debris and others are common on the roadsides.

The genus Agaricus is cosmopolitan and has representatives on all continents, although it is more frequent in the northern hemisphere. The common mushroom has a wide distribution worldwide and has been introduced for cultivation purposes in many countries where it did not originally exist.

Representative species

Agaricus bisporus

The common mushroom is the best-known representative of the genus and the species of mushroom that has the highest production worldwide, because it is highly appreciated in the kitchen and has very important nutritional and medicinal properties. Its cultivation is carried out both traditionally and commercially.

There are several varieties of the species, of which the most common are A. bisporus var hortensis, which is the one that is generally marketed as common mushroom, and Agaricus bisporus var brunnescens, which receives the commercial name of portobello or crimini, depending on its size and its level of development.

This fungus can reach up to 18 cm in diameter of the hat, but generally does not exceed 13 cm. Its surface is covered by a powdery cuticle in which scales and spots can appear with age.

Agaricus campestris

Fungus whose fruiting body has a cap up to 12 cm in diameter and a foot 7 cm high, with a simple ring. It is an edible species with a very good taste as well as being rich in vitamins and minerals, but it provides very few calories, which is why it is very suitable to help you lose weight.

This species, despite having better organoleptic qualities than the common mushroom, is not cultivated commercially due to its long and complex life cycle and the fruiting body has a very short duration.

Additionally, this species has a drawback, since it can be easily confused with some toxic species, and even deadly, for which its consumption is not recommended if you are not sure of its identity.

Agaricus silvicola

Also edible species that is distributed in northern Europe and North America. Its fruiting body appears in autumn and features a hat up to 10 cm in diameter and a 4 cm tall stem.

Silvicula agaricus. Taken and edited from: Jerzy Opioła.

Agaricus xanthodermus

It is characterized because its fruiting body has a convex cap that in some mature specimens takes on the appearance of a cube with a flattened, dry and scaly surface that can reach up to 15 cm in diameter. Another important characteristic is that the foot has a yellow coloration.

This species has a wide distribution in the northern hemisphere, it grows associated with grasses, decomposing leaves and coniferous trunks. It gives off an unpleasant odor and its flesh turns yellow when cut.

Agaricus xanthodermus is toxic, although it does not cause death. Among the effects of its intake are gastrointestinal disorders such as abdominal cramps, nausea and diarrhea. Other symptoms of poisoning that appear less frequently are drowsiness, headaches and dizziness.

References

1. Agaricus. On Wikipedia. Recovered from: en.wikipedia.org.
2. Agaricus xanthodermus. On Wikipedia. Recovered from: en.wikipedia.org.
3. P. Callac (2007). II. The genus Agaricus. In JE Sánchez, DJ Royse & HL Lara (Eds). Cultivation, Marketing and Food Safety of Agaricus bisporus. Ecosur.
4. C. Lyre. Common mushroom (Agaricus bisporus): characteristics, taxonomy, nutritional properties, reproduction, nutrition. Recovered from: lifeder.com.
5. C. Lyre. Agaricus campestris: characteristics, taxonomy, habitat and distribution, reproduction, nutrition, properties. Recovered from: lifeder.com.
6. E. Albertó (1996). The genus Agaricus in the province of Buenos Aires (Argentina). Agaricus and Sanguinolenti sections. Bulletin of the Mycological Society of Madrid.