Over the past few tutorials we have been looking at a great many species within
the order Agaricales. For the final tutorial on this fascinating order,
we will discuss one of the most influential families in the entire fungal queendom,
the Amanitaceae. Mushrooms in this family can be edible, deadly poisonous,
or hallucinogenic. In this tutorial, we will specifically discuss the genus Amanita.
These sturdy mushrooms have pale gills free from the stipe, an annulus below the cap,
and a universal veil at the base of the stipe that forms a volva or bulb. When identifying Amanitas,
it is crucial to dig up the whole mushrooms so as not to miss the presence of the volva. All Amanita
mushrooms possess a pale white spore print. Many Amanitas are mycorrhizal with a variety
of tree species. The life of an Amanita begins with the formation of an egg-like structure.
These can be mistaken with puffball mushrooms, but when cross-sectioned, you will not see white
tissue. Instead, you’ll see what will become the cap and stipe of the mushroom. The cap and stipe
will push through the egg, sometimes leaving remnants that form warts on top of the cap. The
partial veil will break from the underside of the cap to form a ring or annulus around the stipe.
Within the genus Amanita, there are two subgenera. The subgenus Amanita and the subgenus Lepidella.
Within each of these subgenera, there are a number of sections. We will discuss three sections within
the subgenus Lepidella: sections Lepidella, Phalloideae, and Validae. First, we will begin by
discussing the Genus Amanita, subgenus Lepidella, section Lepidella. These are larger mushrooms,
generally white in color. They have a powdery or floccose texture on the stipe and cap.
The term floccose describes loose cotton-like scales on the mushroom. When handling powdery
lepidella mushrooms, the powder may stick to you as you touch them. Some smell intensely of
chlorine and possess an amino acid derived liver toxin called allenic norleucine. Although touching
a mushroom will never lead to poisonings, this poisonous mushroom is quite offputting to handle,
yet elegant in structure. The base of the stipe forms a thick bulb instead of a volva. Unlike all
other amanita sections, section lepidella is the only section that includes species
that can live without a mycorrhizal relationship with a plant species. Amanita cokeri,
is a species in the lepidella section and common in oak-pine forests in eastern North America.
The mushroom possesses a thick bulb at the base of the stipe which can penetrate into the ground. The
gills are a beige to creamy white color. Next, we will discuss the Genus Amanita,
subgenus Lepidella, section Validae. These mushrooms can be a variety of colors. The
base of the stipe always forms a bulb, and there are scales on the cap. These mushrooms
are mycorrhizal with hardwood and softwood trees. Amanita rubescens, commonly called the blusher, is
brown to reddish in color. It receives the species epithet and common name blusher from the reddening
of the flesh when bruised or cut. The mushroom is common around Great Britain and Ireland. In the
Americas, the mushrooms that are quite similar to Amanita rubescens are different species.
Let’s transition to mushrooms in the Genus Amanita, subgenus Lepidella, section Phalloideae.
These mushrooms have a bulbous base to the stipe, and a flap-like universal veil in the form of a
volva is always present. This taxon is infamous because it contains mushroom species that cause
the most deaths by mushroom poisoning in the world. Amatoxin is the collective name of the
group of toxic compounds in these mushrooms. They cannot be denatured with heat, so cooking
the mushrooms does not make them less lethal. Amatoxins are inhibitors of RNA polymerase II,
an enzyme that is essential for the production of proteins. When ingested, liver cells will
uptake the molecule. Amatoxin will bind to the liver cell’s RNA polymerase enzymes and cause
the cell to burst and die. The symptoms of this process display as liver failure, kidney failure,
and respiratory failure. Fifteen percent of those poisoned with amatoxin will die within ten days.
Although this is a frightening scenario, there is nothing to fear if you learn proper
identification of Amanita species. Amanita phalloides, commonly known as the death cap,
is the perpetrator of many of these poisonings. This is the type species of the section
Phalloideae. The mushroom is fairly large, with a cap ranging from 2 to 5 inches in diameter.
The cap is a pale olive color. The stipe has a floppy annulus near the cap
and a sac-like volva at the base. The scent has been described as honey-sweet to sickly-sweet.
Another mushroom type in section Phalloideae is commonly called the destroying angels.
This applies to three Amanita species that exist in distinct locations. Amanita bisporigera in
eastern north america, Amanita ocreata in western North America, and Amanita virosa
in Europe. These mushrooms have a white stalk, gills, annulus, and cap. The volva encapsulates
the entire mushroom in an egg when young. At this stage, it can resemble puffball mushrooms.
We have discussed the sections in the subgenus Lepidella: sections Lepidella, Validae,
and Phalloideae. Let us now cover three sections in the subgenus Amanita: sections Vaginatae,
Caesareae, and Amanita. Section Vaginatae consists of mushroom species without a bulb at the base of
the stipe, and that do not possess a ring. At the base of the stipe, there will be a sac-like volva.
Amanita vaginata, commonly known as the grisette, is the type species for the section. The species
epithet vaginata originates from the Latin term “vaginatus” which means sheathed, referring to the
volva at the base of the stipe. Amanita vaginata has gray caps without remnants or scales from the
universal veil. The caps have a raised central area called an umbo. The edge of the cap is
striated. The species is edible but not highly sought out due to its similarity to mushrooms
in the Lepidella subgenus. However, no mushrooms in the Amanita subgenus contain deadly poisons.
Section Caesareae contains beautifully-colored mushroom species. These mushrooms do not have a
bulb at the base of the stipe, possess a sac-like volva, and a ring. Along the stipe of many of
these species, there is a pigmented felt-like to fiber-like surface texture. Amanita caesarea,
commonly called Caesar’s mushroom, is a large, bright orange and edible fungus.
Amanita caesarea is exclusive to Europe. Amanita jacksonii is the caesar’s mushroom
native to North America. The name Caesar originates from the fact that Roman
emperors would eat the mushroom as a delicacy. Ancient accounts tell the story of Agrippina,
a prominent female figure during the early Roman Dynasty. Ancient sources say she replaced a plate
of Amanita caesarea with Amanita phalloides, the death cap mushroom, to feed her husband Claudius.
Although there is disagreement of how much Amanita phalloides played a part, Claudius did die,
and Agrippina successfully enabled her son Nero to take the throne as Roman emperor.
Our last section, and the last mushrooms we will discuss in the order Agaricales,
is genus Amanita, subgenus Amanita, section Amanita. This section includes arguably the most
recognizable mushroom in the world, Amanita muscaria, commonly known as the fly agaric.
Amanita muscaria classically has a bright red cap with white scales, stipe, ring, bulb, and volva.
You can find this species almost anywhere in the world. There are a number of variants as well. For
example, Amanita muscaria variation Guessowii is the orange to yellow variant found in the
southeastern United States. Amanita muscaria is the center of much lore and popular culture,
including the Super Mario Brothers red mushroom powerup, as well as Disney’s Alice
in Wonderland. Historically, Amanita muscaria was reported as a toxic and deadly mushroom.
However, it is now known that the mushroom is not deadly, though it does contain a number
of pharmacologically active compounds. Two of these compounds, muscimol and ibotenic acid,
are known to be psychoactive. Historically, native tribes of Siberia would prepare the mushroom to
use as a hallucinogenic drug. There is a tale of Siberian shamans who would find Amanita muscaria,
dry the mushrooms in spruce or fir trees, and then deliver the hallucinogenic mushroom gifts
via a reindeer sleigh. Due to the mushroom’s red and white coloring, this combination of details
comprises an uncanny resemblance to the story of Santa Claus.
To conclude, Amanita muscaria is a prime example of the beauty and cultural impact that mushrooms
possess. And with that, we have finished discussing much of the Order Agaricales,
discussing 15 families and over 30 species. This is just the beginning of the diversity
of mushrooms, so let’s move forward and continue learning about mushroom species.