Death Cap Mushroom FAQ: 13 Things to Know

What You Need to Know About Death Cap Mushrooms

With a name like “Death Cap”, you may not be surprised to learn that the main thing you need to know about this member of the Amanitaceae family is that it is poisonous enough to kill a human if ingested. 

The toxins present in the Death Cap act mainly on the liver and treatment is difficult. There is no known antidote yet. 

Identifying the Death Cap

Mushroom Identification

Mushroom identification is a complicated field of study. You must pay attention to many small details when determining a mushroom species, and you must pay attention to ALL of the details together.

When identifying mushrooms you will be looking at the size and shape of the cap, the shape of the stem and how it attaches to the cap, the style of gills, and how they are attached to the cap. You’ll be looking for things like a “universal veil”, a partial veil, cups, rings, and warts.

Of course, the color, smell, texture, and taste of the mushroom are all clues to its identity. Another indispensable mushroom identification tool is a spore print. The color of the spores can be a solid clue to identifying the species. 

What Does a Death Cap Look Like And Where Is It Found?

The time of year to find fruiting Death Caps is late summer through late fall.

The death cap grows under hardwood trees, especially tree species originally from Europe, such as oak, chestnut, linden, and hornbeam, where the mushroom is native. They can also be found near pine, beech, birch, and spruce trees. 

Color and Texture

The death cap is mostly white, but usually with a distinctive greenish or yellow-green tint. They can also begin to be olive-brown as they mature. The color is described as almost metallic, “brassy yellowish-green” by mycologist Brenda Callan.

After a heavy rain, the caps can lose their green tinge and become entirely off-white. 

The death cap is usually slightly sticky to the touch. 

Size and Shape

Young death caps have a rounded cap that curves around to nearly touch the stalk. As they mature the caps flatten out, first into a typical dome shape, becoming nearly flat as the mushroom reaches maturity. The caps are typically 3 to 6 inches in diameter. 

Note: When death caps first emerge they are round or egg-shaped and sometimes mistaken for puffballs (which are edible). If you think you have a puffball, cut it in half to be sure. Puffballs are solid inside with no gills. If you see gills you probably have a death cap. 

Gills

Look at the underside of the mushroom’s cap to see the gills. The gills of a death cap are white, thin, and crowded near the outside of the cap. The gills are narrowly attached to the stem and do not run down the stem, they are only on the cap. 

Stem

The stem of the death cap is about 3 to 6 inches tall and less than an inch thick. It is usually off-white and sometimes has small scales. 

There is often a ring around the stem just below the cap. This is a remnant of the partial veil that protected the mushroom’s gills while it grew.

At the base of the stem, there will usually be a small sack or cup. This is the remnant of the “universal veil” or volva that all amanitas start their growth inside. Sometimes the volva is hidden under the dirt and it takes some gentle digging to see it. 

Never assume a mushroom is not an amanita if you don’t see the cup, it may have been broken off, or disintegrated. 

Smell

Death caps have a slight ammonia smell that is unusual in mushrooms.

Spore Print

Taking a spore print involves placing the mushroom cap gill-side-down on the piece of paper and leaving it for several hours or overnight. Make sure the mushroom cap is safe from being knocked around, and out of reach of kids and pets.

Because the spores of death caps are white, you’ll want to use a dark piece of paper to catch them. 

Can You Survive Eating a Death Cap?

It is possible to survive eating a death cap with proper medical assistance. 

Because the toxins in the death cap inhibit liver function, and because they circulate through your body over and over until they are eliminated by the kidneys, it is vital to remain sufficiently hydrated for your kidneys to keep up with this process. 

Two of the main symptoms of death cap poisoning are vomiting and diarrhea. This can make it nearly impossible to stay hydrated enough to survive and makes hospital admission one of the only ways to do so. 

What Makes a Death Cap Mushroom So Deadly?

The toxins in death cap mushrooms, amatoxins, do not produce symptoms for 6 to 24 hours after ingestion. By this time the poison is fully absorbed into the body and the only way out is through the kidneys. 

Amatoxins stop the synthesis of mRNA, causing cells to break down. The liver is affected first, followed by the kidneys, then all other organs. 

How Fast Does a Death Cap Kill You?

It takes 3 to 5 days for death cap poisoning to finish its work.

As mentioned, the symptoms of death cap poisoning don’t show up for anywhere from 6 to 24 hours after ingestion. 

Besides vomiting and diarrhea and the cramps that come with them, a person may experience dizziness, headache, and coughing, among other symptoms. They may even think they have the flu or some other illness. 

At some point, the person typically feels better. The abdominal symptoms clear up. But the poison is still at work and death from multiple organ failure typically occurs 3 to 5 days after ingestion. 

Other Things to Know

Amatoxins are not damaged by cooking. They will be just as potent in a stew or stir-fry as they are fresh.

Don’t count on a mushroom being safe because you saw something else eating it. Rabbits, for example, are apparently not harmed by amatoxins.