To be clear, Amanita Bisporigera[i] is not the only destroying angel mushroom[ii]. The common name refers to an entire group of very similar-looking white or whitish Amanitas that all contain lethal doses of the same toxin. Figuring out which one you’ve got may be a fun intellectual exercise, but the distinction makes no practical difference. What matters is that you’ve got a destroying angel and should very definitely not eat it.
And yet some people do. Almost always it is a case of mistaken identity, as destroying angels have a number of edible look-alikes. Because the consequences of making such a mistake are so dire, many writers recommend simply not eating any of the look-alikes, either. While that might sound extreme to experienced foragers, it’s good advice for beginners who are not yet sensitized to the fine details on which identification depends.
But there’s no harm in looking at a destroying angel, and they are worth looking at. They are large, handsome mushrooms, with their own stately grace.
Identification and Description
Cap: Small to medium-large, initially egg-shaped, then opening to become bell-shaped to almost flat. Usually smooth on top, only rarely with patches of veil remnants. White to whitish. The interior flesh is also white and does not bruise.
Gills: White, free or almost-free from the stem.
Stem: Medium to long, slightly tapered, with a skirt-like ring of tissue partway up. There is also a cup of tissue around the base, but this can be underground or broken off, so it’s not always evident. All-white.
Smell: Young specimens have little to no scent, but with age a rather foul scent may develop.
Spores: Almost round.
Spore color: White
Edibility: Deadly poison!
Habitat: Lives in partnership with oaks and perhaps other hardwoods.
To recognize Amanitas, it’s important to understand how these mushrooms develop, since they go through several changes. All Amanita mushrooms have an initial egg stage, when the entire mushroom is encased in a round “shell” of tissue called the universal veil, plus the gills are initially covered by a sheet of tissue, the partial veil. The lengthening of the stem breaks the universal veil, while the expansion of the cap breaks the partial veil. So a very young Amanita might still be in its egg, or might still have its gills covered.
In more fully-developed specimens, the presence, location, and shape of veil remnants are good clues for identity. The base of the broken universal veil is called the volva and may be cup-like, sheath-like, powdery, or patchy. The top of the universal veil may or may not persist as patches on the cap. The partial veil may persist as a skirt-like ring around the stem, a shaggy margin around the outer rim of the cap, or both, or neither. In A. bisporigera, the volva is cup-like (but may be buried or broken off), there is a ring on the stem but no remnants on the cap margin, and there are only rarely patches on the cap. All of it is white or whitish—although a drop of potassium hydroxide (KOH) on the cap will turn it yellow, an important detail.
Amanita bisporigera Look-Alikes
The closest look-alikes are the other destroying angels. All of them are all-white with white spores, and all share the cup-like volva, the prominent skirt, and the absence or near-absence of patches on the top of the cap. The differences among them are mostly microscopic, although A. bisporigera only grows in eastern North America while western North America has A. ocreata. And A. virosa and A. verna are both exclusively European destroying angels (though some published field guides say otherwise). A taxonomic mess of other species, collectively called the A. elliptosperma species group, share eastern North America with A. bisporigera, but unlike it, none of them turn yellow under KOH.
The other Amanitas are similar in shape—most share the volva and skirt, though few outside the destroying angel group are all-white. Deathcap (A. phalloides) is very similar in shape to the destroying angels, and can sometimes be all-white, though it usually has a greenish cap. Deathcap (or “death cup,” according to some) is a European species that has spread around the world, including to much of the United States, and its name is entirely apt. There are other toxic species in the genus, too. There are some safely edible Amanitas, but many experts recommend never eating any of them, just in case.
The egg stage of Amanitas, as well as the egg stage of the several stinkhorn genera, bear a striking resemblance to many puffballs. The puffball group contains many popular edible species, and while stinkhorn eggs are less popular, many are edible, and some people like them. It’s important to never eat a ball-shaped fungus without first cutting it in half vertically. Puffballs will be homogeneous inside, whereas the “eggs” will show the shape of the embryonic mushroom inside. The difference between an Amanita egg and a stinkhorn egg, when both are sliced, is more subtle, but is evident.
There are also a large number of white or whitish gilled mushrooms that are occasionally confused with destroying angels. Some have volvas or rings (rarely both), though few, if any, have white gills and white spores—cases of mistaken identity almost always involve people not bothering to check major identification clues but simply eating on the basis of assumptions.
Amanita bisporigera Toxicity, Safety, & Side Effects
Destroying angels contain substances in the amatoxin group that ultimately attack the liver, kidneys, and central nervous system. These are slow poisons that can take a week to kill, and yet there is very little doctors can do about it. Very few poisoning victims are saved. That symptoms (initially gastrointestinal problems) don’t show up for up to a day makes diagnosis difficult, because the victim might not realize the mushroom meal was relevant and therefore might not mention it to the doctor. Treatment is further complicated by the fact that symptoms go away for a while after a day or two, which could lull people into thinking the person has recovered. They have not. A liver transplant may become necessary and does not always help.
[i] Kuo, M. (2013). Amanita bisporigera.