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Thursday, September 4, 2014

Poisonous Japanese Mushrooms

In Japan, with mushroom picking playing a role in the whole 'getting back to nature' thing that the Japanese like to do every once in a blue moon, more often than not, it seems, amateur mushroom pickers accidentally pick and ingest mushrooms that aren't all that healthy for themselves and the unfortunate people they offer them to as gifts.

For a list of Edible Japanese Mushrooms, click HERE.

Below, however, is a compiled list of Toxic Mushrooms found in Japan - not all will kill you, some will just make you sick - some for a short while, others forever... so a gathering of information, it would seem, is required.

This is NOT the be all and end all list here - by that I mean you shouldn't put your faith in my work hoping for the best.

It is a best try by myself, however... but you should still find a great book on Japanese mushrooms to assure yourself that what you eat isn't something like what is seen below.

With few exceptions, these mushrooms are perhaps best known by their scientific name, and so I have placed the mushrooms below in an alphabetical list based on their scientific name first, and if there is a common name used by people, it too will be placed via scientific name.

In most instances below, I offer up what the mushroom will do to you if eaten, what it looks like, from cap to stem and gills (under the mushroom cap). I have no idea what the toxic jargon means in most instances, as I have pulled these resources together into one big Japan-related list:

Japanese Toxic Mushrooms

Amanita abrupta
Amanita abrupta - photo by Micahel Kuo
Amanita abrupta, is also also known as the American abrupt-bulbed Lepidella, and grows in eastern North America and eastern Asia, including, surprise, Japan.

Now... let's start with a bang - or not - it is not really known what the edibility is for this mushroom, suffice to say it's not recommended (it gets better on this list - trust me). But, since it is similar to the Asian abrupt-bulbed Lepidell (see below), it is very likely to be a nasty mushroom.

This white mushroom has a slender stem, a cap covered with conical white warts, and a swollen base. The cap has a diameter of four to 10 centimeters (1.6" - 3.9"), and has a broadly convex shape when young, but eventually flattens.

The mushroom lacks a distinct odor.

The mushroom grows on the ground, typically solitary, in mixed conifer and deciduous forests, usually during autumn.

Amanita muscaria
Amanita muscaria is more commonly known as Fly Agaric, or, in Japanese as the Benitengu Take (ベニテングタケ).

Others probably know it better as being the so-called 'magic mushroom', which will take you on a trip through Wonderland and or cause vomiting.

The 'shroom is noted for its hallucinogenic properties, with its main psychoactive constituent being the compound muscimol.

A fatal dose has been calculated as 15 caps. A toxic dose in adults is approximately 6-mg muscimol or 30 to 60-mg ibotenic acid; the typical amount found in one cap of Amanita muscaria.

The Amanita muscaria is a large white-gilled, white-spotted, usually red mushroom, one of the most recognizable and widely encountered in popular culture. Fully grown, the bright red cap is usually around 8–20cm (3–8") in diameter, although larger specimens have been found. The red color may fade after rain and in older mushrooms.

The white spots sometimes wash away during heavy rain and the mushrooms then may appear to be the edible mushroom Amanita caesarea.

The season for fruiting varies in different climates: fruiting occurs in summer and autumn across most of North America, but later in autumn and early winter on the Pacific coast.

Drying may increase potency, as the process facilitates the conversion of ibotenic acid to the more potent muscimol. Conversely, if boiled, it can detoxify the mushroom allowing it to be consumed without the tripping down rabbit holes, but where's the fun in that?

Asian abrupt-bulbed Lepidell
Amanita sphaerobulbosa, commonly known as the Asian abrupt-bulbed Lepidella, was first discovered in 1969, with a habitat encompassing southern Asia, including North and South Korea and Japan.

The species was formerly consider synonymous with the North American lookalike Amanita abrupta (see above), but it is different enough.

The fruit bodies of Amanita sphaerobulbosa are poisonous, and will, if eaten damage the liver.

Poisoning symptoms included the abrupt appearance of violent vomiting, diarrhea and dehydration after a delay of 10–20 hours, but the mushrooms are blamed for the death of two Japanese women in Nagano-ken back in 1978.

Amanita subjunquillea
Amanita subjunquillea, is known as the East Asian Death Cap, found in Asia, including Japan where it is known as Tamagotake Modoki (タマゴタケモドキ).

It looks like a nice mushroom, but it is deadly. There are delayed gastrointestinal symptoms, hepatotoxicity and a 12.5% chance of death.

Its cap is 2-6cm wide, and nearly hemispherical at first, then convex to plano-convex. The cap is brownish-yellow to dirty citrin-yellow to mustard yellow, becoming darker towards the center. The cap's flesh is white.

Its stem is nearly cylindrical, solid, and white to yellowish with yellowish fibrillose scales. The stem's flesh is white

There is an all-white variety, Amanita subjunquillea var. alba in southwestern China, Japan and Northern India (see below).

Amanita subjunquillea var. alba
An all-white variety of Amanita subjunquillea, Amanita subjunquillea var. alba is known in southwestern China, Japan and Northern India.

It's essentially the same as the Amanita subjunquillea (see above), but I'm unsure about its levels of toxicity, just that it is toxic.

Its cap is 2-6cm wide, and nearly hemispherical at first, then convex to plano-convex. The cap is white with white flesh.

Its stem is nearly cylindrical, solid and white, with flesh that is also white.

Clitocybe acromelalga
Clitocybe acromelalga - photo by Daniel Guez.
Clitocybe acromelalga is also known as the Poison Dwarf Bamboo Mushroom, first found in Japan.

It was discovered to be poisonous in 1918, when symptoms occurred three days after eating - after being mistaken for the edible Lepista inversa.

The resulting syndrome of fungus-induced erythromelalgia (formerly Mitchell's Disease) lasted from eight days to five months, although one person exhibited symptoms for three years.

The erythromelalgia is a rare neurovascular peripheral pain disorder in which blood vessels, usually in the lower extremities or hands are episodically blocked (frequently on and off daily), then become hyperemic and inflamed. There is severe burning pain (in the small fiber sensory nerves) and skin redness.

Entoloma rhodopolium
Entoloma rhodopolium, commonly known as the Wood Pinkgill, is a poisonous pink spoored mushroom found in Europe and Asia but is very common in Britain and Ireland, and is found in broadleaf woodlands and on woodland edges.

It is one of the three most commonly implicated fungi in cases of mushroom poisoning in Japan. (The other two are Omphalotus japonicus and Tricholoma ustale). The Entoloma rhodopolium is often mistaken for the edible mushroom, Entoloma sarcopum.

Eating the Entoloma rhodopolium has been known to cause some very unpleasant stomach upsets, with  muscarine and choline isolated as toxic agents.

The mushroom cap is 3-5cm across, convex, flattening and often becoming broad, occasionally with a shallow depression, with a rim slightly incurved and wavy. It is beige, turning paler when dry.

The gills are white, turning pink as the spores mature.

The stem is 4-9cm long and 3-6mm diameter; smooth; white or pale beige, silky; and lacks a stem ring. If you aren't sure what a stem ring is, look at the photo immediately below... you'll see a ring on the stem.

Galerina marginata
Lebrac - Own work
Galerina marginata is a poisonous fungus found in Europe, North America, Asia and Australia.

It is a wood-rotting fungus that grows predominantly on decaying conifer wood.

An extremely poisonous species, it contains the same deadly amatoxins found in the death cap (Amanita phalloides).

If eaten, it can cause severe liver damage with vomiting, diarrhea, hypothermia, and eventual death if not treated rapidly. About 10 poisonings have been attributed to the species over the past 100 years or so, so it can happen.

The Galerina marginatamushroom has brown to yellow-brown caps that fade in color when drying.

The gills are typically narrow and crowded together, a pallid brown when young, becoming tawny at maturity.

The cap reaches 1.7-4cm (0.67"-1.57") in diameter. It starts convex, sometimes broadly conical and has edges (margins) that are curved in against the gills. As the cap grows and expands, it becomes broadly convex and then flattened, sometimes developing a central elevation, or umbo, which may project prominently from the cap surface. with an odor and taste varying from very slightly to strongly like flour.

The stem ranges from 3-6cm (1.2"-2.4") long, 3-9mm (0.12"-0.35") thick at the apex, and stays equal in width throughout or is slightly enlarged downward. Initially solid, it becomes hollow from the bottom up as it matures.

A well-defined membranous ring is typically seen on the stems of young specimens but often disappears with age. Its color is initially whitish or light brown, but usually appears a darker rusty-brown in mature specimens that have dropped spores on it.

Helvella crispa 

Helvella crispa is a mushroom known as the White Saddle, Elfin Saddle or Common Helvel, and has one of those appearances that just screams at the casual eater that if you don't know what it is why are you eating it?

The mushroom is a white version of the black/grey Helvella lacunosa (see below).

The Helvella crispa is easily identified by its irregularly-shaped whitish cap, fluted stem and fuzzy under surfaces.

Helvella crispa grows in grass as well as in humid hardwoods, such as beech, (not so well in resinous ones) along the side of pathways, in hedges and on the talus of meadows. They can be spotted from the end of summer until the end of autumn in Japan, China, Europe and eastern North America.

The Helvella crispa is creamy white in color, 6–13cm (2½"–5") in length, with a cap 2–5cm (1"–2") in diameter. The mushroom looks neat because of the strangely shaped lobes on the cap.

The stem is 3–10cm (1¼–4") long, white or pinkish in color and ornately ribbed.

Its flesh is thin and brittle. The mushroom gives off a pleasant aroma, but is not edible raw.

But is it toxic?

Some people say yes, some people say no. Great - even the professionals are confused.

Yes... you can eat it cooked - but not the stems. If eaten raw, some people have reported some gastrointestinal pains.

But because similar species contain toxic compounds, it is suspected this might, as well.

Helvella lacunosa
Darvin Deshazer - mushroomobserver
The Helvella lacunosa mushroom is also known as the Slate Grey Saddle or Fluted Black Elfin Saddle, and if you saw this in the wild, chances are pretty good you wouldn't think this good to eat.

The Helvella lacunosa is a black/grey version of the Helvella crispa white mushroom (see above).

The Helvella lacunosa is easily spotted by its irregularly-shaped grey cap, fluted stem and fuzzy under surfaces, and is found in Eastern North America, Europe, Japan and China, mostly in alpine and temperate areas under pine, oak and Douglas fir and nearby parkland and lawns.

Fruiting bodies appear in late summer and autumn, though have been recorded in winter in California. It often occurs on burnt ground.

Helvella lacunosa has an irregularly folded or wrinkled cap which may be shades of slate grey to black in color, and measure anywhere from 1-10cm (½"–4"), though usually between 2-5 cm (1"–2").

The stem is wrinkled ringless, about 3–15cm (1"–6") high, and may be white when young and darker with age, though may be any shade of grey.

But is it toxic?

As with Helvella crispa above, some people say yes, some people say no.

Again, you can eat it cooked - but not the stems. If eaten raw, some people have reported some gastrointestinal pains. Similar species contain toxic compounds, so it is suspected this might, as well.

Hypholoma fasciculare
The Hypholoma fasciculare, is also known as the Sulphur Tuft, Sulfur Tuft or Clustered Woodlover, or in Japan as the Nigikuritake (ニギクリたけ).

It is a common woodland mushroom, that is small, but grows well in large clumps on stumps, dead roots or rotting trunks of broadleaved trees in Northern Europe, North America, Iran, Turkey and Japan.

The Nigikuritake is bitter raw, though not bitter when cooked. However, if eaten, can cause vomiting, diarrhea and convulsions. The principal toxic constituents have been named fasciculol E and fasciculol F.

It was sold accidentally at mushroom stalls in Tokyo and Fukushima-ken, which of course created a minor media panic.

The hemispherical cap can reach 6cm (2⅓") in diameter. It is smooth and sulphur yellow with an orange-brown center and whitish margin. The crowded gills are initially yellow but darken to a distinctive green color as the blackish spores develop on the yellow flesh. It has a purple brown spore print.

The stem is up to 10cm (4"in) tall and 1cm (⅓") wide, and is a light yellow, orange-brown below, often with an indistinct ring zone colored dark by the spores.

Omphalotus japonicus
Omphalotus japonicus, commonly known as the Tsukiyotake (月夜茸), is an orange to brown-colored gilled mushroom native to Japan and Eastern Asia.

As part of the Omphalotus family of mushrooms, it has a bio-luminescent fruit body, which means it glows in the dark!

Omphalotus japonicus is poisonous, and if you should eat it, well, you will experience acute nausea and vomiting for several hours. The most common treatment is fluid therapy - to drink and pee it out of your system.

This is one of those mushrooms that is easily confused as an edible mushroom. (Hell, they're all edible - just that some will make you sick or kill you). It is often mistaken for the commonly eaten oyster mushroom (Pleurotus ostreatus).

Omphalotus japonicus was responsible for 31.6% of poisoning cases in Japan between 1996 and 2005—more than any other mushroom.

The fleshy fruit bodies have an eccentric stem rendering the cap kidney- or half-moon-shape and only round when young. The cap is light brown when young and darkens with age, with yellow or pinkish tinges.

The flesh is white and up to 2cm (0.8") thick in the cap.

The thick white gills extend downward and can yellow with age. It is the gills really glow with a whitish light, with reports that the mushroom can be seen 30meters (100') away at night.

The stem is thick and fleshy and can be up to 2cm (0.8") thick and 5cm (2") long.

The mushroom grows on dead beech trees, and is found in mountainous regions of Japan, mostly in September and October - as well as in Korea, China and eastern Russia.

Paxillus involutus
Karelj - Own work (own photo)
The Paxillus involutus is also known as the Brown Roll-Rim, Common Roll-Rim, or Poison Pax, and is found in North America, Europe, India, China, Japan, Iran and Turkey, and was unintentionally introduced to Australia, New Zealand, and South America, where it has likely been transported in soil with European trees.

Once thought to be okay to eat, nowadays it is considered poisonous, as it even killed a German mycologist named Julius Schäffer in 1944, who after a meal developed vomiting, diarrhea and fever. His condition worsened to the point where he was admitted to hospital the following day, and subsequently developed kidney failure, perishing after 17 days.

The Paxillus involutus has been known to cause an upset stomach when eaten raw, but was more recently found to cause potentially fatal autoimmune hemolysis, even in those who had consumed the mushroom for years without any other ill effects.

Basically, an antigen in the mushroom triggers the immune system to attack red blood cells. Serious and potentially fatal complications include acute renal (kidney) failure, shock, acute respiratory failure, and disseminated intravascular coagulation.

It comes in various shades of brown, with the fruit body growing up to 6cm (2.4") high and has a funnel-shaped cap up to 12cm (5") wide with a distinctive inrolled rim and decurrent gills that may be pore-like close to the stem.

The fungus darkens when bruised and older specimens may have darkish patches.

The juicy yellowish flesh has a mild to faintly sour or sharp odor and taste, and has been described as well-flavored upon cooking, but it is not recommended you eat it.

Pleurocybella porrigens
Pleurocybella porrigens is known as Angel Wing, or as Sugihiratake (スギヒラタケ) in Japan.

This mushroom has, for a long time, been considered edible, but in Japan, it has been responsible for quite a few deaths - specifically in 2004 in Japan in nine Prefectures.

A total of 59 people got sick, with 17 of them dying. While those who died already had wonky kidneys... and the average age of the victims was 70, the point is they still died. Death occurred between 13 and 29 days after the onset of symptoms, and the onset of symptoms occurred at most three weeks after consumption of Pleurocybella porrigens.

Having said all that, many people still think this is a safe mushroom to eat - like this guy HERE.

The mushroom grows in Japan and the U.S., and probably other places. As you can see, it looks pretty much like an oyster mushroom - hence the problem.

The mushroom grows on rotting conifer trees, particularly the hemlock, growing in a shelf-like pattern on tree, stumps and logs.

The flesh of the mushroom is thin and delicate (like an angel's wings - which is what you could be wearing if you aren't careful), with a bright white cap when fresh. 

The cap is small, only 2.5cm to 6.4cm (1"-2.5") wide, and have a fan-shape to them, though occasionally you may find one over 10.2cm (4") wide.

There is no stem - if visible, it's a stubby base, thus it lacks a ring, and has no veil.

The gills on the Sugihiratake mushroom are white and close together.

Russula emetica
This image was created by user Bob (Bobzimmer) at Mushroom Observer,
The Russula emetica is also known as the Sickener, Emetic Russula, and Vomiting Russula, and like most things in nature colored red, it's a warning sign to leave it the heck alone.

Found all over the northern hemisphere, it used to be eaten in Russia and eastern European countries, but it is not recommended to be eaten raw, as it does cause some stomach distress. It is supposed to have a very peppery taste, but if parboiled the peppery taste and the toxicity can be removed. If you feel lucky. It is not recommended for eating.

The Russula emetica has a bright red, convex to flat cap that is 2.5cm (1") up to 8.5cm (3.3") in diameter with a shape ranging from convex (in young specimens) to flattened, sometimes with a central depression. Its flesh is white and brittle, but may have some red tinges thanks to the top layer cuticle (skin).

The fruit body can have a slightly fruity or spicy smell to it.

The gills are white to pale cream in color, and are closely spaced.

The mushroom has a smooth white stem measures 4.5-10.5cm (1.8"-4.1") long and 0.7-2.4cm (0.3-0.9") thick, with a smooth, dry surface. It can be stuffed with a cottony pith, or partially hollow. The stem lacks a ring. 

This mushroom grows on the ground in damp woodlands around conifers like pine trees.

Russula subnigricans

Russula subnigricans is also know in Japan as Nisekurohatsu, and is found in Japan, China and North America.

It has been responsible for mushroom poisoning in Taiwan and Japan, with the toxins in the mushroom causing rhabdomyolysis, which basically causes major kidney damage, along with muscle pains, vomiting and confusion, and much more.

The flesh of this mushroom turns pale red when cut - and that's about all I could find on this nasty mushroom.

Stropharia aeruginosa
The Stropharia aeruginosa mushroom is also known as the Verdigris Agaric, and can be found in Japan, Europe and Asia, and can be found on lawns, mulch and woodlands such as hardwoods and conifers between Spring to Autumn.

Can it be eaten? The jury is out here. Some say yes, some say it's poisonous... but while very pretty, with its color, it still looks like a warning to me. I include it here as a 'just in case'.

The 2-6cm (0.8"-2.4") cap is bell-shaped, but has a wonderful deep blue to deep green color, but is slimy and shiny... which should preclude you wanting to eat it.

As it gets older, the color turns a yellowish hue, eventually becoming a brownish yellow.

Stropharia aeruginosa has a partial veil (a covering over the gills or pores to protect the spores until it has matured) that sometimes leaves white remnants on the cap margin and an ephemeral ring or ring zone on the stem.

Additionally, the spore print and mature gills are purplish black--though some forms appear to develop brownish gills.

The gills are attached to the stem, and are whitish to pale gray at first, later purplish gray to purple-black, or brownish.

The stem is 3-8cm (1.2"-3.2") long and 1cm (0.4") thick, and can be both dry or slimy when fresh.

Tricoloma ustale

Trocoloma ustale, is a mushroom found across North America, Europe and Asia, including Japan. It is known as the Burnt Knight because of its color, and grows in association with trees such as the beech.

In Japan, the Trocoloma ustale is known as the Kakishimeji.

This is poisonous mushroom, that if eaten will cause vomiting and diarrhea, not to mention some intense stomach cramps.

The mushroom cap has a reddish-brown color with green tints, and is bell-shaped to conical, measuring 3–10cm (1.2"–3.9") in diameter. The cap does curl inward when young, but straightens as it ages, with the edges becoming lobed and wavy.

The gills (underside) are close together, and are pale yellow when young, turning pale brown with brown spots as it ages.

The stem is cylindrical, measuring 3–9cm (1.2"–3.5") long, and is 1–2.5cm (0.4"–1") thick, being a bit thicker at the base.

The flesh of the Kakishimeji mushroom is white, but browns when bruised.


And that, as they say, is that.

If any of you know of any other mushroom in Japan with toxic features not listed here, or have spotted an error, please do not hesitate to get in touch with me so that I can amend the listing.

Otherwise, happy hunting, and know that if you eat one of these toxic Japanese mushrooms, well, the best advice I can give you is to drink lots and lots and lots of water and get to a hospital with a sample of the mushroom in question.

I am so tired of looking up mushrooms - I think I spent about 20 hours on this... 

Andrew Joseph


  1. Thank you for this list.
    The edible list has mostly specimens I can easily purchase at a grocery.
    What if anything to you know about edible wild mushrooms? especially those that may induce dancing.

  2. Thank you your research. It's a good guide!