Poisonous mushrooms: 8 most dangerous UK mushrooms

They're mysterious, enchanting, fascinating and often beautiful. Yet most of us regard mushrooms and toadstools with suspicion and caution. And for good reason. There are poisonous mushrooms out there, and some of them are deadly.

The worst have sinister names such as deathcap, destroying angel and funeral bell – a warning to steer clear. Here are eight of the most poisonous mushrooms to watch out for in the UK.

Where did the name 'toadstool' come from?

Our mistrust of mushrooms is summed up by the word ‘toadstool’ – a name indiscriminately applied to many species of fungi, well known 'to grow where old rustie iron lieth, or rotten clouts, or neere to serpents dens'. Toads were once considered venomous and so were toadstools and herbalists regarded them to be ‘poysonous damp weeds’ and best avoided.

A deadly poisonous fungus. It’s rare in the UK, but responsible for several deaths in Europe. People have eaten it after mistaking it for chanterelle (Cantharellus cibarius) and magic mushroom (Psilocybe species).

Where: in coniferous pine and spruce woods. It grows on the ground, often among heather and bilberry.

When: autumn.

Appearance: deadly webcap has a dry and matte cap that’s 2.5–8cm in width and reddish brown to orange in colour. Its stem can be orange, red or brown and up to 6–8cm tall. The gills are widely spaced and can also be orange, red or brown but are often paler when young.

Possible confusion: other orange or brown Cortinarius species, chanterelle and magic mushroom.

Toxin: contains orellanine, a powerful mycotoxin. 

The world's most deadly fungus, and it's common in England. Deathcap is responsible for most fatal mushroom poisonings worldwide. 

Where: it grows on the ground in broadleaved woods.

When: summer to autumn.

Appearance: the stem is off white with a bulbous base and can be between 5–15cm tall. Its cap is domed and can grow to an impressive diameter of 12cm. With age, the cap’s dome flattens and can change colour from white or yellow to brown or pale green. 

Possible confusion: common field mushroom (Agaricus campestris).

Toxin: alpha-amanitin, a highly toxic cyclic peptide.

Don't be fooled by its pure white appearance. While rare, destroying angel is a deadly poisonous mushroom. 

Where: it grows on the ground in broadleaved and mixed woodland, especially birch woodland. 

When: late summer to autumn. 

Appearance: a pure white mushroom, which can be mistaken for a button mushroom you’d find in the supermarket. Its stem can range from 7–12cm and has a cap width of 4–8cm. The shape of the cap changes with maturity and can be bell shaped, egg shaped or flat. 

Possible confusion: often mistaken for false deathcap (Amanita citrina), although the main difference is that false deathcap has a yellow tinge to its cap and a sharp smell. It could also be mistaken for Agaricus species, although the gills of Agaricus species are pink, whereas destroying angel has white gills. 

Toxin: amatoxins. 

Fool's conecap is deadly poisonous and contains the same toxin as deathcap mushrooms. 

Where: you could come across this species in your garden. It grows in leaf litter, rotting woodchip piles, sawdust, rich soil and compost. It's uncommon but widespread.

When: autumn.

Appearance: its smooth, shiny brown cap is around 1cm in width and starts off conical, flattening as it expands. The gills are rusty brown. It has a stem ring and the stem tends to be 1–3.5cm tall.

Possible confusion: sometimes confused with the common conecap (Conocybe tenera) which appears on lawns and grassy areas and does not have a stem ring.

Toxin: alpha-amanitin. 

It’s also known as the sweating mushroom, describing its potentially deadly effects. Fool's funnel often grows in fairy rings (naturally occurring circles made up of mushrooms), like the edible fairy ring champignon (Marasmius oreades), so be extra cautious when identifying species during an edible mushroom foray.

Where: lawns, meadows and other grassy areas.

When: autumn.

Appearance: has a white stem between 2–4cm tall. Its cap is funnel shaped and ranges from 1–7cm in diameter. Depending on maturity, the cap’s colour can be white, pale grey or brown. The gills are crowded and can be white or cream in colour. 

Possible confusion: mushrooms that grow in fairy rings, such as the fairy ring champignon. One key difference between this species and fool’s funnel is the gills. The gills of fairy ring champignon are free from the stem and not crowded, whereas fool’s funnel has decurrent and crowded gills. Another mushroom that grows in fairy rings and can be mistaken for fool’s funnel is St George’s mushroom (Calocybe gambosa), however, its main distinction is that is grows earlier in the year, between late April to early July. 

Toxin: muscarine. 

A small but deadly mushroom that grows in clusters on tree stumps and bark. It’s not particularly common in Britain.

Where: mixed or coniferous woods. Grows on dead and decaying wood.

When: summer and autumn.

Appearance: the stem is 3–6cm long and, depending on age, can be pale silvery or dark brown. It also has a small membranous skirt on the stem. Its cap can be 1.5–4cm in width and variable in colour, from pale yellow or brown to orange. 

Possible confusion: often mistaken for velvet shank (Flammulina velutipes), although velvet shank has a black, velvety stem and no skirt. Sheathed woodtuft (Kuehneromyces mutabilis), also called brown stew fungus, looks very similar as well. 

Toxin: amatoxin.

A beautiful but poisonous mushroom that’s uncommon in the UK. It contains similar toxins to those in fly agaric (Amanita muscaria).

Where: broadleaved woods, especially beech or oak.

When: summer to autumn.

Appearance: a taller standing mushroom with a white stem of 8–12cm which is smooth above the skirt but shaggy underneath. Its cap can be 6–10cm wide and comes in varying shades of brown with white spots. However, the white spots should not be used as a distinguishing feature, as they may disappear in wet weather. The cap is also domed initially but flattens out with maturity. 

Possible confusion: the blusher (Amanita rubescens) and more commonly found grey spotted amanita (Amanita excelsa), but both have striations on the upper surface of the skirt which the panther cap does not. The grey spotted amanita also, as its name suggests, has grey spots instead of white. 

Toxin: ibotenic acid, muscimol, muscazone and muscarine. 

This distinctive pure white stemless-toadstool fungus grows in clusters on decaying conifer wood. It’s quite common in the Scottish Highlands and in Cumbria but it’s rare elsewhere. Just appreciate it for its beauty.

Where: it grows on decaying stumps and branches in conifer woodlands.

When: autumn.

Appearance: angel’s wings has an oyster-shaped cap that can be 2–10cm in diameter. The flesh of the cap is white, smooth and thin.

Possible confusion: oyster mushroom, although oyster mushrooms have thicker flesh and generally grow in a different habitat (hardwood in the wild). 

Toxin: pleurocybellaziridine.