The fungi you need to know: How to pick a wild mushroom that won't poison you

Falling in love, they say, is like eating an unknown mushroom. You never know it's the real thing until it is too late. This summer is already producing crops of wild mushrooms – ceps, chanterelles, summer truffles and other delicious kinds, which are appearing in profusion in the warm, damp woodland soil.

More than 100 kinds are good to eat and reasonably easy to recognise – though only a dozen or so are collected commercially. Why don't we gather the others?

You know the answer – because of the danger of mistaken identity. Just as there are plenty of delicious species, there are also lots of poisonous ones. Some may result in nothing worse than a stomach upset, but a few of them are killers. Their best-known recent victim was Nicholas Evans, the best-selling author of The Horse Whisperer, who nearly died after eating a quantity of the quaintly named deadly webcap. Victims of the more distant past have included Emperor Claudius (of I, Claudius fame), Pope Clement VII and the Habsburg Emperor Charles VI, whose untimely demise, after tucking into a dish of sautéd death caps, led to the War of Austrian Succession.

Fear of poisoning began in ancient times. Some of the classical writers believed that nearly all mushrooms were poisonous. One suggested that they somehow store pollutants from the soil, while another suggested they are infected with the noisome breath of serpents. Folklore is full of tips on how to tell the good kinds from the bad – and all of them are rubbish. One sign of toxicity, they say, is a bright colour, especially red, and also an evil-looking pointed cap. Poisonous mushrooms, they say, will turn a silver-spoon black. Supposedly mushrooms that grow on wood are safe. At least one isn't. Its playful name is "funeral bell" and it is a killer. Perhaps the most persistent of all these fables is that, if you can peel the skin off a mushroom, you are safe. No you aren't. The appropriately named death cap peels beautifully (and, apparently, tastes quite nice). There is only one reliable way to tell if a mushroom is good to eat – identify it correctly. If there is a shred of doubt, don't eat it. Better safe than sick.

Serious cases are rare, but close encounters with poisonous fungi seem to be rising. Last year the National Poisons Information Service received 209 enquiries from GPs compared with 123 the previous year. Half of them concerned children. Toddlers are known to eat little brown toadstools on the lawn, some of which are toxic. Many other enquiries are from people who overdosed on "magic mushrooms". Of 114 referred enquiries in Northern Ireland between 1997 and 2000, only 10 were the result of eating a mistakenly identified mushroom for supper.

It all suggests we Brits are fairly cautious in our mushroom-eating habits. For the more adventurously inclined, there are reliable, well-illustrated books aimed at separating the delicious from the dreadful. Expert-led eco-foraging forays are, well, mushrooming, and there are weekend courses for getting to know wild mushrooms better. As you gain experience you can branch out and discover the delights of mushrooms that few people dare to eat – grisettes, milkcaps and brittlegills.

The mushroom season is just beginning. Given a warm, moist autumn it may last until November. Collect sensibly, don't pick everything in sight, and remember the Forager's Warning: You can eat any wild mushroom. But some you will only eat once.

Uncomfortable pairings

All too many delicious mushrooms have a poisonous or nasty-tasting lookalike – as though they were put there to test us. Here are just a few examples. Never eat any of these unless you are sure you know the difference

Cep or Penny Bun, Boletus edulis

A chubby mushroom, shaped like a bread roll, with pale grey or yellow pores. The most versatile mushroom of all, it is equally good fresh, dried or pickled.

Bitter Bolete, Tylopilus felleus

Very similar, but with pale pinkish pores. It has an intense bitter taste and even a small portion of this one will ruin a dish of ceps. Although rarely found on forays, it sometimes turns up among imported ceps.

Fairy ring champignon, Marasmius oreades

The mushroom that produces those mysterious dark rings on lawns and sports pitches. It is usually dried and used as a flavouring after discarding the tough stems.

Fool's funnel, Clitocybe rivulosa

Unfortunately, this one also forms rings, often on the same lawn. It has a frosted white cap, like icing on a bun. Also called the sweating mushroom, its symptoms resemble a bad case of the flu.

Field mushroom, Agaricus campestris

Silky white cap, turns pink when bruised. It smells, well, of mushrooms. Grows in fields, especially where there are horses.

Yellow-stainer Agaricus xanthodermus

Matt white cap, turns yellow when bruised, smells of ink. Grows in woods and gardens. If in doubt, cut the base of the stem; it will turn bright yellow.

Symptoms include tummy ache. That inky smell is phenol, also known as carbolic acid.

Morel, Morchella esculenta

Resembling a honeycomb on a stalk, the morel has a strong earthy taste and is wonderful with scrambled eggs. Usually found in the spring. Don't eat them if they grow near a busy road or car park. And always cook them first.

False morel, Gyromitra esculenta

Looking like a brain on a stick, this poisonous mushroom tastes delicious. It is sold commercially in Finland and Spain, though with a warning not to touch it – the poison is dissipated by cooking.

Parasol mushroom, Macrolepiota procera

A stately mushroom with shaggy scales and a tall stem with snake-skin markings. Particularly good when stuffed with sage and onion.

Shaggy Parasol, Macrolepiota rhacodes

Once thought to be edible, it has caused stomach upsets. It is similar but smaller than the true Parasol mushroom. So one solution is to collect only large ones.

Chanterelle, Cantharellus cibarius

True chanterelles are the colour of egg yolks and have a wholesome, fruity smell. Instead of gills, they have simple folds running down their stems. Their slightly peppery taste makes excellent mushroom risotto.

Jack o'lantern, Omphalotus illudens

A poisonous mushroom that glows faintly in the dark. It shares the orange colour and shape of the chanterelle but has true gills, not folds. More common is the false chanterelle, which is not poisonous but tasteless.

Paddystraw mushroom, Volvariella volvacea

Not found wild in Britain, it is readily cultivated and sold fresh or dried, especially in Asian outlets.

Death cap, Amanita phalloides

Unfortunately, this fatally poisonous mushroom shares the most noticeable feature of the paddystraw mushroom: the white cup or volva at the base of its stem. This has led to deaths in places where the paddystraw is sought.

The blusher, Amanita rubescens

This common, pink-bruising mushroom with grey scales is very tasty – if you can beat the slugs. Unfortunately, it belongs to a group that contains dangerously poisonous species and so is definitely one for the experts.

Panther cap, Amanita pantherina

Smaller and neater than the blusher, this is easy to confuse with it. Panther cap poisoning produces sickness and hallucinations, so you might see dancing dragons as you gasp and retch.

Recommended reading:

'Mushrooms: River Cottage Handbook No 1' by John Wright (Bloomsbury); 'How to Identify Edible Mushrooms' by Patrick Harding, Tony Young & Gill Tomblin (Collins)