How to identify fungi

, 16 October 2022
How to identify fungi
Angels Bonnet © Dawn and Jim Langiewicz

There are more than 15,000 species of fungi in the UK.

To put that into perspective, there are 59 species of butterfly, 101 mammals, 619 birds, 2,500 moths, and more than 4,000 beetles.

With so many fungi species to choose from, identifying them can be quite a challenge.

Fly Agaric © John Lauper
Fly Agaric © John Lauper

Some are distinctive enough to identify by eye, based on their size, shape, texture, colour – and even smell! There’s no mistaking the Fly Agaric with its spotted red cap, or the Garlic Parachute with its pungent aroma.

But there are hundreds of similar species, so telling them apart soon gets complicated. Fungi are notoriously tricky to ID.

We were sent this fungi photo but were not able to identify it

It’s usually possible to narrow it down to a broad group, or genus, based on visual features: the boletes have pores on the underside rather than gills; the milkcaps exude a creamy latex when damaged; the bonnets are small with bell-shaped caps; the inkcaps dissolve into black, slimy ooze as they mature. Habitat is important too, since most fungi are very fussy about where they will grow, so location can really help narrow down the possibilities.

Spores help too, and taking a spore print can provide further vital clues. To do this you’ll need to remove the cap from its stem and place it gills-down on a sheet of white paper. Cover it with a glass or bowl so it doesn’t dry out, and leave it for several hours or overnight. You’ll end up with the fungi equivalent of a fingerprint created by thousands of microscopic, dust-like spores. The shape of the print reveals the shape and arrangement of the gills, and the colour of the spores can be diagnostic – most are white, cream, pink or various shades of brown.

But often the only way to know for certain which species you are looking at is to examine it under a microscope. Looking at this level of detail requires a lot of specialist expertise as well as equipment, time and patience.

It may not always be possible to know exactly what you’re looking at but if you’re trying to identify fungi, here are some important characteristics to note or photograph:

  • Overall shape, colour and size
  • Smell is sometimes strong enough to be unmistakeable
  • Cap shape eg flattened, bell-shaped, conical, convex, funnelled
  • Cap texture eg smooth, wrinkled, shaggy, cracking, hairy
  • The gills (or lack of) eg crowded, distant, forked, of different lengths
  • Stipe (stem) shape eg cylindrical, bulbous, club-shaped, tapering, rooting
  • Stipe (stem) texture eg shaggy, scaly, smooth
  • Habitat eg grassland, marsh, woodland, or a specific tree

Further challenges

  • Colour can be very variable – many species come in a wide range of shades, and some have very different colour forms. Some colours can be washed out by rain or will fade in sunlight. They can also appear markedly different if wet, compared to dry.
  • Age – many species change dramatically in size and appearance as they age, sometimes quite rapidly. This means individuals of the same species will look different when they first emerge compared to the mature fruiting body, and once past their best they will then start to decay.
Shaggy Inkcap © Mark Monk Terry
Shaggy Inkcap © Mark Monk Terry

A note on foraging

Some fungi are edible, many are toxic and some can be fatal. It’s really difficult to identify fungi and even the experts are cautious, so it’s vitally important never to eat anything you find.

When out looking for mushrooms, please leave them where you find them so that they can complete their life cycle (as fruiting bodies, their function is to produce and disperse spores for reproduction) and so that others can enjoy seeing them. Picking for ID purposes should be kept to an absolute minimum.

We ask that you do not forage for fungi on our nature reserves. For further guidance, the British Mycological Society has produced a useful code of conduct britmycolsoc.org.uk/field_mycology/conservation/code-conduct

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Comments

  • Simon Carter:

    Very helpful. Thank you Charlotte.

    20 Oct 2022 10:47:00

  • Sheppy Shepherd:

    I was gratified to find some tiny yellow fungi growing in my small front garden. I have no idea what they are but something has been nibbling at them. I hope it enjoyed the meal and survived the experience.

    20 Oct 2022 11:04:00

  • Mrs Irene Bennett:

    Excellent article on fungi with wise advice to leave them well alone.

    20 Oct 2022 11:12:00

  • Martin Derham:

    Just wondered why the article suggests taking a spore print when you ask people to leave fungi where they find them to complete the lifecycle. Just feel it might encourage people to think “I am going to try to take a spore print” which is the opposite of what you want.

    20 Oct 2022 11:36:00

  • Helen McNeil:

    What a pity our pharmacists aren’t trained like their French counterparts to identify fungi and advise of their gastronomic interest, but then we Brits don’t go foraging so readily!

    20 Oct 2022 13:42:00

  • JENNIFER BROMFIELD:

    I love identifying fungi. I will always remember finding an Earthstar fungus under the hedge in our front garden in Woodingdean.

    20 Oct 2022 19:39:00

  • Stephen Cooper:

    Thank you very much for a very interesting article. I too wish our pharmacists could help – I would love to know if I can eat the “field Mushrooms” (if that’s what they are) in our garden/field!

    20 Oct 2022 21:06:00

  • Jill:

    Thank you foryourhelpfull info on bird songs and fungi.

    21 Oct 2022 10:08:00

  • Mike Lushington:

    I note that French Pharmacists are taught to identify fungi. My wife was an Australian pharmacist and she was also trained in mycology. We had great fun foraging and had good meals of edible fungi in Australia, UK and Europe. Unfortunately she died this year and so I am left to have them from the Supermarket.

    21 Oct 2022 17:06:00

  • Justine Sayer:

    Very informative thank you – the comparisons made against fungi to butterflies and moths etc really puts nature into perspective. Thanks again. Lovely reading and visuals.

    21 Oct 2022 19:00:00

  • Alan Morton:

    More pictures would be great & really useful as a reference :-)

    24 Oct 2022 09:15:00

  • Sussex Wildlife Trust:

    With 15,000 varieties, there is a limit to how helpful we can be, but you might find this a helpful resource: https://www.wildlifetrusts.org...

  • Meg:

    Very interesting and informative. Thank you.

    26 Oct 2022 10:11:00

  • Jean Wright:

    Just what I was looking for to pass on to my adopted grandchildren. Many thanks. Jean

    16 Nov 2022 11:26:00

  • Jill Cousin:

    A concise & extremely useful article – thank you .

    10 Oct 2023 06:48:00