home

Amanita genus - Introduction and Identification Key to Common Species in Britain and Ireland

Amanita muscaria - Fly Agaric

Of all the woodland mushrooms and toadstools found in Britain and Europe, the genus Amanita arguably includes not only the best known but also the most notorious of species. The Amanita genus also includes what many people consider to be the most beautiful or stately of mushrooms. Unlike some of the other commonly-encountered genera, the Amanita group contains a manageable number of species in Britain and Ireland: some 50 species of which only about 15 are common and widespread.

If you prefer, you can now go straight to the Key...

A good starting point

If you are new to fungi identification but would like to become good at it, avoid the trap of simply looking through pictures and choosing the 'closest fit'. It may work sometimes but you will have more misses than hits, and what's worse is that it in no way helps you to become really competent. Only by assessing a whole range of features (mycologists use the term 'characters') including physical size, shape, texture, colours, smell and taste plus growing habitat can you compare a mushroom that you have found with the official description accepted as typical for the species. 'Difficult' species may require microscopic examination of spores, but for most the common amanitas we can get by with macroscopic characters (visible without a microscope). Amanita mushrooms generally have very distinctive characters, and for the most part they tend to vary rather less from specimen to specimen than mushrooms in some of the more 'difficult' genera.

The word genus refers to a group with a number of 'general' features in common. Here are some of the features generally associated with fungi in the genus Amanita.

  1. They grow on soil (not directly on wood) but always with mycorrhizal associations (symbiotic or mutually beneficial relationships) with trees. This means Amanita mushrooms will always be in or beside woods or at least hedgerows.
  2. A membranous universal veil covers the entirety of young fruitbodies, creating an egg-like (puffball-like!) appearance
  3. They all have pale (nearly always while) gills that terminate before reaching the stem .
  4. They leave white spore prints.
  5. The cap of an Amanita is easily separated from its stem.
  6. Their caps feel dry rather than slimy.
  7. Many have pieces of universal veil attached to their caps either as warts or irregular patches.
  8. Most but not all have a membranous ring of the stem - remnants of the partial veil that covers the gills when the mushroom is immature.
  9. Most have visible remains of the universal veil attached to the base of the stem, often as a bag-like 'Volvo' or as saucer-like gutter or spiral rings at the top of a swollen or bulbous stem base.
  10. Microscopic characters include either amyloid or inamyloid (but never dextrinoid) spores, and gill tissue that is divergent rather than parallel or interwoven.

Finding the features

Very often, knowing the growing habitat can greatly speed up the identification process, so the first thing to note when you find an Amanita-like mushroom is what kinds of trees are growing nearby. If there are say pines and birches then record both, because it is impossible in the field to ascertain which particular tree a mushroom is connected to. (It's even possible for fungi to create mycorrhizas with more than one tree species simultaneously.)

Base of stem, Amanita pantherina

Immature mushrooms may not display all of the features that become apparent later when the cap has opened up fully.

Finding both immature and mature specimens together is therefore very helpful. Use a knife to dig out the underground stem base one of the mushrooms so that you can check its basal features.

Note whether the bottom of the stem is bulbous or parallel; whether there is a volva and if so what are the colours of the inside and the outside, and whether any volva is flexible or brittle.

Check for any rings around the base of the stem. The stem base shown above is from a Panthercap Amanita pantherina, which has two or more rings girdling the lower stem.

Stem ring, Amanita pantherina

Check to see if there is a stem ring, and if so is it is thin and fragile and/or incomplete or chunky and substantial.

Don't assume it's not an Amanita if there is no stem ring, though: there is a small group of amanitas commonly known as the 'grisettes' that do not have a stem ring.

Some stem rings are chunky and hang downwards in a very neat and distinctive way, as is the case with fresh young specimens of Amanita pantherina, shown above; others remain intact only for a brief period, and if you find an aged specimen its ring might have disappeared almost entirely, although if you use an eyeglass to inspect the upper stem you might at least be able to find a few fragments as evidence that there was a ring.

Don't do taste test on any Amanita-like mushrooms, because there are some deadly-poisonous fungi in this genus and even a tiny taste could be disastrous. One or two species have distinctive smells, especially when they become fully mature, so make a note if there is a particular small associated with your specimen. Crushing gills between (clean!) fingers will make the smell more obvious; alternatively, store a piece of cap in a sealed plastic box for a few minutes, and when you open the box any odour should be very much more evident.

Dichotomous keys present a series of two-option decisions leading ultimately (if all goes well) to the most likely species identification. Thereafter you still need to check the the characters of your specimen against the detailed species description. If the characters do not match,either you have made a mistake while using the key, or the key is imperfect (not unusual) or you have found a species not covered by the key, or (not with this Simple Key but when you are using the most up-to-date and comprehensive of keys) you have perhaps found a species new to science - it does happen!

Simple Key to the 15 Most Common Amanita Species in Britain and Ireland

   

Go to...

1 Stem base not bulbous, without a stem ring 2
1 Stem base bulbous, with a stem ring 6
     
2 Stem scaly, grey to grey-buff, turning darker grey when handled; cap greyish brown with grey veil patches; volva soon collapsing onto stem base; in coniferous woods Amanita ceciliae
2 Stem with scaly, whitish snakeskin pattern, not darkening significantly when handled 3
     
3 Universal veil greyish, irregular patches on grey-brown to orange-brown cap; volval membrane brittle, bag-like, not collapsing onto stem base Amanita submembranacea
3 Universal veil whitish 4
     
4 Stem scaly with a snakeskin pattern; cap yellowish-orange or orange Amanita crocea
4 Stem smooth, cap yellowish-orange, orange, olivaceous grey or brown 5
     
5 Cap cap yellowish-orange, orange or orange-brown; margin striate Amanita fulva
5 Cap grey or grey-brown; margin striate Amanita vaginata
     
6 Cap red or reddish-orange usually with white or yellowish velar warts Amanita muscaria
6 Cap white, cream, olive, greyish, greenish or brownish 7
     
7 Damaged stem base turns pink; cap brownish with grey velar scales Amanita rubescens
7 Damaged stem base does not turn pink 8
     
8 Cap with greenish-olive tints; near oaks or beeches Amanita phalloides
8 Cap without greenish-olive tints 9
     
9 Velar warts white; cap brown; white base bulbous, with volval remains; under hardwood trees, particularly oaks and beeches Amanita pantherina
9 Velar warts whitish; other features not as above 10
     
10 Cap white or pale lemon with white, cream or cream-buff warts; stem base bulbous with a gutter Amanita citrina
10 Cap white; other features not all as above 11
     
11 Cap white, silky smooth; stem ring thin, fragile; stem base with buried sack-like volva Amanita virosa
11 Cap whitish or cream; other features not all as above 12
     
12 Cap whitish, covered in pointed warts; stem clavate, rooting base covered in warty volval remains Amanita echinocephala
12 Cap whitish; other features not as above 13
     
13 Cap cream or creamy buff, with whitish veil patches main in cap centre; base swollen, very short volva Amanita gemmata
13 Cap brownish; volval remains not forming bag on stem base of mature fruitbodies 14
     
14 Cap covered partly or entirely in numerous irregular grey warty patches; robust stem ring grooved on upper surface Amanita excelsa
14 Cap and stem features not all as above 15
     
15 Cap purplish brown, usually covered partly or entirely in purplish-grey velar patches Amanita porphyria
15 Not as above Not in this Simple Key

If you have arrived at 'Not in this Simple Key' it is likely that you have found one of the less common Amanita species that occur in Britain but are not included in this simple key. Some of the rarer species can be seen in our Amanita Gallery and their detailed descriptions are included on pages on this website; however, for comprehensive coverage of all Amanita species currently recorded in Britain we recommend Geoffrey Kibby's specialist key (see references, below), which is available as a printed book.

Reference Sources

Fascinated by Fungi, 2nd Edition, Pat O'Reilly 2016, reprinted by Coch-y-bonddu Books in 2022.

Geoffrey Kibby (2012) The Genus Amanita in Great Britain; self-published; available from Summerfield books and NHBS

Funga Nordica: 2nd edition 2012. Edited by Knudsen, H. & Vesterholt, J. ISBN 9788798396130

BMS List of English Names for Fungi

Dictionary of the Fungi; Paul M. Kirk, Paul F. Cannon, David W. Minter and J. A. Stalpers; CABI, 2008

Taxonomic history and synonym information on these pages is drawn from many sources but in particular from the British Mycological Society's GB Checklist of Fungi.

Top of page...


Fascinated by Fungi, 2nd edn, hardback

Fascinated by Fungi. Back by popular demand, Pat O'Reilly's best-selling 450-page hardback book is available now. The latest second edition was republished with a sparkling new cover design in September 2022 by Coch-y-Bonddu Books. Full details and copies are available from the publisher's online bookshop...

© 1995 - 2024 First Nature: a not-for-profit volunteer-run resource

Please help to keep this free resource online...

Terms of use - Privacy policy - Disable cookies - Links policy