Author Interview: Jens H Petersen and Thomas Læssøe, Fungi of Temperate Europe (2-Volume Set)

Authors,  Thomas Læssøe and Jens H Petersen have spent the last five years creating the wonderful two volumes set: Fungi of Temperate Europe. They have taken the time to answer our questions about this monumental and daunting project.

Could you tell us a little about your backgrounds and how you got interested in mycology?  


We both dived into the mycological forest sometime in the late seventies and subsequently studied mycology at the Danish universities of Aarhus and Copenhagen. Since then, we have both tried to make mycology accessible to a broader audience, both through countless excursions and mycology courses and through books and photography (the present work includes photographs from the very first years of this 40 years period). Check also the book, The Kingdom of Fungi by Jens H. Petersen.

Two volumes, totalling over 1,700 pages must have a been a considerable undertaking; can you let us know a little of the process and how long it has taken for this book to come to fruition? 


We have worked with the books for five years. Firstly, we made a long list of taxa we wanted to include and Jens started to develop the first identification wheels. We had the first dummy layout in summer 2015 and made the first version of the wheels for the Basidiomycota during autumn 2015. The asco wheels and the layout of the species pages followed in 2016. By summer 2017 we had a layout ready, but without text.

While Jens did wheels, layouts and photo-shopping Thomas produced the Danish texts online in our Danish Fungal Atlas database ( and these were more or less finished during spring 2017. Then followed the long process of proofreading texts and editing them into the layouts. By summer 2018 this was finished and we started to do the translation into English. Fortunately, we had a couple of skilled UK copy editors who corrected mistakes and improved the language. The English edition was ready in April 2019.

The whole process was terrifying with respect to size which no one involved realised before they were deeply immersed in the books. The solution was to keep a tunnel vision most of the time, and just try to finish the one little piece of the puzzle in question and only on rare occasions emerge to the surface to look around and consider the distance to the goal line.

Who do you envisage using Fungi of Temperate Europe – what readership is it aimed at? 

Everyone with a basic knowledge of fungi.

The book uses ‘form group’ to identify and present the fungi rather than exclusively strict taxonomic groups; what influenced you to use form groups and fungi wheels?  



Scientists using modern DNA methods tend to split fungal genera into more and more narrow entities. As these are based on base pairs they may be absolutely devoid of morphological characteristics and thus impossible to work with for non-scientists. Thus any attempt to approach fungal identification in a strictly phylogenetic way will fail. It is for example impossible to construct a well functioning identification key to genera of fungi (we have been there several times, tried that and failed). This lead us to develop the multi-access computer key MycoKey ( and now later to try to convert the learning from MycoKey into book form.

What was your most surprising discovery whilst researching Fungi of Temperate Europe?  

That fungi are difficult but beautiful.

What is the biggest challenge when studying fungi?  

That fungi are mostly invisible to the naked eye unless they develop fruitbodies and when they do, the morphological plasticity of these fruitbodies is baffling. Thus good pictures are often worth more than detailed, lengthy descriptions.

After such an endeavour you surely deserve a rest, but have either of you got any future projects planned that you can tell us about?  


We are working on a book with new identification keys to Danish Basidiomycota. The overall structure of this will be built on the form group identification wheels from the present work but the species keys will be dichotomous, analytical keys with lots of illustrations. We believe that the two projects will supplement each other.

We would both like to dive deeper into the world of Ascomycota and possibly return to tropical mycology.

Fungi of Temperate Europe (2-Volume Set)
Aug 2019 £74.99 £94.99
The culmination of five years work from authors, Thomas Læssøe and Jens H Petersen




UK Fungus Day 2017

King Bolete - Bernard Spragg
Also known as the Cep or Penny Bun, the King Bolete is widely distributed throughout Europe. Image by Bernard Spragg via Flickr Creative Commons (CC by 2.0).

What is UK Fungus Day?

The 2017 UK Fungus Day will take place on Sunday 8th October. This event is organised to raise awareness and educate the public about the importance of fungi, and also to bring together scientists, artists and naturalists who are involved with fungi as part of their work or hobby.

On the 8th October a range of public engagement activities involving science and the arts will run concurrently across the UK and will include fungal forays and talks by scientists as well as craft workshops and events for children.

What have fungi ever done for us?

The fungi are a group of eukaryotic organisms that include the yeasts, molds and mildews, as well as the larger mushrooms and toadstools that we more typically associate with the name. They are abundant worldwide and play a vital role in ecosystem processes. Most trees and plants rely on a symbiotic relationship with fungi around their root systems whereby the fungi provide key nutrients to the plant, in return receiving sugars that are produced by the plant’s photosynthesis. They are extremely important for the recycling of dead matter and help to make vital nutrients available for new growth. Humans also rely on many types of fungi for food or medicine – imagine a life without bread, beer or penicillin. A certain type of fungi is even used to flavour chocolate!

How do I get involved in Fungus Day?

On the 8th October a series of events will be held around the UK at botanic gardens, museums, science centres, universities and nature reserves.

Interested in the science and biology of fungi? Why not head along to a talk by an expert or researcher? Want to learn to identify mushrooms and toadstools in the field? –  join a fungal foray and see the spectacular specimens that are popping up everywhere this autumn. Are you into arts and crafts? There’s even something for you – go out and meet some of the artists that are inspired by (or even use!) fungi in their work.

To find out what is happening near to you, check out the interactive map on the UK Fungus Day website. Or, if you are interested in organising your own event, download the Fungus Day complete resource pack.

Take a look at our blog on Planning a Fungal Foray for some tips on planning your own ID expeditions.

Can you recommend some good fungi books and field equipment?

Below you will find a great selection of fungi field guides, as well as some other interesting reads. For those who want to take their identification skills to the next level, we have also included a selection of hand lenses and microscopes.

The Fungi Name TrailThe Fungi Name Trail: A Key to Commoner Fungi
FSC | Pamphlet

A key to some of the more easily recognised fungi present in Britain’s woods and fields. The name trial takes you through a series of yes or no questions to help you identify your fungi.


Collins Fungi Guide

Collins Fungi Guide: The Most Complete Field Guide to the Mushrooms and Toadstools of Britain & Ireland
Stefan Buczacki | Paperback

Nearly 2400 species are illustrated in full colour, with detailed notes on how to correctly identify them, including details of similar, confusing species.


Mushrooms and Toadstools of Britain and EuropeMushrooms and Toadstools of Britain & Europe, Volume 1
Geoffrey Kibby | Hardback

Volume 1 illustrates the non-agarics including, puffballs, stinkhorns, earthstars, coral fungi, polypores, crust fungi, chanterelles, tooth fungi, boletes, Russula and Lactarius.



Roger Phillips| Paperback

Set to become the essential illustrated mycological encyclopedia for the next 25 years, this book is also clear, user friendly and will appeal to a wide range of readers. Unsurpassed in both illustrative and descriptive detail.


Peter Marren | Hardback

Written in Marren’s inimitable style, Mushrooms provides a refreshingly candid view of the diversity of fungi and our relationship with this intriguing group, exploring such subjects as the naming of fungi, their importance in natural ecosystems and fungal forays.


Other recommended fungi books:
The Mushroom at the End of the World
Mycorrhizal Planet
Teaming with Fungi
Where the Slime Mould Creeps

Opticron Hand Lens

Opticron Hand Lens 23mm 10x Magnification
Excellent and affordable 10x lens.


Belomo Triplet Loupe

Belomo Triplet Loupe Hand Lens
High quality triplet lens.



Dino-Lite AM4113T

Dino-Lite AM4113T USB Digital Microscope
USB microscope for viewing and saving images on your computer.



Mushroom Identification: Pro Tips from Top UK Mycologists

Photo: Leccinum holopus by Geoffrey Kibby, from British BoletesSeptember is upon us with morning mists and a slight chill in the air… it must be mushroom time! Around this time of year, books on mushroom identification and natural history appear with almost as much certainty as the fungi themselves. Two of our favourite mycologically-minded authors, Peter Marren and Geoffrey Kibby, give some useful and interesting tips for the keen mushroom hunter.

(Note: we cannot stress strongly enough the caution with which you should approach mushroom identification. Some mushrooms are edible, but some are deadly, and identification can be very difficult. As Geoffrey Kibby says below, if in doubt, throw it out!).

Mushrooms - Peter MarrenFirst up is Peter Marren, whose forthcoming book, Mushrooms, is the first in a new series of natural history publications, the British Wildlife Collection

Peter Marren’s tips on mushroom identification for the beginner

There are an awful lot of fungi – 2,400 species in the latest field guide and that’s just the larger ones. Fortunately, perhaps, most of them are rarely seen. There are only about a hundred really common ones, and they are the ones you need to know.

  • Forget about the ‘little brown fungi’ for now. Try getting to know an accessible group such as the waxcaps or the boletes, or the puffballs and their ‘relatives’. It will teach you a lot about the differences between species and the places to look for them.
  • Join a fungus foray organised by your local fungus group or wildlife trust, or, better still, attend a weekend course at a field centre. Direct contact is better than books.
  • Picking mushrooms does no harm. They are not plants but the fruit bodies of an organism living in the soil or in wood. Apples on the tree, as it were. And you will need to bring back specimens of fungi that are impossible to identify in the field.
  • Gathering and cooking wild fungi is great fun, especially as shared fungus feast. But never eat any that you cannot identify with confidence. There are a lot of poisonous fungi out there.
  • For fungi an x20 magnification hand lens is useful. At some point the dedicated forayer will need a microscope, but that, as they say, is a whole new ball park. Or playing field, as they are also known.

Peter Marren on recommended books for mushroom identification…

There are not many read-through books about fungi. I enjoyed Patrick Harding’s Mushroom Miscellany, a series of short chapters on all aspects of fungi, and the New Naturalist volume Fungi by Brian Spooner and Peter Roberts is all-embracing and thorough, but not for the faint-hearted. From Another Kingdom, published by the Royal Botanic Garden Edinburgh is an informal seminar on matters mycological, including ‘fungal monsters in science fiction’. The best field guide in my opinion is still Marcel Bon’s Mushrooms & Toadstools, first published back in 1987, although it needs updating. Paul Sterry and Barry Hughes’ Collins Complete Guide to British Mushrooms and Toadstools has the best colour photographs.

…and on his new book, Mushrooms

Mushrooms is my personal take on the world of fungi in Britain, about the pleasures of searching for mushrooms and toadstools, and why they matter. I have written it as a narrative, in current TV parlance as a ‘journey’, beginning with the extraordinary diversity of fungi and the ways in which they exploit the natural world to the history of the fungus foray and the controversy over gathering wild mushrooms for the pot. In the process I zoom in on the nature of names, both Latin and English, at the places which hold the greatest diversity of fungi, and our attempts to conserve rare and vanishing fungi. It is, I hope, a refreshing and amusing look at this ‘third world’ of life, written without jargon and in lively style. I hope it can be read with pleasure by anyone. It is full of lovely colour photographs.


The Genus Amanita in Great BritainNext up, Geoffrey Kibby, whose new photographic identification guide to the Genus Amanita is the fourth in a series of full colour fungi identification monographs, and is out now. In the following article Kibby discusses the finer points of mushroom identification:

The joys and tribulations of fungus identification

Firstly, let’s be quite clear: there are an awful lot of fungi! Just including those generally referred to as the larger fungi – those just a few millimetres across all the way up to species that can reach a metre or more – there are around three thousand species recorded in Britain.

Whether we call them all mushrooms, as the Americans tend to do, or toadstools as we often do in Britain, they form a huge and amazing array of species. The terms mushroom and toadstool are of course very vague with no actual specific scientific meaning, encompassing both edible and poisonous species.  With such a large number of species to choose from, identification can be both difficult and frustrating, and if edibility is a factor then obviously getting a correct identification is even more important; a mistake can be, and sadly has often been, fatal.

General field guides are the usual starting point for most amateurs just starting out in mycology (the proper term for the study of fungi) but there is an obvious problem here: the number of species included. Many guides have just a few hundred species that may not cover enough of the species you will find. More comprehensive ones usually have about 1000 to 1500 species and are accordingly more useful. The largest guide yet produced (Collins Fungi Guide by Stefan Buczacki with beautiful watercolour paintings) has around 2,400 species, but that does not of course guarantee that you will produce a correct identification. Indeed too many choices might be as confusing as too few. Then there is the choice of whether to get one with photographs or paintings (both have their different advantages).

Many species can only be distinguished with certainty by using a microscope to examine their spores and other microscopic structures, or by the application of specific chemicals to produce colour reactions. More technical monographs are needed for these.

A field guide can only take you so far and show you a representative sample of a particular species. Fungi vary much more than most organisms and you will need to learn them in all their many and varied forms before you can confidently say you know a species well. The best way to learn is to get a good guide and then take it along on an organised fungal walk (or foray as they are usually called). Here you will usually be led by an experienced expert who can show you first hand the important features of each species as well as their particular ecology. The latter can be vital in fungus identification. Many fungi grow in association with specific trees or other plants and knowing this can help you to identify or even predict the species you may find.

By going on regular fungus walks, or perhaps joining a longer course over a weekend or a week you will gradually learn to recognise the commonest species which you will see on almost every walk and start to learn some of the more uncommon species also.  Almost every county has a mushroom group and there are also larger, country-wide mycological societies such as the British Mycological Society or the Association of British Fungus Groups. These organisations can put you in touch with your local group as well as organising forays and workshops of their own and producing useful publications. The journal Field Mycology, which I edit for the BMS, is aimed at the beginner all the way to the specialist and mainly deals with larger fungi.

Comparing the actual fungi you find with the photos or paintings in your field guide will soon show the value of owning more than one guide. Each guide may have a different list of species and some will have better illustrations of a particular species than another. Most mycologists soon build up a small library of picture books! Using a digital camera to photograph specimens or trying your hand at making paintings of them and building up your own catalogue of illustrations is highly recommended also. Once you are more confident of the commoner species then there are a number of more specialist works, usually dealing with a specific group of fungi and this is often the best way to really make progress, by concentrating on a particular group which you find especially attractive or interesting.

British Boletes: With Keys to Species - Geoffrey KibbyI would certainly recommend the boletes as an ideal group to begin with. They are often large, very brightly coloured and with good field characters and include a number of excellent edible species. Almost all the species can be identified in the field with a little experience and a good reference work. After 48 years of studying fungi the boletes remain among my favourites and many other mycologists will say the same. The book on boletes which I have produced, British Boletes, aims to provide easy to use keys based mainly on field characters and photographs of the vast majority of the British species. My books tend to focus on the most widely studied and popular groups of fungi. Hence I have titles covering Russula (The Genus Russula in Great Britain), Agaricus (The Genus Agaricus in Britain) and my most recent work The Genus Amanita in Great Britain. All are available from NHBS. Further titles will be forthcoming in the next few months, in particular one on the genus Lactarius, commonly called Milkcaps and further down the road an illustrated field guide to 1200 species of larger fungi.

Geoffrey Kibby’s top tips for safe mushroom identification

Many people come into mycology via a desire to try eating something a little more exotic than the shop bought mushroom. There are many edible species and they can have tastes and textures quite unlike the cultivated species. Hunting for edibles can be a wonderful experience but there are several rules to follow if your hunt is to have a happy outcome:

  • Make sure you are allowed to collect, many woodlands or parks have restrictions on picking.
  • Obey any local rules on how many you can pick and try to leave some for others to admire, don’t ‘vacuum’ the woods of everything you see.
  •  Collect only specimens in good condition; old or rotten specimens will not make a good meal and can cause serious stomach upsets.
  • MOST IMPORTANT OF ALL: you must be absolutely sure of your identification, some mushrooms are deadly and a mistake can quickly become fatal. If you are a beginner then always get the advice of an expert. Stick to a few, unmistakable species. IF IN DOUBT, THROW IT OUT.
  • Always keep aside a specimen of anything you collect to eat and if it is a species you have not eaten before then sample just a little—even good edibles can cause upsets in some people (many people can’t eat strawberries or nuts for example).

Mycology, or mushrooming, can appeal on many levels, from the simple pleasure of seeing strange and wonderful organisms to the intellectual challenge of trying to identify them and understand their intricate life cycles. But the starting point is, and always will be, a good book!

And finally… hand lenses to help with mushroom identification

Last week we published a blog post with advice on purchasing a hand lens, plus a useful comparison chart showing the various lenses you can buy from NHBS. 

Read The NHBS Guide to Buying a Hand Lens



Mycologist Geoffrey Kibby on childhood discoveries, woodchip mulch, and his long time passion for the genus Russula

British Boletes: With Keys to Species jacket imageGeoffrey Kibby, senior editor of Field Mycology, and author of two recent best-selling photographic keys to fungi – British Boletes and The Genus Agaricus in Britain – talks about how childhood discovery in a woodland wonderland led to a life spent mushrooming…


What first attracted you to the curious world of fungi, and what are your mycological credentials?

I have been mushrooming for over 45 years; as a boy of 13 I was convalescing from some surgery and was staying in a cottage very close to the Queen’s estates at Sandringham in Norfolk. Opposite the cottage was a large area of fenced-in woodland with “Private, property of HM the Queen” on a gate. Like any self-respecting schoolboy I completely ignored the sign and climbed over the fence and into what I can only describe as a wonderland. A damp, mossy conifer wood, dripping with lichens and ferns and with fungi everywhere. I still remember the first fungus I was ever consciously aware of, a beautiful, small and intensely violet toadstool (Laccaria amethystea) and I thought I had never seen anything so amazing, so magical. I soon purchased my first book, the Observer’s Book of Mushrooms, and quickly realised that I needed a bigger book! I have been collecting and writing about them ever since.

For most of that 45 years I have been a member of the British Mycological Society and for the last 12 years have been the Senior Editor of the journal Field Mycology which deals with all aspects of mycology (the study of fungi). For about six years I lived in the USA and was at one time the President of the New Jersey Mycological Association. I have published numerous books on fungi including general field guides as well as more specialist monographs.

Your recent publications on British Boletes and The Genus Agaricus in BritianThe Genus Agaricus in Britain jacket image have become instant bestsellers. Who are they aimed at and what can the reader expect from them?

My specialist books are aimed at the enthusiastic amateur all the way up to the specialist – usually people who realise that the popular field guides are not sufficient to tackle some of the larger or more difficult groups of fungi. I have tried to make them more user-friendly than the traditional identification keys, often using a synoptic system whereby the reader only has to decide on 6 or 7 principal characters before attempting to key out the particular species. My keys include lots of illustrations to aid the reader in making these decisions. In some cases a microscope is required but the techniques needed are not that difficult and of course a microscope opens up a whole new world of wonderment in all areas of natural history, not just in mycology!

Generally, what part do fungi play in the world’s ecosystems?

Without fungi to digest and break down the decaying organic matter in our woods and fields the world would soon be swamped in enormous depths of fallen twigs, leaves and other debris. Most trees are dependent on fungi and form specialised symbiotic relationships with them, they cannot grow well without them and vice versa. Other fungi of course are parasitic and attack other organisms (including ourselves…) and many others have strange life cycles which we scarcely understand at all and this all adds to our fascination with them.

We’re in fungi season now – to what extent are there annual changes in the fungi ‘populations’ throughought the UK, and is there any way in which fungi acts as an indicator of wider environmental changes?

In recent years there have been enormous ‘invasions’ of new fungi and as the climate has changed we have seen corresponding changes in the way fungi behave and fruit. Our penchant for covering the world in woodchip mulch has paved the way for numerous exotic species to come into the country. Some species have spread to every British county, using this newly invented habitat, within 5 years of their first discovery, an amazing colonisation by any standard.

Increased annual temperatures are affecting the way in which fungi fruit; species which formerly fruited only in the autumn are now often fruiting twice a year in both spring and autumn. Others which were specialists in fruiting only in the spring, such as the common and deliciously edible morel have been appearing as late as November or even January!

Do you have a favourite mushroom?

Almost an impossible question to answer, but I certainly have favourite groups. The boletes have been a favourite since my childhood as they are for many other mycologists. Their large size and often bright, exotic colours are very appealing and they are relatively easy to identify also, hence my recent book on the subject. I also have a long time passion for the genus Russula, a sometimes very difficult group with around 170 species in Britain, often of very bright colours once again and very common everywhere. I am putting the finishing touches to my ‘magnum opus’ on that group as I write this.

Can you describe a particularly interesting species, or feature of a species of a mushroom found in the UK?

Many fungi form associations with other fungi, some of which we are still in the process of discovering. Many boletes for example, particularly in the genus Suillus form associations with a group of fungi called Gomphidius. Each species of bolete seems to latch onto a particular species of Gomphidius, very specific, and we don’t really know what is going on, although the best guess is that one partner is sort of hitching a ride on the other, tapping into its associate’s ability to obtain nutrient from the particular conifer with which it grows, without having to do the work itself.

British Boletes: With Keys to Species internal imageThere is some great photography in the keys – I guess a mushroom is a perfect still subject for the nature photographer – is photography a hobby of yours that has grown from your work?

I have been photographing for as long as I can remember and using fungi as subjects was a natural extension of this. I now teach digital photography and the use of Photoshop to enhance and edit photographs as part of adult education courses at local colleges. Fungi are ideal subjects since they don’t run away or even sway in the breeze as wild flowers do, and of course their strange shapes and colours are wonderful subjects to try and capture.

I went mushroom hunting recently and always ended up way off a positive identification. Given the dangers of mistaken-identity, what advice would you give the amateur fungi hunter? 

Start small: learn to recognise the basic groups where possible, that is half the battle. Go on as many guided mushroom walks as possible and learn from experts in the field – there is no substitute for that. Field guides can only take you so far and cannot show you all the many variations that fungi are capable of. My favourite saying is that “mushrooms don’t read the books!” Meaning that they don’t always conform in size and appearance to the illustrations in the book, they vary enormously as they age. Get as many books as you can afford, each will offer some extra information and pictures that another might lack. Finally, never, ever eat a fungus you are not confident of. All mushrooms can be eaten once but sometimes not twice……the history of mushrooming is filled with people who have eaten and become very sick or even died from making an error in identification.

On which cautionary note…

Geoffrey Kibby’s keys are available now from NHBS:

British Boletes: With Keys to Species

The Genus Agaricus in Britain