Many people have helped us in many ways, which we hugely appreciate. Most importantly, we would like to emphasize that we have 'stood on the shoulders of others'. There are a number of eminent mycologists who have studied the genus Hebeloma and significantly advanced our understanding of it. We specifically mention Duur Aanen, Teun Boekhout, Gilbert Bruchet, Edmondo Grilli, Lexemuel Hesler, Thomas Kuyper, Rolf Singer, Alexander Smith and Jan Vesterholt. Indeed, it was Jan Vesterholt who first got us interested in the genus and worked closely with us until his untimely death in 2010. The works of these scientists have underpinned our work in numerous ways. Even where we have chosen to disagree with their conclusions our respect for their work and the conclusions they drew is undiminished. We have also been hugely influenced by the work of Frieder Gröger, Jules Favre, Robert Kühner, Meinhardt Moser, William Murrill, Charles Peck, Livio Quadraccia and Henri Romagnesi.

We have been flattered by the number of people who have given their time to help us complete this project. They have provided expertise where our expertise or our time was insufficient. In no particular order:

– Edmondo Grilli who has collaborated with us on various aspects of the project, provided us with a huge amount of information with regard to Hebeloma in southern Europe, painstakingly read through our work to help remove errors and also translated numerous diagnoses from Latin into English;

– Machiel Noordeloos has also painstakingly translated a number of diagnoses from Latin (and occasionally other languages) for us;

– Grit Walther has been wonderfully patient with us as she has provided line drawings for a number of species;

– David Hawksworth has also shown huge patience as he has guided us and tolerated our lack of consistency and understanding of many matters nomenclatural;

– Konstanze Bensch and Luis Parra has also helped us with various nomenclatural matters;

– Pierre-Arthur Moreau has been supportive throughout this project, pointing us towards interesting Hebeloma collections, particularly a number that had 'impersonated' Naucoria spp.;

– Vincent Robert has provided amazing support, whatever problems we have had with our Biolomics software (almost always caused by us!);

– Serge Dacos has kept our complex IT system up and running throughout this project enabling us to share information throughout.

We were able to conduct our work as we did because several institutions gave our project a home and access to lab facilities. We are indebted to the Department of Forest Mycology and Pathology of the Swedish Agricultural University of Sweden at Uppsala, the Westerdijk Institute in Utrecht (then CBS-KNAW Fungal Biodiversity Centre in Utrecht) and the Staatliches Museum für Naturkunde Stuttgart. Over time many have contributed to the sequencing effort: Karolina Dukik, Ursula Fürst, Rena Gadjieva, Sigisfredo Garnica, Maria Jonsson, Ceclia Lundström, Delal Öncü, Jessica Petterson, Jessica Schade and, for quite a number of years, Nicole Schütz. Our beta testers of the site have provided feedback and ideas for improvement; we thank Luis Ballester, Linda Davies, Caroline Hobart, Danny Miller, Andy Overall, Andrus Voitk, David Wasilewski and Øyvind Weholt. In addition to providing feedback on the website, Joel and Peggy Horman have helped co-ordinate our efforts in the USA, acting as a local center to which collections could be sent. We would specifically also like to thank Noah Siegel, who has deliberately travelled around the USA, seeking areas of special interest, to collect Hebeloma for us.

Additionally we would like to thank the many - too numerous to list - people who have allowed us to study their interesting collections and allowed us to use their photographs.

A very special thanks to Ann Bogaerts and Petra Ballings, the curators of the herbarium BR (Botanic Garden Meise), for patiently supporting us in our efforts to examine type material of every taxon named worldwide, and helping us in our search to locate this material and arranging the loan of these collections.

Also our thanks to the curators of all the herbaria (fungaria), around the world who have supported, and continue to support, our efforts.

It is clear that we have had enormous help from many hugely talented people and without them this project would not exist. But the errors that remain, despite all the efforts of others to help us remove them, are of course our own and we take responsibility.