The preparation of this checklist has involved many sources and help from numerous individuals and institutions. I thank all those who contributed to this work and would especially like to acknowledge the following: Alan F. Baker of A.F and S. Baker, Pat Baker of Baker Ross Ltd., John Morgan of Helios, Tony Pinkus of Ainsworths and Roger Barsby of Weleda for providing funding for part of this project; Roger van Zandvoort, for supplying the list of names from his Complete Repertory in electronic format and for his continuous help and support over the years; Farhad Madon and Rosemarie Rees for help with setting up the nomenclature database; Tony Scott for re-structuring the nomenclature database; David Sutton for the bibliography database; Sinead O'Hara of The Royal London Homeopathic Hospital for providing access to the pharmacopoeia names.
For help with nomenclature I thank Charles Jarvis (Natural History Museum) for checking all the Linnaean names and for helpful advice on nomenclatural problems. For help on particular groups I thank Chris Humphries, Sandy Knapp, Amanda Waterfield, Peter Roberts, Brian Spooner, Beryl Simpson, John Dransfield, Piers Trehane, Toby Pennington, Zofia Lawrence, Lisa Offord, Jennifer Bryant, Mats Wedin, William Purvis, Ian Tittley, David John, Len Ellis, Mary Gibby, Alison Paul, Caroline Whitefoord, Pat Wolseley and Norman Robson.
All names were checked from the Botany and General libraries of The Natural History Museum, The Royal Botanic Gardens, Kew and The Wellcome Institute. I am especially grateful to Judith Magee for locating elusive publications, and to Malcolm Beasley, Carol Gokce, Debbie Gale, Emma-Louise Smith, Andrea Hart, Armando Mendez, Fiona Baker for help with other library matters. Finally, thanks are due to Isabelle Mazille for help with data input and especially to Brian Spooner (Royal Botanic Gardens, Kew), and Pat Wolseley for valuable comments and editing of the final text, and to all those who have given their photographs.