The Lichens of Great Britain and Ireland is an outstanding achievement. It represents the culmination of extensive collaboration stretching over more than seven years among professional lichenologists, including authorities from the British Isles and overseas, with participation also from the wider membership of the British Lichen Society (BLS). When, in 1992, The Lichen Flora of Great Britain and Ireland edited by Purvis et al. appeared, the first comprehensive account of the lichens of the British Isles for over 70 years, it was hailed as a milestone in British and international lichenology, a supreme achievement of modern British lichenology. (The Introduction to British Lichens by Duncan and James from its publication in 1970 had been used as a standard guide; but it covered only 65 per cent of the British lichens.) Now, just 17 years after the 1992 Flora to have a new, much enlarged and enhanced volume, The Lichens of Great Britain and Ireland, is no less a remarkable feat.
Published in 2009 by the British Lichen Society, The Lichens of Great Britain and Ireland weighs in at over two kilograms, its 1056 pages strongly bound within hard-back laminated covers. The inclusion of many new lichen species, increased from 1487 (1992) to 1873 (2009), and genera, increased from 255 (1992) to 327 (2009), has been largely responsible for the almost 50 per cent increase in the number of pages. This much enlarged tome provides complete coverage of lichen species (plus many lichenicolous fungi) and a fresh evaluation of information that lichenologists both here and world-wide have eagerly awaited.
As early as 2001, the BLS recognized that the 1992 Flora was becoming out-dated and a revision was desirable. Oliver Gilbert, to whom this volume is dedicated, had been invited by Anthony Fletcher, as BLS President, to convene a meeting of members and see if they wanted a new volume; unanimous agreement followed. Oliver asked Clifford Smith to help him draft the new book. Oliver and Clifford then invited potential contributors and set up a framework for circulating drafts. The momentum of revision continued, notwithstanding Oliver's untimely death in 2005. Following this, meetings of the ‘Flora Committee’ and editorial team were brought together by Anthony Fletcher. Each member of the editorial team has made a singular and special contribution and together they represent an immense pool of knowledge and expertise.
Overall co-ordination and editorship of this new volume have been successfully provided by Clifford Smith. Contributors' accounts, descriptions and keys were overseen and collated by the team; during 2005–2007 Clifford Smith, Peter James, Pat Wolseley and Anthony Fletcher received and commented on all drafts. Specialist overseas lichenologists were consulted throughout. In 2008 André Aptroot and Brian Coppins oversaw revised drafts which were again reviewed by the full editorial team. Pat Wolseley liaised effectively from the Natural History Museum with the wider BLS membership and specialists in difficult genera. She, with Peter James and Anthony Fletcher, checked the complete typescript and later proof-read the pre-publication copy with Ishpi Blatchley, whose earlier proof-reading had assisted in standardizing the use of terms and punctuation. Information on lichen distribution from the BLS's Distribution Maps Scheme, managed by Mark Seaward, has provided the basis for many of the valuable comments on distribution given by contributors. Additional checking of text and thorough testing of the many excellent keys have ensured the usefulness of this new comprehensive account to a wide range of readers. These have been carried out by numerous BLS members, both individually, as by Ivan Pedley, and on field meetings. In the year preceding publication the current BLS President, Peter Lambley, effectively managed practical matters relating to publication. This mammoth collaborative effort has resulted in an inspirational book of exceptional usefulness and scholarship, the new standard work for identification of lichens in Great Britain and Ireland.
How does The Lichens of Great Britain and Ireland fulfil its own stated aim as ‘a practical guide for the identification of lichens’ (Introduction, p. 2)? The 1992 volume has become, for most of us, heavily used, worn and annotated: it has served us well as a trusted friend. After the passage of time, application of new techniques, acceptance of new names and many taxonomic changes, how does the 2009 revision improve on the 1992 Flora? Does it retain the scholarship and authority of its predecessor? What significant improvements and distinctions does one discover in using it?
The incorporation of additional genera and species, an impetus and of uppermost priority for this revision, necessitated a few compromises to contain the pages within a single binding. Font size and print clarity are somewhat reduced in comparison with those of the 1992 Flora, but the font used in generic descriptions retains more definition, and one soon adjusts to the rest, when it is viewed in good light.
The Introduction fulfils its purpose admirably. It has been increased from 10 to 15 pages with the information in its various sections having been reassessed and rewritten. The paragraphs on substrata and ecology are much enhanced, giving a useful overview. Advice on identification procedure and technique is sufficiently full to be truly practical, although illustrations are not incorporated in context. Any user, progressing from the 1992 Flora to this new volume, who overlooks the Introduction, misses out on well-chosen information and a very good read.
Preceding the Introduction, a List of Figures is helpfully provided, but without page numbers which would have been useful, especially as no page reference is given when a figure is cited in a generic or species' description. Following this list, the sole table, Table 1 (Verrucaria species) is noted. This table presents information on ascospore dimensions clearly and concisely (including standard deviation), though the accidental omission of its second page limits its use. Inclusion of other comparative tables, either for species within genera or between closely related genera, could have merited serious consideration, as for those many species at one time included in the genus ‘Parmelia’.
Alan Orange's excellent line drawings, many in the Glossary, are sensibly retained from the 1992 volume augmented by drawings of Atla and some additional figures by Anthony Fletcher and Pat Wolseley. More figures would be welcomed, especially for non-specialists. Colour photographs, provided by the late Jeremy Gray, enhance the covers. In this way, they are accorded special significance, but in contrast the body of the book appears visually dense in text and unrelieved. Provision of illustrations, for even a small fraction of the species described, would have been a mammoth undertaking and impractical – certainly impossible in a single volume. However, a small number of high quality colour photographs, perhaps of characteristic lichen communities, strategically placed within the text, could have been included for visual and aesthetic impact. While in this volume the illustration of species is sparse, the editors are to be commended for providing a very useful alternative that is a marked improvement over the 1992 edition. Reference is made at the end of each species' description to one or more sources of illustration, and these are wide-ranging, including Brodo et al. (Reference Brodo, Duran-Sharnoff and Sharnoff2001) and van Herk & Aptroot (Reference van Herk and Aptroot2004). Both of these volumes, excellent in their separate ways, are outstanding for their photographs and also include common names for lichens. But their aims were different from The Lichens of Great Britain and Ireland: they have been more selective. Dobson (Reference Dobson2005), the illustrated guide to 850 lichen species in Great Britain and Ireland, is a useful and frequently quoted reference for species' illustration. Additionally, in the Introduction, p.6, in the sub-section ‘Illustrations’, website galleries are recommended; these, and also illustrated on-line keys, are increasing in importance.
An overview of the systematic arrangement of the genera comes after the Introduction. This is a useful inclusion because, as in the 1992 Flora, organisation is alphabetical throughout this volume for genera (and for most species within genera). A summary figure showing the phylogenetic relationships of lichen groups in the Ascomycota, concludes this section.
The Glossary has been placed at the front of the volume, rather than at the end, as in 1992. While this may not be customary, it fits well and gives greater definition to the sections References and the carefully presented taxonomic Index at the end of the book.
The prime aim of The Lichens of Great Britain and Ireland is provision of accurate and helpful guidance on the identification of genera and species, in a form accessible to a wide variety of users (but it is not a beginners' book). In this, the book is hugely successful. Keys are an outstanding strength, led by the phenomenal sequence headed Generic Keys (83 pages, enlarged from 43 pages in 1992). This includes additional genera and sterile saxicolous lichens, which were not included in 1992. The rigour in the construction of the Generic Keys, a team effort by the editors, ensures both precision and flexibility, with alternative pathways incorporated for some genera and/or species. While entities can be successfully keyed out, the omission of page references to the constituent sections of the Generic Keys (eight main keys, subdivided into 24 in all) both in the Contents and at the start of Generic Keys, renders their use awkward, in comparison with the 1992 version. This omission assumes importance because of the large number of pages and items encompassed and is significant, working in hard-copy.
Generic and species descriptions, the main substance of the book, are enjoyable to read and provide clear detail and precise help with identification. The editors have collated the contributions of individual authors, standardizing and imparting overall consistency to the volume. Thus the user is secure in relying on the organisation of material, which is very helpful and satisfying. At the same time, many of the descriptions reveal the stamp of individuality, reflecting the style of contributors and distinctive features of the genera and species concerned. These qualities cultivate the interest of the reader.
At the start of each generic section, the name of the contributor is helpfully provided. In most cases, where the revision of the 1992 account has been straightforward, the first-named contributor made the current revision, while the secondary contributors had been responsible for the 1992 account. In many places, however, the revision is so considerable that it often constitutes a new account. Separate listing of genera with contributors' names, as in the 1992 Flora, has been omitted. The descriptions of general characteristics given for each genus (e.g. photobiont, ascomata, ecology, distribution) are intended to be used alongside the descriptions of species, which follow in the text. A special strength of these generic descriptions is the inclusion of comparative discussion of related genera and/or difficulties in defining the taxa within the genus. Where further study is required (e.g. molecular work in Lecania), this is noted. Such reference enables the user to feel more of a participant: species within a genus are not ‘set in stone’ but part of a stimulating on-going process in which the observations of the individual user gather weight. However, the present volume has not embraced prematurely and indiscriminately every new bit of evidence on speciation (especially molecular evidence) but has adopted a conservative viewpoint with an eye on the future (e.g. see Verrucaria). Generic descriptions are closed with reference to lichenicolous fungi and citing of relevant literature.
In keys for the identification of species, emphasis has been placed on field characteristics, morphology and microscopic features (see Bacidia) and simple chemical spot tests, making the keys accessible to the non-specialist. Reference is made to recent molecular and chemical work, without requiring keys to rely solely upon this information. Supporting this approach, alternative and supplementary keys are provided as, for example, in Lepraria, where the main key relies on thin layer chromatography, but an alternative one relies on more traditional morphology and spot tests. In Verrucaria, supplementary keys are based on freshwater and marine/maritime habitats. Some large, complex genera like Caloplaca and Lecanora have a useful synoptic key preceding the main key to species. (In a few cases closely related genera, e.g. Trapelia and Trapeliopsis, are incorporated into a single key.)
Descriptions of individual species, arranged alphabetically, follow the dichotomous keys to the species within each genus. Unlike in the 1992 Flora, species are not numbered in their alphabetical sequence but each is provided with its BLS mapping number which gives it relevance and significance for the mapping scheme and cards used in surveys. Synonyms are provided only for taxa renamed since the 1992 Flora. (A comprehensive list of synonyms is available on the BLS website, www.thebls.org.uk, and is updated twice yearly.) Species descriptions, which give weight to diagnostic and distinctive features, are followed by information on chemistry (including spot tests), habitat and distribution. While the detail of distribution is almost always remarkably accurate, an occasional curious anomaly occurs. Useful notes, giving advice on variations and comparisons for species which are closely similar, provide invaluable focus. The description is concluded by citing sources of illustration for the species.
In The Lichens of Great Britain and Ireland we have gained an unrivalled and invaluable account of our lichen-forming fungi. While, admittedly, most of us might not choose to carry a book of this size and weight into the field, it can travel in the car or suitcase and will always be a reliable and constant companion on the workbench. This new scholarly publication of the BLS is justified by the pace of change and increase in information. Without it, many lichenologists could flounder in keeping abreast of taxonomic developments and nomenclature changes. Considering its very reasonable price, this volume is likely to require a reprint in the near future. Then, apart from addressing insignificant typographical errors, inevitable in such a lengthy tome, there would be opportunity to correct small inconsistencies in descriptions and keys (e.g. see Heterodermia). Suggestions regarding page-number references and inclusion of more illustration and tables, carefully selected, might also be considered, as well as the scope of on-line accessibility. These could make it even better and more useful and attractive to a wider range of lichenologists.
We owe heartfelt gratitude to all involved in the preparation of this volume: an achievement of which BLS members can feel justly proud. Its value, as the new standard work, is immense in its comprehensiveness, scholarship and general readability. The Lichens of Great Britain and Ireland successfully achieves the aim of guiding the identification of lichens for specialist and intermediate-stage lichenologists alike. It greatly strengthens lichenology by building on much progress and new understanding of taxonomic concepts, and points to ways to further developments in our knowledge.
