This is a remarkable achievement by a remarkable person. David, who was born in New Zealand, has worked tirelessly on New Zealand lichens since his interest was first kindled in 1956, and fittingly was awarded the Acharius Medal of the International Association for Lichenology in July 2008 for his life-time's contribution. From 1972 to 1994 he was based at the Natural History Museum (NHM) in London, until 1982 being seconded from the New Zealand Department of Scientific and Industrial Research (DSIR). The latter recognized that the NHM was the best place to study New Zealand lichens, and he subsequently became a Research Fellow and then Head of the Lichen Section. A list of his 319 scientific publications from 1964–2006 is provided by Arvidsson (Reference Arvidsson2007), amongst which his Flora of New Zealand – Lichens (Galloway Reference Galloway1985) was pre-eminent. That was the first comprehensive account of lichens in any country in the Southern Hemisphere, including all lichen-forming fungi and not only the macrolichens.

However, the 1985 Flora was “primarily a herbarium-based compilation” (Preface p. xiii), but since David's return to New Zealand in 1994 in particular, a vigorous new period of fieldwork has resulted in the discovery of numerous additional species. The 1985 Flora accepted 958 taxa in 210 genera, but the number in the new “revised second edition” has increased to 1706 taxa (of which 388 are endemic) placed in 354 genera – an increase of a staggering 70% in 20 years. I say 20 years as the Preface is dated June 2005 and that is the cut-off year for the account of “Exploration” in volume 1.

Volume 1 starts with the introductory material and keys. The six thallus-type keys of the 1985 Flora are here expanded into 13 keys to genera, plus one to the lichenicolous fungi included. As before, the keys to species within the genera are included in the text. The arrangement of the genera is strictly alphabetical, with Abrothallus to Pachyphiale in volume 1, and Pannaria to Zwackhiomyces in volume 2. The taxonomy is generally up-to-date, including the expanded concept of Xanthoparmelia (i.e. including Chondropsis, Neofuscelia, and Paraparmelia). The first volume includes a signature of 16 top-quality coloured plates which are a testimony to the improvement in colour printing standards since 1985; the last Flora had only eight, of which six were highly pixellated. The second volume has a comprehensive bibliography occupying 181 pages, a short glossary, and a full index which includes synonyms. As in the 1985 Flora, the endpapers at the front show the New Zealand Botanical Region and the Southern Islands, while those at the back have maps of North Island and South Island.

For each species treated, there are full details of the place of publication of accepted names and synonyms, references to published illustrations, a description (but see below), information on the chemistry, an indication of the distribution type, a summary of the distribution and ecology in New Zealand and reports from elsewhere, details of type collections for taxa described from New Zealand, and immensely insightful notes on recognition and other matters.

Yet this is very much a massive supplement to the 1985 Flora rather than a stand-alone work. Not only is the account of Exploration limited to 1985–2005, so that the 1985 work has to be consulted for 1781–1985, but the descriptions of genera and species treated in 1985 are also not repeated here, but are only cross-referenced to the earlier work. However, most importantly, all species are treated in the keys, complete nomenclatural and bibliographical information is retained, later illustrations and descriptions are cited, and distributional data and the all-important cryptic notes on recognition are retained or added. In view of the interdependence of the two editions, inclusion of page references to the 1985 work in the index of the 2007 Flora would have been helpful.

I was especially pleased to see 44 genera of lichenicolous fungi treated, and these and the species names are prefixed by an asterisk to flag them. Embracing lichenicolous fungi is becoming a trend amongst modern “lichen” treatments, both checklists and monographs, and one I encourage as otherwise these fungi receive short-shrift in regional fungal identification aids.

In such a major work, there are always small things that could be picked on or proposed as improvements. I do not propose to mention the inevitable small typographical errors that escaped even David's meticulous eye, though I do note that for “in” in author citations the “,” recommended in the Code since 1999 is consistently omitted, and that where a genus circumscription has been emended, the date of the emendation and not that of the original publication is given (e.g. “Calenia Müll. Arg. emend R. Sant., 1952.” should be “Calenia Müll. Arg., 1890, emend R. Sant., 1952”). I was also disappointed not to see any indication of the families, orders and classes to which the genera are now assigned; a synoptic systematic arrangement on the lines of that in Purvis et al. (Reference Purvis, Coppins, Hawksworth, James and Moore1992) would have occupied only 3–4 pages and would have provided an overview of generic placements. Of more concern to non-specialists using this work for identification is the shortage of illustrations; a reference to figures published elsewhere is little help to those without substantial personal libraries. For the beginner, I would therefore recommend that the superbly illustrated keys of Malcolm & Galloway (Reference Malcolm and Galloway1997) are tried first.

New Zealand lichenology has come a long way since Martin & Child's (Reference Martin and Child1972) 2 cm-thick book covering 300 species. This new book has an overall page size of 21·5 × 15·5 cm, like the first edition, and volumes 1 and 2 are 6·5 and 7·0 cm thick respectively, together weighing 3·7 kg. As the 1985 Flora (which will still be needed) is 4 cm thick, this means the three volumes occupy 17·5 cm of shelf-space. The small size was surely dictated at least in part by the format used for the Flora series. David correctly recognizes (p. xiii) that future editions should be in the Fungi of New Zealand and not the Flora series; it is unfortunate this could not have been done now as the fungal series has a somewhat larger page size (26·7 × 19·1 cm) and would have meant that the volumes were much thinner – as would more use of small type sizes. Purvis et al. (Reference Purvis, Coppins, Hawksworth, James and Moore1992) covers about the same number of species at a thickness of 4 cm, albeit with less nomenclatural and distributional information.

This will not be the last word on the lichens and lichenicolous fungi of New Zealand, and David estimates that 75–80% of species actually present are covered (p. xviii). But just who would discover these taxa and undertake any future revision is unclear, and David highlights the increasing dearth of professional taxonomists. I cannot imagine any employed scientist of today being allowed to focus on such a project for a whole career, especially as the output is in book form and not in high impact-factor journals. David is most fortunate to have had such enlightened managers. In a Foreword to the new volumes, Per Luigi Nimis states that “Any Flora is an ephemeral work” (p. x). I cannot disagree more strongly. Such works are ephemeral only in the sense of not having additional species included and in being subject to changes in taxonomy. They are syntheses of current knowledge, and the foundation of all future work in the areas covered. The Flora of New Zealand – Lichens, the crowning achievement of David's most distinguished career, will be anything but ephemeral, and rather is destined to become a classic work in lichenology to be used by generations to come.