The reception of this book since its original publication some 15 years ago, and the frequent questions put to the author over the past decade about a revised edition, suggest that it has found a place amongst the tools of working botanists as well as of reference librarians. I hope this revision will find a similar reception, in spite of – inevitably – an increase in bulk.

In the nearly 20 years since coverage was closed for the original edition, floras and related works have continued by and large to gush forth. The need for them remains, although it may be driven more by practical than by academic considerations. The renewal and increasing prominence of the environmental and conservation movements, the associated promulgation of international treaties such as the Convention on International Trade in Endangered Species (CITES) and the Convention on Biological Diversity (CBD), and the consequent requirement to have a better understanding of national biotas have moreover created new ‘markets’ for floristic information. This is all in addition to natural cycles of renewal as scientific knowledge expands and deepens, best expressed in more developed countries. Altogether, many more new floras and enumerations have been published than superseded, improving coverage for many parts of the world – sometimes well beyond what was the case in 1979 (Map I). They retain an important place within the botanical literary warrant, and continue to be one of the most important points of contact between user and producer.