This book is the second edition of Malesian Seed Plants: Spot Characters, by van Balgooy (Reference van Balgooy1997). The previous edition formed the first part of a trilogy of books, and was followed by Malesian Seed Plants: Portraits of Tree Families (van Balgooy, Reference van Balgooy1998) and Malesian Seed Plants: Portraits of Non-Tree Families (van Balgooy, Reference van Balgooy2001). For much of the past 20 years, this trilogy has been an essential reference for professional and amateur botanists interested in the identification of plants from the Malesian region (Indonesia, Malaysia, Singapore, Brunei, Philippines, Timor-Leste and Papua New Guinea) and beyond. The purpose of the spot characters book is to help identify genera or families of (mainly) angiosperms through distinctive or unusual features of the vegetative or reproductive parts. In the first edition of the book, the author listed 105 spot characters. Each was briefly introduced, in most cases illustrated by a line drawing, and the list of genera, or occasionally families, of occurrence was presented in alphabetical order. As the author admitted in the introduction, some lists were incomplete, and some characters were omitted to accelerate the publication of the book.

This new edition was prepared with the contribution of two additional authors, Y. W. Low and K. M. Wong. The book is remarkably improved in its appearance, with the drawings entirely replaced by colour photographs. The spot characters have been increased to 119 and, as previously, are ordered by category (Stem and Branch Characteristics, Exudates, Smells, Stipule Characters, etc.). This edition features 17 categories, compared with the 13 used in 1997. The additional categories result from the separation of the leaf characters into different headings, and this is a welcome change that simplifies the index search. Each category of spot characters is colour-coded. The individual spot characters are numbered and, as in the first edition, they are described in a short informative paragraph. As mentioned, the illustrations consist entirely of colour photographs, most of them of living plants and only a few of dried herbarium specimens. To make the book still useful within the herbarium environment, the authors have chosen to focus on characters that remain visible in dried specimens. Characters that tend to become lost in the drying process, for example the colour of the various parts of the plant, are included in the book but represent the sort of striking features that collectors might include in their field notes anyway. The list of taxa in which the spot character occurs is now much clearer, with the genera ordered by family. The authors have based their classification on the APG III system, but for new or significantly modified taxa, both the old and the new names are provided.

Malesian Seed Plants: Spot Characters is very easy to use: once a distinctive character of the plant needing identification is searched, the book returns a list of taxa ordered by family. This is it: an immediate shortlist of the angiosperm families and genera with that particular character. To proceed any further with the identification, other references will usually be needed to work at genus and species level. What might appear a weakness is in fact the strength of the book: by avoiding bulky descriptions of taxa and identification keys, the authors have made Malesian Seed Plants: Spot Characters a handy little guide that, in the presence of spot characters, greatly simplifies the often time-consuming process that is plant identification. This shortcut is especially useful in a region of the world, Malesia, still very sparsely covered by floristic treatments.

Among the identification guides published recently, Malesian Seed Plants: Spot Characters certainly stands out for its uniqueness and geographical focus. I would be delighted to see in the next few years second editions of the two other books in the series, and perhaps an electronic version of Spot Characters, with, for instance, the possibility of searching for multiple characters and an extended image gallery.