An illustrated guide to common grasses, sedges and rushes of New Zealand, by Paul Champion, Trevor James, Ian Popay and Kerry Ford

An illustrated guide to common grasses, sedges and rushes of New Zealand, by Paul Champion, Trevor James, Ian Popay and Kerry Ford. Christchurch, New Zealand Plant Protection Society, 2012. 208 pp, NZ$59.99 (paperback). ISBN: 9780473216603

Plant identification guides are evolving rapidly. Recent innovations include interactive keys on line (e.g., http://www.landcareresearch.co.nz/resources/identification/plants) or on tablets or phones (e.g., http://dbiodbs.units.it/carso/chiavi_pub21?sc=308), and in the near future we might be using automated recognition, similar to face recognition algorithms (http://www.i-bo-planet.com/) and DNA barcoding (Hebert et al. 2003). Not all of these work in the field yet, but all have the potential to become portable and automated. They all depend heavily on taxonomic research and Flora-writing, which are also rapidly evolving to make use of new technologies—databases, phylogenetics and geographic information systems.

This field guide to grasses, sedges and rushes is a book in the traditional format, but it incorporates up-to-date taxonomy and nomenclature, the best of plant imaging and reproduction, and some innovative key design. Moreover, it bravely tackles three difficult but important plant groups whose similar growth forms, leaves, tiny wind-pollinated flowers and specialised terminology make their identification a daunting prospect for many. The foreword notes that many lay and professional botanists avoid the grasses, sedges and rushes, believing they all look the same. One aim of the book is to dispel that notion.

In a book like this it is necessary to draw sensible limits to what is included, both taxonomically and ecologically. Here, full treatments are given to both native and naturalised plants that are likely to be encountered in habitats that most users frequent. By my count, full treatments are provided for 32 sedges (NZ total—226 species; Breitwieser et al. 2012), 15 rushes (69 species) and 84 grasses (465 species), but many more species are given a shorter comparative treatment and are often comprehensively illustrated. Thus, I think the book will enable users to identify common grasses, sedges and rushes in New Zealand. Some look-alikes from other families are left out, although most of these are not common enough to warrant inclusion anyway and there is a good discussion of this issue on pages xiv–xv.

The introduction includes an appealing section on differences among the three families. Although the most reliable diagnostic features are found in the microscopic flowers and fruits, some useful vegetative characters are also described, explained and illustrated here.

A listing of common species by habitat is also very helpful and will augment the taxonomic and morphology-based body of the book. Here the experience of the authors is nicely complementary, so that pasture, cropping, urban and wild habitats are all authoritatively covered. The introduction concludes with a useful glossary, augmented by stunningly clear and beautiful digital images. These would be more useful if accompanied by scales.

The body of the book treats the three families. Each major treatment starts with a short statement of the characteristic features of the plants, then a longer description, followed by distribution, habitat notes, comments and derivation of the botanical name. Similar species are then briefly compared in a paragraph each. Outstanding photographs, all in full colour, support both major and minor entries. Headings for introduced species are in magenta type, whereas those of native species are in green.

The sedges (Cyperaceae) are an important family in New Zealand, where native species still outnumber introduced ones. The tabular key to sedge genera summarises their diagnostic characters. The features are cleverly arranged on the page to make it also a graphical presentation of the taxonomic and morphological diversity in the family. The authors have, commendably, replaced many technical terms with plain English; I particularly liked ‘flower head a tight knobbly ball’. For the sedges and the grasses, a tabular key to the species within large genera would have been very helpful. The treatment of rushes (Juncaceae) begins with a similar tabular key, this time to species and species groups. For the grasses (Poaceae), there are too many species and genera to present such a key on a single page, but instead numerous smaller tabular keys are provided, based first on the shape of the heads and second on presence of awns and floret size. This breaks a large family down into manageable groupings. In all three families, the genera are then treated alphabetically rather than grouped by growth form or taxonomic classification, which sometimes separates look-alike plants, except for the bamboos, which are treated together.

I found very few errors and these were minor. I noted Scirpus nodosa (rather than nodosus) as a synonym of Ficinia nodosa, and the statement ‘formerly Scirpus’ after Isolepis would be more accurately expressed as ‘formerly included in Scirpus’. The design is attractive and the production seems robust enough for field use.

This is a book that focuses on usefulness to the user. In particular, the clear explanations and descriptions, the avoidance of technical terminology, the clear and comparable descriptions, the comprehensive introduction, and especially the outstanding, clear and informative illustrations make it an essential reference for farmers, growers, conservationists and botanists in New Zealand. It will not solve all the identification problems with these difficult plants, but it is a powerful addition to the identification toolbox and it contains a wealth of information about the habitats, communities, importance and biodiversity of grasses, sedges and rushes. I strongly recommend it.

P Garnock-Jones

Emeritus Professor

School of Biological Sciences

Victoria University of Wellington

Email: [email protected]

© 2013 Phil Garnock-Jones