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Gil Nelson, Christopher J. Earle, and Richard Spellenberg. 2014. Trees of Eastern North America. Princeton University Press, Princeton, New Jersey. 720 pp. ISBN 978-0-691-14591-4. Flexibound. $29.95. ISBN 978-0-691- 14590-7. Hardcover. $65.00.

This is an entry in the excellent series of Princeton Field Guides. It covers 825 species in an area whose western boundary is the 100th meridian, which lies slightly to the west of the middle of the Great Plains states of the Dakotas, Ne- braska and Kansas and just cuts off the panhandles of Oklahoma and Texas. Northward, the line runs just east of the western boundary of Manitoba. There is a companion guide to the trees of western North America (not seen) published at the same time and by the same authors, but in a different order (Spellenberg, Earle, and Nelson) that covers 630 species. The coverage includes all species of trees that are native to or naturalized in the area of coverage, as well as promi- nent cultivated street and garden trees. A number of shrubs that are generally taller than a human are also included, though there is no indication as to how complete this representation of “large” shrubs is.

For each species, there is a rather detailed description, a short statement of the habitat and range of the plant, a distribution map (for native species only), and a brief statement describing how the species differs from related species. Some- times this is followed by a paragraph entitled “Note,” which contains additional interesting information about the plant. At the head of each entry is a short para- graph in boldface type, referred to as “Quick ID,” that very briefly gives one or two characters meant to serve as identifying characteristics for the species. Each species entry is accompanied by color paintings by David More. Although the el- ements of the illustrations vary somewhat, most contain an image of a full open- grown tree and details of flowers, fruits, leaves, twigs (including buds), and often a slab of bark. Sometimes a full branch is illustrated to show the arrange- ment of leaves and/or flowers and fruits in relation to each other.

A drawback to this book for serious users is that there are no dichotomous keys. Instead, in the introduction there are eight pages of small paintings of leaves under the heading, “Key to Selected Angiosperm Trees by Leaf Shape.” The first prob- lem is apparent in the word “Selected,” which makes it clear that this “key” is in- complete, and there is no indication of how incomplete it is. So, at the outset, there is no guarantee that the particular tree you are trying to identify is even included in the key. Then one scans the eight pages for particular categories—there are 32 leaves illustrated under the heading, “Simple Leaves, Margins entire, Leaves Op- posite,” 61 under “Simple Leaves, Margins Entire, Leaves Alternate,” and 45 under “Simple Leaves, Margins Toothed, Leaves Alternate,” to mention three cat- egories. There are no further divisions under these broad headings. Nor is there any indication of what the important characters are for any given illustration, whether it is the shape of the apex or the base, the ratio of width to length, the length of the petiole, the vestiture, characters of the venation, the presence or absence of glands, or anything else. Each illustration is accompanied solely by the English name of a

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tree and a page number. It will be obvious at once to anyone at all familiar with the wide variability of individual leaf shapes, even on a single tree, that an attempt to make an accurate identification using this “key” is likely futile. This is preceded by five pages of paintings of “Winter Twigs of Selected Eastern Trees,” again divided into various broad categories. The 167 species so illustrated constitute a mere 20% of the 825 species included in this field guide.

Considered in isolation, this is unquestionably an excellent field guide—it of- fers complete coverage, excellent illustrations, distribution maps, and aids to identification. But there are many other guides to trees that cover all, or a por- tion, of the same area, and one must ask whether this book offers anything that others do not, or whether what it does offer is better than what other field guides offer. In my view, the answer to both questions is “No.”

For serious use in the field, it is generally preferable to use a guide that is more localized, covering, for example a single state or similar region. It is much easier to identify an unknown oak from among the 12 species included in Barnes and Wagner’s Michigan Trees (revised and updated edition), the 20 included in Native Trees of the Midwest (second edition), by Weeks et al., or the 21 included in Trees of Missouri, by Don Kurz, than from among the 45 species included in this field guide. In addition to a more localized coverage, each of these guides contains useful aids to identification that are lacking in Trees of Northern Amer- ica. Three of them have full dichotomous keys, to families, to genera within fam- ilies, and to species within genera, often including separate keys to summer and winter material. The Michigan and Missouri guides contain superb line drawings for each species, including separate drawings of leaves, buds, flowers, fruits, winter twigs, and more, and occupying an entire page for the illustration of a sin- gle species. The Midwest guide has detailed close-up photos of the same fea- tures, again with a single species to a page. All have detailed descriptions, and the Missouri guide puts those parts of the descriptions that are particularly valu- able for identification in boldface.

A particularly useful comparison is with Thomas Elias’s The Complete Trees of North America. This is almost exactly the same size and thickness as Trees of Eastern North America, but, like the more focused guides already discussed, has many identification features that are lacking in the newer guide—full dichoto- mous keys, arrows on the drawing pointing out important characteristics, and boldface to emphasize those passages in the detailed descriptions that are partic- ularly useful for identification.

One wonders what audience this book is intended for. There is no indication ei- ther in the introductory material or on the cover, save for the statement at the end of the front jacket flap that “this is an essential guide for every tree lover.” For the beginner, there are other guides that are more usefully localized and permit more accurate identifications; for the expert, it is too lacking in the standard methods of identification, not to mention any synonymy, to make it useful for field use. It is comprehensive and up-to-date. The descriptions are thorough, and the illustrations are excellent. It can profitably be used in conjunction with other guides, and will serve as a useful shelf reference. I will undoubtedly consult it from time to time. But it cannot be recommended as a first choice for field identification.

——Michael Huft

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Stewart McPherson and Donald Schnell. 2012. Field Guide to the Carnivo- rous Plants of the United States and Canada. Redfern Natural History Pro- ductions Ltd., Poole, Dorset, England. 200 pp. ISBN 978-1-908787-08-8. Soft cover. £12.99. Available from:

This welcome field guide to the carnivorous plants occurring in North America is a handy book that can easily be carried out in the field. Perhaps the thing that strikes one first is the stunningly beautiful photographs, some of which are pre- sented as full-page images, without borders. The field guide is profusely illus- trated with 300 images, (most of them provided by Stewart McPherson and Barry Rice, but some contributed by 36 other photographers, and covers four families (Bromeliaceae, Droseraceae, Lentibulariaceae, Sarraceniaceae), eight native genera (Catopsis, Dionaea, Drosera, Pinguicula, Utricularia, Darlingto- nia, Sarracenia), and 47 species. Numerous infraspecific taxa are also included, chiefly varieties and color forms within the genus Sarracenia—perhaps as a con- sequence of the authors having just published a new book on the Sarraceniaceae (McPherson and Schnell 2011). Also included in this field guide is an Old World aquatic plant of the Droseraceae, Aldrovanda vesiculosa (waterwheel plant), ap- parently recently introduced locally in New York, New Jersey, and Virginia.

The book is organized alphabetically, first by family—giving brief com- ments—then by genus, with brief generic information, a section on plant struc- ture for the genus, a generalized diagram representing the genus, and comments on habitat and ecology. Species are then alphabetically arranged, giving scien- tific name and author, common name, literature for the original description (al- though none cited for taxa transferred to another genus or changed to another taxonomic level), and derivation of specific epithet, along with general geo- graphical distribution (no maps), habitat, descriptive features (vegetative and floral), and occasionally taxonomic comments. Toward the end there is a section enumerating natural hybrids of North American carnivorous plants. The book concludes with a brief discussion addressing issues of conservation of North American carnivorous plants. I only wish that the book included some kind of key to help distinguish those taxa that are rather similar—although the text does address potential problems of misidentification of certain “look-alikes” and “species pairs.” There is no table of contents, and no index.

Although a wealth of information is presented in this handy “field-friendly” book, I was surprised to find a bibliography of only two references. Perhaps this is because the authors feel that their other published works more fully cite litera- ture sources. For instance, Schnell’s Carnivorous Plants of the United States and Canada, 2nd edition (Schnell 2002) provides an extensive bibliography citing his sources. And I was also surprised that none of the 300 images is attributed to Donald Schnell. Was this to avoid duplication of information he presented in his second edition? Should that be the case, I believe it appropriate to emphasize that this new field guide does not replace Schnell’s classic reference on our native car- nivorous plants, which is full of very valuable information on the biology of these fascinating plants as well as on their taxonomy, and which is well-illustrated with many excellent photos and diagrams.

As one would expect with any work dealing with taxonomic diversity, not all

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botanists will be in agreement as to the taxonomy adopted. For instance, in my taxonomic treatment of Lentibulariaceae for Flora of North America North of Mexico (Crow, in press), I treat Utricularia macrorhiza as a subspecies within Utricularia vulgaris (as U. vulgaris subsp. macrorhiza (Laconte ex Torrey) R. T. Clausen). I made this decision after careful comparison of specimens of the Eu- ropean U. vulgaris subsp. vulgaris with North American specimens; given the variation exhibited in these plants and the very minor differences between the two taxa, I felt it best to treat these as a single species. Furthermore, after a re- examination of my own specimens collected from western Siberia demonstrated that those specimens also belong to subsp. macrorhiza, I came to the realization that subsp. macrorhiza is the taxon with the greater geographical range (North America and eastern Asia westward to western Siberia). Similarly, I regard what is treated in the Field Guide as Pinguicula macroceras as conspecific with P. vulgaris—the differences being extremely minor—yet I retain subspecific rank for the usually larger-flowered subsp. macroceras, because the geographic ranges are largely allopatric; yet occasionally specimens occur that cannot be readily assigned to either taxon.


Crow, G. E. In press. Lentibulariaceae [Pinguicula, Utricularia]. In Flora of North America, volume

18. Flora of North America Editorial Committee. Editors. Oxford University Press. New York. Provisional Treatment available at 20provisional.pdf. McPherson, S. and D. E. Schnell. (2011). Sarraceniaceae of North America. Redfern Natural History Productions Ltd., Poole, Dorset, England. Schnell, D. E. (2002). Carnivorous plants of the United States and Canada. 2nd edition. Timber Press, Portland, Oregon. ——Garrett E. Crow Michigan State University Herbarium East Lansing, Michigan, USA