The purpose of this book is plant identification in the field. It is not meant for the more difficult taxonomic problems requiring microscopes and herbaria. Therefore my evaluation of the book is based upon the ease of its use in the field. Some features are both positive and negative depending on point of view.Positive features, which enhance speed of keying in the field:
1. Restricted geographic coverage to Michigan for a Michigan botanist.
2. Compact size in a single volume.
3. Reduced species coverage to the most widespread species, excluding single county records. This is helpful in difficult taxa (grasses), but only if you are certain that the species is common enough to be in the book.
4. Family keys go right to species, eliminating need to re-key the same couplets when genera are complex.
Negative features, which may frustrate some users:
1. No seedless vascular plants such as ferns (but Voss ignores these too), the greatest problem.
2. Keys are in "goto" format. I prefer indented nested keys for quicker runs through. A nested key is easier for me to start and stop anywhere without losing my place than a "goto" key.
3. Families are arranged non-alphabetically (using obsolete Engler& Prantl system) requiring the extra step of referring to the index.
4. No mention of whether species are native or introduced. Although not essential for field identification, it is useful information to have this information when learning new species. In more extreme words: should we admire or curse the plant we see before us?
5. Incomplete coverage of difficult taxa leads to uncertainty of identification. Fewer and faster is a poor replacement for correct names.
6. Species come out directly in family key, requiring a longer time keying in cases in which you are already certain of the genus. Sometimes species within a genus are split up into distant portions of the key.
