The geographic scope of the work extends from the Canadian border south through Long Island and west to the Hudson River. The "General Keys" section contains fourteen keys that include such groups as aquatic plants, vines, and woody plants in winter condition. For both woody and herbaceous families, the keys cover flowering as well as fruiting condition.

The "Descriptive Flora" section includes keys to all of the genera and species, descriptions of the families and genera, and accounts of the individual species. The latter incorporate information on wetland site index, rare status, wildlife food value, food and medicinal value for humans, and poisonous or hallucinogenic properties.

The distributions of more than 2,400 species are presented on range maps, and the book includes line drawings of 995 species, showing diagnostic features designed to clarify descriptions used in the keys. Near the end of the volume there are two matrices of diagnostic characteristics, one for dicots and one for woody plants in winter condition. These matrices can be used to identify a specimen displaying limited information, or to find examples of given vegetative, flower, or fruit characteristics for use in teaching.

Throughout the book, the keys have been made as user-friendly as possible, employing in most cases short, concise couplets rather than long, cumbersome ones. Presenting a wealth of scientificallyaccurate information in a precise and clear format, this volume will be extremely useful as as a reference work, as a textbook for courses in plant systematics, and as a field manual.