The Present work is the first complete Illustrated Flora published in this country. Its aim is to illustrate and describe every species, from the Ferns upward, recognized as distinct by botanists and growing wild within the area adopted, and to complete the work within such moderate limits of size and cost as shall make it accessible to the public generally, so that it may serve as an independent handbook of our Northern Flora and as a work of general reference, or as an adjunct and supplement to the manuals of systematic botany in current use.

The first edition (6000 copies) was exhausted during the period from 1896 to 1909. The continued public demand for the work has induced the authors to prepare and publish a second edition, which has been materially revised and enlarged. About 300 pages have been added to the text and the number of species illustrated has been increased from 4162 to 4666, besides many others redrawn for improvement. This increase of about one-eighth both in the text and in the number of plants figured is due in part to the more complete botanical exploration of the geographical area, in part to the more critical delimitation of species and in part to the introduction, in recent years, of additional alien species from the Old World and from the western and southern United States. Exploration and critical study have been greatly stimulated by the first edition, and much of the additional information now brought into the second edition was elicited by the use of the first, by students all over the country.

To all botanical students, a complete illustrated manual is of the greatest service; always useful, often indispensable. The doubts and difficulties that are apt to attend the best written descriptions will often be instantly solved by figures addressed to the eye. The greatest stimulus, moreover, to observation and study, is a clear and intelligible guide; and among the aids to botanical enquiry, a complete illustrated handbook is one of the chief. Thousands of the lovers of plants, on the other hand, who are not botanists and are not familiar with botanical terms or the methods of botanical analysis, will find in the illustrations of a complete work the readiest means of comparison and identification of the plants that .grow around them; and through the accompanying descriptions they will at the same time acquire a familiarity with botanical language. By these facilities, not only is the study of our native plants stimulated and widened among all classes, but the enjoyment, the knowledge and the scientific progress derivable from these studies are proportionately increased.

Though most European countries have complete illustrations of the flora of their own territory, no similar work has hitherto been attempted here. Our illustrated works, some of them of great value, have been either sumptuous and costly monographs, accessible to comparatively few, or confined to special groups of plants, or have been works of a minor and miscellaneous character, embracing at most but a few hundred selected species, and from incompleteness, therefore, unsuited for general reference. Scarcely one-third of the species illustrated in the present work have ever been figured before. That no such general work has been previously attempted is to be ascribed partly, perhaps, to the imperfect exploration of our territory, and the insufficiency of the collections to enable such a work to be made approximately complete; partly to the great number of species required to be figured and the consequent difficulty and cost of the undertaking, and partly to the lack of any apparent demand for such a work sufficient to warrant the expense of the enterprise.

In the first edition, it was shown that many more species existed within the geographical area of the work than previous publications had recorded, and many collectors and students have, since its publication, been eager to detect and describe others. This enthusiasm for additional species had led, in some instances, to the descriptive publication as species, of a considerable number which appear to be not sufficiently different from plants already well known to warrant their recognition as distinct; some of these have been satisfactorily relegated to synonymy, while others have been recognized in this edition by brief notes in order to call attention to them and to indicate the necessity for their further study, in order to ascertain their true status. Similar notes have been entered relative to a few species of which the occurrence within the area has become known to the authors during the preparation and composition of the work, which has covered a period of nearly four years, a course which has been taken in order to supersede the need of an Appendix.

A few species illustrated in the first edition have been omitted, except by the entry of notes upon them, in the second, for reasons explained by such notes, mostly because they have been ascertained to be undistinguishable specifically from others.

The enterprise, projected by Judge Brown, and maintained and supervised by him throughout, has been prosecuted for the past twenty-two years. Its execution has been mainly the work of Dr. Britton. The text, founded upon a careful examination of living or herbarium specimens, has been chiefly prepared by him, with the assistance, however, of specialists in a few groups who have contributed the descriptions for certain families as stated in the footnotes. The figures also have been drawn by artists under his immediate supervision; except those of most of the grasses, drawn for the first edition by Mr. Holm, under the eye of Prof. Scribner, and those in the other families contributed by specialists who have supervised them; while the work in all its parts has been carefully revised by both authors. The keys to the genera and species, based upon a few distinctice characters, will, it is believed, greatly facilitate the determinations.

In preparing a new work of this character, the authors have felt that there should be no hesitation in adopting the matured results of recent botanical studies here and in Europe, so as to bring the work fully abreast of the knowledge and scientific conceptions of the time, and make it answer present needs. Although this involves changes in systematic order, in nomenclature, and in the division of families and genera, such as may seem to some to be too radical, no doubt is entertained that time will fully justify these changes in the judgment of all, and demonstrate that the permanent advantages to Botanical Science will far outweigh any temporary inconveniences, as has been already so fully shown in Ornithology and other zoological sciences.

The first edition was issued in three volumes, published consecutively in 1896, 1897 and 1898. The second edition is issued in three volumes simultaneously published.