An Illustrated Flora of the Northern United States, Canada and the British Possessions/Introduction


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.

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 will the study of our native plants be stimulated and widened among all classes, but the enjoyment, the knowledge and the scientific progress derivable from these studies will he 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-quarter 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.

The increased accumulations of material in our largest herbaria, the result of multiplied explorations, and the widely extended interest in the study of our native plants, seem now to justify the endeavor to supply a complete illustrated work adapted to general use.

The enterprise, projected by Judge Brown, and maintained and supervised by him throughout, has been diligently prosecuted for the past six 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 by Mr. Holm, under the eye of Prof. Scribner; 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 distinctive 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 the botanical studies of the last half century 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 work will be completed in three volumes and will be issued as rapidly as it can be printed, the text being already written and the figures drawn.



The area of the work extends from the Atlantic Ocean westward in general, to the 102d Meridian, a little beyond that of Gray's Manual, so as to include the whole of the State of Kansas; and northward from the parallel of the southern boundary of Virginia and Kentucky to the northern limits of Labrador and Manitoba.   For convenience, the whole of Nebraska has been included, thus permitting the illustration of practically the entire Flora of the northern portion of the Great Plains.  Western North and South Dakota are not included.

The Flora of Canada and the British possessions not being distinguishable by any well marked features from that of the adjacent parts of the United States, and not embracing more than about 300 additional species, it was deemed best to include this more northern territory, in order to present a manual of the whole Flora of the northeastern part of the continent, with the exception of that of Greenland and the Arctic Circle, which is much the same on both continents; nearly all the Arctic plants are, however, included, as but very few of them are strictly confined to the Arctic Zone.

Further botanical exploration will, doubtless, reveal additional species, especially along the southern and western boundaries, and in the north.



Within the above area there are over 4,600 recognized species, more than three times the number in Bentham's Illustrated Handbook of the British Flora.   To illustrate all these in a work of moderate size and cost, only parts of each plant could usually be figured, and these mostly below life-size.  To exhibit full-page illustrations would have added fourfold to the bulk of the work, and the consequent more limited sales would have necessarily increased the price in a much greater proportion, and thus have thwarted the primary object, viz., to supply a work adapted to general circulation and use.  On the other hand, it was found that any considerable further reduction of the figures in order to reduce the size of the work, would be at the sacrifice of the clearness and usefulness of the illustrations.

In the general plan adopted and in giving parts only of the larger plants, it has been the constant aim to make the reduction of each figure as little below life-size as possible, to select the most characteristic parts for illustration and to preserve the natural proportions. In these respects, it is believed, the present work will be found to be at least not inferior to that above named and often superior.

The cuts are all from original drawings for this work, either from life or from herbarium specimens, though reference has constantly been made to published plates and figures.   All have been first drawn life-size from medium-sized specimens, and afterwards reduced to the proportion indicated by the fraction near the bottom of each cut, most of them being from 1/2 to 2/3 of medium life-size.  By this method the illustrations do not suffer from the use of a magnifier, but are improved by it and regain their full expression.

The large number of additional figures in the second edition and the incorporation into the main text of the appendix to the first edition, have necessitated the renumbering of the figures consecutively.

Enlargements of special parts are added in most of the illustrations in order to show more clearly the floral structure, or minute organs, or the smaller flowers. These are in various degrees of enlargement, not deemed necessary to be stated.   The figures are uncolored, because coloring, except in costly work, obscures the fineness of linear definition and injures the cuts for descriptive and educational uses.


The Classification of Plants.

The Plant Kingdom is composed of four subkingdoms, or primary groups:

1.   Thallophyta, the Algae, Fungi and Lichens.

2.   Bryophyta, the Mosses and Moss-allies.

3.   Pteridophyta, the Ferns and Fern-allies.

4.   Spermatophyta, the Seed-hearing plants.

Individuals are grouped, by similarity, into races; races into species; species into genera; genera into families; families into orders; orders into classes; classes into divisions or subkingdoms.

In addition to these main ranks, subordinate ones are sometimes employed, when closer grouping is desirable: thus a Class may be separated into Subclasses, as the Class Angiospermae into the Sublasses Monocotyledones and Dicotyledones; Families may be separated into Tribes, as in the treatment of Gramineae in the following pages; Genera are often separated into Subgenera; Species into Subspecies.

Critical field observations of plants in the wild state, supplemented by the cultivation side by side of species supposed to be distinct and by the lessons learned from experimental plant breeding, have developed the theory that many species, perhaps all, are composed of a greater or lesser number of races, differing from each other too little to cause them to be regarded as species, notwithstanding the fact that they may breed true from seed to such slight or trivial differentiations.   It also seems to have been proved, by DeVries and others, that such differentiations may originate abruptly from seed, in a single generation, and remain constant for at least several generations thereafter if so isolated from their relatives as to prevent cross-pollination.  These recently ascertained phenomena of mutation are most suggestive, and experimentation and observation concerning them are now occupying the attention of many students.

In the present edition of Illustrated Flora, the view is taken that the races composing many species are often too numerous and too slightly characterized to be described so as to be recognized; many of them have been described as species and many more as varieties, and varieties of different degrees of differentation have been suggested. We here regard species alone as entitled to distinct botanical appelation; it has been suggested that races may be indicated numerically.

Other than the omission of descriptions of varieties, the general system of classification used in the first edition has been maintained in the second.   A few new family groups and a number of genera have been separated or distinguished from their congeners.

The grouping of Races into Species, of Species into Genera, and of Genera into Families, though based upon natural characters and relationships, is not governed by any definite rule that can be drawn from nature for determining just what characters shall be sufficient to constitute a Species, a Genus or a Family.   These groups are, therefore, necessarily more or less arbitrary and depend upon the judgment of scientific experts, in which natural characters and affinities, as the most important and fundamental factors, do not necessarily exclude considerations of scientific convenience.  The practice among the most approved authors has accordingly been various. Some have made the number of genera and families as few as possible. This results in associating under one name species or genera that present marked differences among themselves.  The present tendency of expert opinion is to separate more freely into convenient natural groups, according to similarity of structure, habit, form or appearance. While this somewhat increases the number of these divisions, it has the distinct advantage of decreasing the size of the groups, and thus materially facilitates their study. This view has been taken in the present work, following in most instances, but not in all, the arrangement adopted by Engler and Prantl in their great work, Natiirliche Pflanzenfamilien, in which nearly all known genera are described.


Systematic Arrangement.

The Nineteenth Century closed with the almost unanimous scientific judgment that the order of nature is an order of evolution and development from the more simple to the more complex.   In no department of Natural Science is this progressive development more marked or more demonstrable than in the vegetable life of the globe.  Systematic Arrangement should logically follow the natural order; and by this method also, as now generally recognized, the best results of study and arrangement are obtained. The sequence of Families adopted 50 or 75 years ago has become incongruous with our present knowledge; and it has for some time past been gradually superseded by truer scientific arrangements in the later works of European authors.2

It now seems probable that continued investigation and consideration will again modify the sequence of various groups. Many suggestions in this regard have already appeared in botanical literature; notably, in our own country, those of Professor Charles E. Bessey.

The more simple forms are, in general, distinguished from the more complex,

1.   by fewer organs or parts;
2.   by the less perfect adaptation of the organs to the purposes they subserve;
3.   by the relative degree of development of the more important organs;
4.   by the lesser degree of differentiation of the plant-body or of its organs;
5.   by considerations of antiquity, as indicated by the geological record;

6.   by a consideration of the phenomena of embryogeny.

Thus, the Pteridophyta, which do not produce seeds and which appeared on the earth in Silurian time, are simpler than the Spermatophyta; the Gymnospemlae in which the ovules are borne on the face of a scale, and which are known from the Devonian period onward, are simpler than the Angiospermae, whose ovules are borne in a closed cavity, and which are unknown before the Jurassic.

In the Angiospermae the simpler types are those whose floral structure is nearest the structure of the branch or stem from which the flower has been metamorphosed, that is to say, in which the parts of the flower (modified leaves) are more nearly separate or distinct from each other, the leaves of any stem or branch being normally separated, while those are the most complex whose floral parts are most united.   These principles are applied to the arrangement of the Subclasses Monocotyledones and Dicotyledones independently, the Monocotyledones being the simpler, as shown by the less degree of differentiation of their tissues, though their floral structure is not so very different nor their antiquity much greater, so far as present information goes.  For these reasons it is considered that Typhaceae, Sparganiaceae and Naiadaceae are the simplest of the Monocotyledones, and Orchidaceae the most complex; Saururaceae the simplest family of Dicotyledones, and Compositae the most complex.

Inasmuch as evolution has not always been progressive, but some groups, on the contrary, have clearly been developed by degradation from more highly organized ones, and other groups have been produced by divergence along more than one line from the parent stock, no linear consecutive sequence can, at all points, truly represent the actual lines of descent.


Engler und Prantl, Natürliche Pflanzenfamilien;
Warming, Systematic Botany, 1895;
Vines, Student's Handbook of Botany, 1895;
Richter, Plantae Europeae, 1890;
Thomé, Flora von Deutschland, OEsterreich und der Schweiz, 1886-1889;
Potoniė, Illustrirte Flora von Nord und Mittel-Deutschland, 1887;
Schlechtendahl, Langethalund Schenck, Flora von Deutschlan, fifth edition by Hallier, 1880-1885.



The names of genera and species used in this work are in accordance with the Code of Nomenclature recommended by the Nomenclature Commission of the Botanical Club of the American Association for the Advancement of Science, published in Bulletin of the Torrey Botanical Club 34: 167-178, 1907, to which reference is made.   The synonyms given under each species in this work include the recent current names, and thus avoid any difficulty in identification.

The necessity for these rules of nomenclature arose from the great confusion that has existed through the many different botanical names for the same species or genera. Some species have had from 10 to 20 different names, and, worse still, different plants have often had the same name. For about 200,000 known species of plants there are not fewer than 700,000 recorded names. Such a chaotic condition of nomenclature is not only extremely unscientific, burdensome and confusing in itself, but the difficulty and uncertainty of identification which it causes in the comparative study of plants must make it, so long as it continues, a serious and constant obstruction in the path of botanical inquiry.

The need of reform, and of finding some simple and fixed system of stable nomenclature, has long been recognized. This was clearly stated in 1813 by A. P. De Candolle in his Theorie Elementaire de la Botanique (pp. 228-250), where he declares priority to be the fundamental law of nomenclature. Most systematists have acknowledged the validity of this rule. Dr. Asa Gray, in his Structural Botany, says (p. 348):

"For each plant or group there can be only one valid name, and that always the most ancient, if it is tenable; consequently no new name should be given to an old plant or group, except for necessity."

This principle was applied to Zoology in the Stricklandian Code, adopted in 1842 as Rules of the British Association, and revised in 1860 and 1865 by a committee embracing the most eminent English authorities, such as Darwin, Henslow, Wallace, Clayton, Balfour, Huxley, Bentham and Hooker. In American Zoology the same difficulties were met and satisfactorily overcome by a rigid system of rules analogous to those here followed and now generally accepted by zoologists and palaeontologists.

At an International Botanical Congress held at Paris in 1867, in which unfortunately the English botanists did not participate, A. DeCandolle presented a system of rules which, with modifications, were adopted, and, as above stated, are the foundation of the present rules of the botanists of the American Association. These rules were in part adopted also by the International Botanical Congress held at Genoa in 1892, and by the Austro-German botanists at their meeting in September, 1894; while in the 9th Edition of the London Catalogue of British Plants published in 1895, these rules as respects the names of genera are largely followed; out of 4-l0 genera in common with ours, all but 18 bear the same names as here given.3

These rules were in part adopted also by the International Botanical Congress held at Genoa in 1892, and by the Austro-German botanists at their meeting in September, 1904.

The Botanical Club of the American Association for the Advancement of Science adopted rules for Nomenclature at meetings held in 1892 and 1893, which were followed in our first edition.   An International Botanical Congress assembled at Vienna in 1905, and materially modified the Paris rules of 1867, and another Congress was held at Brussels in 1910.  In the present edition the Code of Nomenclature recommended by the American Commission in 1907, is closely followed, as above stated.


For a fuller discussion of this subject see articles

  • by Professor Lester F. Ward. in Bulletin of the Torrey Botanical Club, 22: 308-329, from which the above summary is mostly taken;
  • by Professor C. E. Bessey, in American Naturalist, 29: 666-668;
  • by Professor W. A, Kellerman, in Journal of the Columbus Horticultural Society, 10: 7-10, and in Botanical Gazette, 20: 468-470;
  • by Professor Conway MacMillan, in Metaspemlae of the Minnesota Valley, 17;
  • by Dr. B. L. Robinson, in Botanical Gazette, 20: 97-103,261-263;
  • by Dr. F. V. Cuville, in Botanical Gazette, 20: 162-167, 320-322, 428, 429;
  • by Dr. F. H. Knowlton, in Botanical Gazette, 21: 82-85.


The rules have been closely followed in the publications of

  • The United States National Museum;
  • the Divisions of Botany and Forestry of the United States Department of Agriculture;
  • The Missouri Botanical Garden;
  • The Torrey Botanical Club;
  • The University of Nebraska;
  • The Botanical Survey of Nebraska;
  • The Department of Botany of Columbia University;
  • The Geological and Natural History Survey of Minnesota;
  • The Botanical Survey of Indiana;

and many other societies and institutions.   Also in

  • Professor Sargent's Silva of North America;
  • Professor Underwood's Native Ferns and their Allies;
  • Professor Kellerman's Plants of Ohio;
  • Mr. Newhall's Shrubs of Northeastern America;

  and by a large number of other authors in less extensive writings.


Types of Genera and Species.

The critical study of plants, resulting in the present knowledge by botanists of many more genera and species than formerly, has made necessary more exact definition and determination of both genera and species by basing them on types, a method previously reached in zoology.   The following principles are contained in the Code of Nomenclature above referred to:

1. The nomenclatorial type of a species or subspecies is the specimen to which the describer originally applied the name in publication.
(a) When more than one specimen was originally cited, the type or group of specimens in which the type is included may be indicated by the derivation of the name from that of the collector, locality or host.
(b) Among specimens equally eligible, the type is that first figured with the original description, or in default of a figure the first mentioned.
(c) In default of an original specimen, that represented by the identifiable figure or (in default of a figure) description first cited or subsequently published, serves as the type.
2. The nomenclatorial type of a genus or subgenus is the species originally named or designated by the author of the name. If no species was designated, the type is the first binomial species in order eligible under the following provisions:
(a) The type is to be selected from a subgenus, section or other list of species originally designated as typical. The publication of a new generic name as an avowed substitute for an earlier invalid one does not change the type of a genus.
(b) A figured species is to be selected rather than an unfigured species in the same work. In the absence of a figure, preference is to be given to the first species accompanied by the citation of a specimen in a regularly published series of exsiccatae. In the case of genera adopted from prebinomial authors (with or without change of name), a species figured by the author from whom the genus is adopted should be selected.
(c) The application to a genus of a former specific name of one of the included species, designates the type.
(d) Where economic or indigenous species are included in the same genus with foreign species, the type is to be selected from (1) the economic species or (2) those indigenous from the standpoint of the original author of the genus.
(e) The types of genera adopted through citations of nonbinomial literature (with or without change of name), are to be selected from those of the original species which receive names in the first binomial publication. The genera of Linnaeus' Species Plantarum (1753) are to be typified through the citations given in his Genera Plantarum (1754).

In the present edition, the type species of genera are cited or otherwise indicated.


English Names of Plants.

The general desire for some English name to the different plants described has been met so far as possible. All names in common use have been inserted, so far as they have come to the authors' knowledge, except such as were merely local, or where they were too numerous for insertion. An exception has also been made in a few instances where a common name, from its false suggestion, as in the name of Dog's-tooth Violet for Adder's-tongue, is calculated to mislead as to the nature of the plant. Where no previous names in common use could be found, the names given are founded on some characteristic circumstance of description, habitat, site or author.

In the first edition, many thousand popular names, compiled mostly by Judge Brown, were printed in the General Index only. In this edition, they are all carried into the body of the work in their appropriate places in connection with the descriptive text-a great convenience to those interested in plant-nomenclature. A few additional common names are given in this edition.

No similar compilation of American plant-names has been hitherto published in any other work. Many of them are not to be found in any general dictionaries. To the mass of the people they will afford, in connection with the illustrations, the readiest means of plant identification.

The popular names are full of interest, from their origin, history and significance. Hundreds of them, brought to this country by the early English Colonists, are still in current use among us, though now obsolete in England. As observed in Britten and Holland's work cited below,

"they are derived from a variety of languages, often carrying us back to the early days of our country's history, and to the various peoples who as conquerors or colonists have landed on our shores and left an impress on our language. Many of these old-world words are full of poetical associations, speaking to us of the thoughts and feelings of the people who invented them; others tell of the ancient mythology of our ancestors, of strange old medicinal usages, and of superstitions now almost forgotten."

Most of these names suggest their own explanation. The greater number are either descriptive or derived from the supposed uses, qualities or properties of the plants; many refer to their habitat, appearance or resemblance real or fancied to other things; others come from poetical suggestion, affection or association With saints or persons. Many are very graphic, as the western name, Prairie Fire (Castilleja coccinea); many are quaint or humorous, as Cling-rascal (Galium Aparine) or Wait-a-bit (Smilax rotundifolia); and in some the corruptions are amusing, as Aunt Jerichos (N. Eng.) from Angelica. The words Horse, Ox, Dog, Bull, Snake, Toad are often used as a prefix to denote size, coarseness, worthlessness or aversion. Devil or Devil's is used as a prefix for upwards of 40 of our plants, mostly expressive of dislike or of some traditional resemblance or association. A number of names have been contributed by the Indians, such as Chinquapin, Wicopy, Pipsissewa. Wankapin, etc.; while the term Indian, evidently a favorite, is applied as a descriptive prefix to upwards of 80 different plants.

There should be no antagonism in the use of scientific and popular names, since their purposes are quite different. Science demands certainty and universality, and hence a single universal name for each plant. For this the Latin has been adopted, and the Latin name should be used, when only scientific objects are sought. But the vernacular names are a part of the growth and development of the language of each people. Though these names are sometimes indicative of specific characters and hence scientifically valuable, they are for the most part not at all scientific, but utilitarian. emotional or picturesque. As such, they are invaluable; not for science, but for the common intelligence, and the appreciation and enjoyment of the plant world. These names, in truth, reflect the mental attitude of each people, throughout its history, toward the plant kingdom; and the thoughts. suggestions. affections or emotions which it has aroused in them. If these are rich and multitudinous, as in the Anglo-Saxon race. so will the plant-names be also.

Usually the most common or the favorite plants have a variety of names; but this is noticeably otherwise with the Asters and the Golden-rods, of which there are about 125 species within our area, the common names of which, considering their abundance and variety, are comparatively few. The Golden-rods, without distinction, are also known as Yellow-weed or Yellow-tops; the Asters are called also Frost-weed, Frost-flowers, Good-bye Summer and by the Onondaga Indians, "it brings the Frost." A few like Aster ericoides have several interesting names, but most of the species in each genus resemble each other so much that not a quarter of the species have suggested to the popular apprehension any distinctive name; while other less showy plants, like the Pansy (Viola tricolor), the Marsh Marigold (Caltha palustris), the Spotted Touch-me-not (Impatiens biflora), Bluets (Houstonia coaulea) and others, have a score of different names.

In compiling these names, reference has been made to numerous general and special botanical works, to our state and local Floras, to Hobbs' Botanical Handbook (pharmaceutical), to Beal's, Scribner's and Pammel's works on Grasses, to Sudworth's Arborescent Flora, to Britten and Holland's Dictionary of English Plant Names (London, 1886), and to the valuable papers of Mrs. F. D. Bergen on Popular Plant Names in the Botanical Gazette for 1892, p. 365; for 1893. p. 420; for 1894. p. 429, and for 1896. p. 473. Prof. E. S. Burgess has also supplied about 100 popular names not before noted that are in use at Martha's Vineyard and in Washington. D.C.; and Mrs. Horner, of Georgetown, Mass., and Miss Bartlett, of Haverhill, Mass., have each contributed some.



In botanical names derived from Greek or Latin words, their compounds, or derivatives, the accent, according to the ordinary rule, is placed upon the penultimate syllable, if it is long in Latin quantity; otherwise, upon the antepenult. Many names, however, have been given to plants in honor of individuals, which, having nothing Latin about them except the terminal form, and the pronunciation given to them by botanical authors being diverse, are here accented like the names of the persons, so far as euphony will permit. This rule is followed because it is believed to agree with the prevailing usage among botanists in ordinary speech; because it is in accord with the commemorative object of such names, which ought not to be obscured by a forced and unnatural pronunciation; and because the test applied to words properly Latin, viz., the usage of the Latin poets, cannot be applied to words of this class. We therefore give Tórreyi, Vàseyi, Càreyi, Jàmesii, Álleni, rather than Torrèyi, Vasèyi, Carèyi, Jamèsii, Allèni.

The acute accent is used to denote the short English sound only; as in bát, bét, bíd, nót, nút; the grave accent, to denote either of the other English sounds, whether long, broad or open; as

  • a in bàle, bàll, bàr, bàre, làud;
  • e in ève, thère;
  • i in pìne, pìque, machìne;
  • o in nòte, mòve;
  • u in pùre, rùde.

The accent for the short or longer English sound is based upon current English usage, as given in the chief English dictionaries from Walker's to the most recent, and without reference to the supposed ancient pronunciation.

Much diversity has been found in botanical works in the accented syllable of many modern Latin adjectives ending in -inus, -ina, -inurn, derived from Latin words. As these adjectives are derived from Latin roots and are regularly formed, their pronunciation should properly follow classical analogies. When signifying, or referring to, time, material, or inanimate substances, they should, therefore, according to Andrews & Stoddard's rule, have the penult usually short, and the accent on the antepenult; as in gossípina, cannábina, secálina, salícina, amygdálina, and other adjectives derived from plant names, like the classic nárdinus, cýprinus, fáginus. When these adjectives have other significations than those above referred to, the penult under the ordinary Latin rule is usually long and accented; as in lupulìna, leporìna, hystricìna, like the classic ursìna, canìna.


The Use of Capital Letters.

In accordance with the recommendations of the Committee on Nomenclature of the Botanical Club of the American Association for the Advancement of Science, specific or varietal names derived from persons or places, or used as the genitive of generic names or as substantives, are printed with an initial capital letter. There is much difference of opinion as to the desirability of this practice, many botanists, and almost all zoologists, following the principle of writing all specific names with a small initial letter.   Should this custom prevail, much information concerning the history and significance of the specific names would be lost. Thus, in the Tulip-tree, Liriodendron Tulipifera, the specific name Tulipifera was the ancient generic name; and the same with Lythrum Salicaria, L. Hyssopifolia, L. Vulneraria, and many other species.  In all other forms of writing, personal adjectives such as Nuttallii, Engelmanni or Torreyi are printed with capitals. We adhere to the ordinary literary usage.



A general Key of the Orders and Families has been prepared by Dr. Britton according to the method followed in the Keys to the genera and species.   This general Key has been elaborated on the natural method, dividing the two subkingdoms of plants described in the work into Classes, Subclasses, Orders and Families successively.  The Orders are not described in the work itself, but their principal distinguishing characters are given in this key.  The natural method adopted necessitates a considerable number of exceptions to statements, owing to the varying degree of development of floral organs in the derivation of plants from their ancestors; these exceptions are either noted under the headings or indicated by cross-references.

In using this key, or any of the keys to genera or to species, the student will often find, in the analysis of a plant that it does not provide all the information necessary for its determination; this is generally owing to the incomplete condition of the specimen collected; it may be in flower, while the characteristic differences between it and others are only to be found in the fruit, or vice versa; or the species may be dioecious, or polygamous, when its other organs, perchance the characteristic ones, must be sought on another individual, and there are various other causes for incompleteness.   It is therefore earnestly recommended that collections be carefully made, seeking to reduce as far as possible this more or less necessary incompleteness.  Where satisfactory material can not be obtained, it will usually be found possible to reach the desired analysis by following out two or more lines of the key, and by comparing the results reached with the descriptions to determine the family, genus or species.  The illustrations provide an almost indispensable aid in such cases.


Assistance and Coöperation.

In the preparation of both the first edition and of the second we have had valued cooperation from many botanists, which is here gratefully acknowledged.

The late Professor Thomas C. Porter contributed much to the. first edition by suggestion, specimens, and the examination of proof sheets.

Mr. Eugene P. Bicknell has contributed specimens studied for both editions and read the proof sheets of the first.

Dr. John K. Small has assisted in the preparation of both editions, contributing the entire text of several families, and has read the proof sheets of the second.

The Pteridophyte text was contributed to the first edition by the late Professor Lucien M. Underwood, and to the second edition by Mr. William R. Maxon.

The text of the Grass Family has been written by Mr. George V. Nash for both editions.

Many of the drawings of grasses made by Mr. Theodore Holm for the first edition were supervised by Professor F. Lamson Scribner.

The late Mr. Charles E. Smith critically examined the final proof sheets of the first edition.

Mr. Frederick V. Coville has contributed the text of Juncaceae to both editions.

The late Dr. Thomas Morong wrote the text of several families for the first edition.

The text of the Carrot Family in both editions has been examined by Dr. J. N. Rose.

Most of the drawings for the first edition were supervised by Dr. Arthur Hollick.

For the second edition Mr. Kenneth K. Mackenzie has contributed the text of Carex, and supplied many specimens for study; Mr. W. W. Eggleston has written the text of Cralaegus; Dr. Ezra Brainerd has written the text of Viola; Dr. Per Axel Rydberg has aided in the determination of specimens; and many others have aided by specimens, notes and information.



Most of the drawings have been executed by Mr. F. Emil; he has made all the figures of the Pteridophyta, Gymnospennae, and nearly all of the Monocotyledones, with the exception of those of Gramineae, Melanthaceae, Liliaceae and Convallariaceae; also nearly all of the apetalous Choripetalae, and a considerable portion of the Sympetalae. Miss Millie Timmerman (now Mrs. Heinrich Ries) drew the bulk of the polypetalous Choripetalae, the enlarged parts being mostly inserted by Mr. Arthur Hollick; she also did some work on several of the sympetalous families. Mr. Joseph Bridgham drew the Melanthaceae, Liliaceae and Convallariaceae; also the Ericaceae, Primulaceae and several related families. Mr. Theodor Holm drew most of the Gramineae. Mr. Hollick has made some drawings and numerous enlargements of special parts throughout the work. Miss Mary Knight and Mr. Rudolph Weher have also contributed drawngs.

The additional drawings needed for the second edition, and some corrections of the old ones, have been made by Mr. A. Mariolle, Miss Mary E. Eaton and Miss Rachel Robinson.

New York,
  April 15, 1913.