DOI Ce & Gar Se : 208) | : | ; chem v nited : ALBERT R. MANN LIBRARY New York STATE COLLEGES OF AGRICULTURE AND HoME ECONOMICS AT CoRNELL UNIVERSITY Trees of the northern United States :the Tit Cornell University Library The original of this book is in the Cornell University Library. There are no known copyright restrictions in the United States on the use of the text. http://www.archive.org/details/cu3 1924003507799 TREES OF THE NORTHERN UNITED STATES THEIR STUDY, DESCRIPTION AND DETERMINATION FOR THE USE OF SCHOOLS AND PRIVATE STUDENTS BY AUSTIN C. APGAR PROFESSOR OF BOTANY IN THE NEW JERSEY STATE NORMAL SCHOOL NEW YorK STA COLLEGE OF AGRICULTURE BEPARTMENT OF FLORIGULTURE A‘ TQ are God’s Architecture.”—Anonymous. a lent who has learned to observe and describe so simple a ORNA MM 88 pt ined a power which will be e ft M Ay be his sphere of professional Cc fe) R N ED un »— Wm. North Rie LL UNIVES cI FY ITHACA, M. ¥ NEW YORK «:- CINCINNATI -:- CHICAGO AMERICAN BOOK COMPANY Copyright, 1892, by AMERICAN Book Company, Copyright, 1920, by ADA APGAR Draycorr, Ww. P. 28 PREFACE. HIS book has been prepared with the idea that teachers generally would be glad to introduce into their classes work dealing with the real objects of nature, provided the work chosen were of a character that would admit of its being studied at all seasons and in all localities, and that the subject were one of general interest, and one that could be taught suc- cessfully by those who have had no regular scientific instruction. The trees of our forests, lawns, yards, orchards, streets, bor- ders, and parks g:ve us just such a department. Though many consider a large part of the vegetable kingdom of little impor- tance, and unworthy of any serious study, there are few who do not admire, and fewer still who do not, desire to know, our trees, the monarchs of all living things. The difficulty in tree study by the aid of the usual botanies lies mainly in the fact that in using them the first essential parts to be examined are the blossoms: and their organs. These remnain on the trees a very short time, are often entirely unnoticed on account of their small size or obscure color, and are usually inaccessible even if seen. In this book the leaves, the wood, the bark, and, in an elementary way, the fruit are the parts to which the attention is directed; these all can be found and studied throughout the greater part of the year, and are just the parts that must be thoroughly known by all who wish to learn to recognize trees. Though every teacher is at liberty to use the book as he thinks best, the author, who has been a class teacher for over twenty years, is of the opinion that but little of Part I. need be 3 4 PREFACE thoroughly studied and recited, with the exception of Chapter III. on leaves. The object of this chapter is not to have the definitions recited (the recitation of definitions in school work is often useless or worse than useless), but to teach the pupil to use the terms properly and to make them a portion of his vocabulary. The figures on pages 38-43 are designed for class description, and for the application of botanical words. The first time the chapter is studied the figure illustrating the term should be pointed out by the pupil; then, as a review of the whole chapter, the student should be required to give a full description of each leaf. After this work with Chapter III., and the careful reading of the whole of Part I., the pupils can begin the description of trees, and, as the botanical words are needed, search can be made for them under the proper heads or in the Glossary. The Keys are for the use of those who know nothing of scien- tific botany. The advanced botanist may think them too arti- ficial and easy; but let him remember that this work was written for the average teacher who has had no strictly scien- tific training. We can hardly expect that the great majority of people will ever become scientific in any line, but it is pos- sible for nearly every one to become interested in and fully acquainted with the trees of his neighborhood. The attainment of such botanical knowledge by the plan given in this volume will not only accomplish this useful purpose, but will do what is worth far more to the student, i. e., teach him to employ his own senses in the investigation of natural objects, and to use his own powers of language in their description. With hardly an exception, the illustrations in the work are taken from original drawings from nature by the author. A few of the scales of pine-cones were copied from Loudon’s “ En- cyclopedia of Trees”; some of the Retinospora cones were taken from the ‘‘Gardener’s Chronicle”; and three of the illustrations in Part I. are from Professor Gray’s works. PREFACE +] The size of the illustration as compared with the specimen of plant is indicated by a fraction near it; + indicates that the drawing is one fourth as long as the original, t that it is nat- ural size, etc. The notching of the margin is reduced to the same extent; so a margin which in the engraving looks about entire, might in the leaf be quite distinctly serrate. The only cases in which the scale is not given are in the cross-sections of the leaves among the figures of coniferous plants. These are uniformly three times the natural size, except the section of Araucaria imbricata, which is not increased in scale. The author has drawn from every available source of infor- mation, and in the description of many of the species no attempt whatever has been made to change the excellent wording of such authors as Gray, Loudon, ete. The ground covered by the book is that of the wild and cul- tivated trees found east of the Rocky Mountains, and north of the southern boundary of Virginia and Missouri. It contains not only the native species, but all those that are successfully cultivated in the whole region; thus including all the species of Ontario, Quebec, etc., on the north, and many species, both wild and cultivated, of the Southern States and the Pacific coast. In fact, the work will be found to contain so large a proportion of the trees of the Southern States as to make it very useful in the schools of that section. Many shrubby plants are introduced; some because they oc- casionally grow quite tree-like, others because they can readily be trimmed into tree-forms, others because they grow very tall, and still others because they are trees in the Southern States. In nomenclature a conservative course has been adopted. The most extensively used text-book on the subject of Botany, “ Gray’s Manual,” has recently been rewritten. That work in- cludes every species, native and naturalized, of the region covered by this book, and the names as given in that edition have been used in all cases. 6 PREFACE Scientific names are marked so as to indicate the pronuncia- tion. The vowel of the accented syllable is marked by the grave accent (') if long, and by the acute (’) if short. In the preparation of this book the author has received much valuable aid. His thanks are especially due to the authorities of the Arnold Arboretum, Boston, Massachusetts, and of the Missouri Botanical Garden, St. Louis, for information in regard to the hardiness of species; to Mr. John H. Redfield, of the Botanical Department of the Philadelphia Academy of Nat- ural Sciences, for books, specimens from which to make illus- trations, etc.; and to Dr. A. C. Stokes, of Trenton, New Jersey, for assistance in many ways, but especially for the accurate manner in which he has inked the illustrations from the au- thor’s pencil-drawings. The author also wishes to acknowledge the help received from many nurserymen ‘in gathering specimens for illustra- tion and in giving information of great value. Among these, special thanks are due to Mr. Samuel C. Moon, of Morrisville Nurseries, who placed his large collection of living specimens at the author’s disposal, and in many other ways gave him much intelligent aid. CONTENTS. PARTI. EssentiaL ORGANS, AND TERMS NEEDED FOR THEIR DESCRIPTION.......... 00. .eeeeeee CHAPTER I... CHaPTeR II. . CHAPTER ITI... Cuaprer IV. . CHAPTER V... CHAPTER VI.. CHAPTER VII. seription ... Winter Study of Trees............ The Preparation of a Collection .. Figures to be used in Botanical De- PART II. Puan anD MODELS FOR TREE DESCRIPTION PART III. Key, CLASSIFICATION AND DESCRIPTION OF THE SPECIES............. 000 cc eee eee 38 44-50 51-201 GLOSSARY OF BoTANICAL TERMS, AND INDEX TO PARTI 203-212 InpEx To Part IIL .................. DR ealaws Oo 213-224 AT PART IL. THE ESSENTIAL ORGANS, AND THE TERMS NEEDED FOR THEIR DESCRIPTION. CHAPTER I. Roots. HOUGH but little study of the roots of trees is prac- ticable, some knowledge of their forms, varieties, and parts is important. The great office of the roots of all plants is the taking in of food from the soil. Thick or fleshy roots, such as the radish, are stocks of food prepared for the future growth of the plant, or for the production of flowers and fruit. The thick roots of trees are designed mainly for their secure fastening in the soil. The real mouths by which the food is taken in are the minute tips of the hair- like roots found over the surface of the smaller branches. As trees especially need a strong support, they all have either a tap-root—one large root extending from the lower erd of the trunk deep down into the ground; or multiple roots —a number of large roots mainly extend- ing outward from the base of the trunk. Trees with large tap-roots are very hard to transplant, and cannot with safety be transferred after they have at- tained any real size. The Hickories and Oaks belong to this class. 9 ‘ 10 TREES OF THE NORTHERN UNITED STATES Trees having multiple roots are readily transplanted, even when large. The Maples and Elms are of this class. Roots that grow from the root-end of the embryo of the seed are called primary roots; those growing from slips or from stems anywhere are secondary roots. Some trees grow luxuriantly with only secondary roots ; such trees can readily be raised from stems placed in the ground. The Willows and Poplars are good examples of this group. Other trees need all the strength that primary roots can give them; these have to be raised from seed. Peach-trees are specially good examples, but practically most trees are best raised from seed. A few trees can be easily raised from root-cuttings or from suckers which grow up from roots. The Ailanthus, or “Tree of Heaven,” is best raised in this way. Of this tree there are three kinds, two of which have disagree- able odors when in bloom, but the other is nearly odor- less. By using the roots or the suckers of the third kind, only those which would be pleasant to have in a neighbor- hood would be obtained. One of the large cities of the United States has in its streets thousands of the most, displeasing of these varieties and but few of the right sort, all because the nurseryman who originally supplied the city used root-cuttings from the disagreeable kind. If such trees were raised from the seed, only about one third would be desirable, and their character could be determined only when they had reached such a size as to produce fruit, when it would be too late to transplant them. Fruit-trees, when raised from the seed, have to be grafted with the desired variety in order to secure good fruit when they reach the bearing age. CHaprer II. Stems and Branches. THE stem is the distinguishing characteristic of trees, separating them from all other groups of plants. Although in the region covered by this book the trees include all the very large plants, size alone does not make a tree. A plant with a single trunk of woody structure that does not branch for some distance above the ground, is ealled a tree. Woody plants that branch directly above the soil, even though they grow to the height of twenty feet or more, are called shrubs, or, in popular language, bushes. Many plants which have a tendency to grow into the form of shrubs may, by pruning, be forced to grow tree-like; some that are shrubs in the northern States are trees further south. All the tees that grow wild, or can be cultivated out of doors, in the northern States belong to one class, the stems having a separable bark on the outside, a minute stem of pith in the center, and, between these, wood in annual layers. Such a stem is called exogenous (outside-growing), because a new layer forms on the outside of the wood each year. Another kind of tree-stem is found abundantly in the tropics; one, the Palmetto, grows from South Carolina to Florida. While in our region there are no trees of this character, there are plants having this kind of stem, the best illustration being the corn-stalk. In this case there is no separable bark, and the woody substance is in threads within the pithy material. In the corn-stalk the woody threads are not very numerous, and the pith is very abun- dant; in most of the tropical trees belonging to this group the threads of wood are so numerous as to make the ma- 11 12 TREES OF THE NORTHERN UNITED STATES terial very durable and fit for furniture. A stem of this kind is called endogenous (inside-growing). Fig. 1 repre- sents a longitudinal and a cross section of an exogenous stem, and Fig. 2 of an endogenous one. Since all the stems with which we have to deal are exogens, a particular description of that class will here H] be given. Fig. 1 shows ‘WW the appearance of a section of an Ash stem six years old. The central portion, which is about as thick as wrapping-twine, is the pith; from this outward toward the bark can be seen the six annual layers of the wood ; and then comes the bark, con- sisting of two portions. First there is an inside layer of greenish material, the fresh-growing portion, and lastly the outer or dead matter. This outer portion“must crack open, peel off, or in some way give a chance for the con- stant growth of the trunk. The different kinds of trees are readily known by the appearance of the bark of the trunk, due to the many varieties of surface caused by the allowance for growth. None of the characteristics of trees afford a better opportunity for careful observation and study than the outer bark. The Birches have bark that peels off in thin horizontal layers—the color, thinness, and toughness differing in the different species; the Ashes have bark which opens in many irregular, netted cracks moderately near each other; the bark of the Chestnut opens in large longitudinal cracks quite distant from one another. The color of the bark and the character of the scales are quite different in the White and the Black Oaks. In the woody portion radiating lines may be seen; STEMS AND BRANCHES 12 these are the silver grain ; they are called by the botanist medullary rays. The central portion of the wood of many large stems is darker in color than the rest. This darker portion is dead wood, and is called heart-wood ; the outer portion, called sap-wood, is used in carrying the sap during the growing season. The heart-wood of the Walnut-tree is very dark brown; that of the Cherry, light red; and that of the Holly, white and ivory-like. The heart-wood is the valu- able part for lumber. : If examined under a magnifying glass, the annual layers will be seen to consist of minute tubes or cells. In most trees these tubes are much larger in the portion that grew early in the season, while the wood seems almost solid near the close of the annual layer; this is especially true in the Ashes and the Chestnut; some trees, however, show but little change in the size of the cells, the Beech being a good example. In a cross-section, the age of such trees as the Chestnut can readily be estimated, while in the Beech it is quite difficult to do this. Boxwood, changing least in the character of its structure, is the one always used for first-grade wood-engravings. When wood is cut in the direction of the silver grain, or cut “ quartering” as it is called by the lumbermen, the surface shows this cellular material spread out in strange blotches characteristic of the different kinds of wood. Fig. 16 shows an Oak where the blotches of medullary rays are large. In the Beech the blotches are smaller; in the Elm quite small. Lumber cut carefully in this way is said to be “ quartered,” and with most species its beauty is thereby much increased. Any one who studies the matter carefully can become acquainted with all the useful and ornamental woods used in a region; the differences in the color of the heart- wood, the character of the annual layers, and the size and the distribution of the medullary rays, afford enough peculiarities to distinguish any one from all others. {4 TREES OF THE NORTHERN UNITED STATES BRANCHING.—The regular place from which a branch grows is the azil of a leaf, from what is called an azillary bud ; but branches cannot grow in the axils of all leaves. A tree with opposite leaves occasionally has opposite branches; while a tree with alternate leaves has all its branches alternate. Most branches continue their growth year after year by the development of a bud at the end, called a terminal bud. Many trees form this bud for the next year’s growth so early in the year that it is seldom or never killed by the winter weather; such trees grow very regularly and are symmetrical inform. Most evergreens are good ex- . amples. Fig. 3 represents " agood specimen. The age , of such trees, if not too great, can be readily ascer- tained by the regularity of each year’s growth. The tree represented is sixteen Fig. 3. years old. The branches that started the fifth year, about the age at which regular growth begins, are shown by their sears on the trunk. The terminal buds of many trees are frequently killed by the frosts of winter; such trees continue their growth by the development of axillary buds; but as growth from an axillary bud instead of a terminal one will make a branch crooked, such trees are irreyular in their branch- ing and outline. Just which axillary buds are most apt to grcw depends upon the kind of tree, but trees of the same variety are nearly uniform in this respect. Most trees are therefore readily recognized by the form of outline and the characteristic branching. A good example of a tree ‘ STEMS AND BRANCHES lo of very irregular growth is the Catalpa (Indian Bean), shown in Fig. 4. The tendency to grow irregularly usually increases with age. The Buttonwood, for ex- ample, grows quite regu- : larly until it reaches the ae age of thirty to forty ~.2ick years; then its new = branches grow in pecu- liarly irregular ways. The twigs of a very old and a young Apple-tree illustrate this change which age produces. — There are great differ- ences in the color and surface of the bark of the twigs of different species of trees; some are green (Sassafras), Fig. +. some red (Peach, on the sunny side), some purple (Cherry). Some are smooth and dotless, some marked with dots (Birch), some roughened with corky ridges (Sweet Gum), ete. The taste and odor of the bark are characteristics worthy of notice: the strong, fragrant odor of the Spice- bush; the fetid odor of the Papaw; the aromatic taste of the Sweet Birch; the bitter taste of the Peach; the mu- cilaginous Slippery Elm; the strong-scented, resinous, aromatic Walnut, ete. The branches of trees vary greatly in the thickness of their tips and in their tendency to grow erect, hori- zontal, or drooping. Thus the delicate spray of the Birches contrasted with the stout twigs of the Ailanthus, or the drooping twigs of the Weeping Willow with the erect growth of the Lombardy Poplar, give contrasts of the strongest character. In the same way, the direc- tions the main branches take in their growth from the 16 TREES OF THE NORTHERN UNITED STATES trunk form another distinctive feature. Thus the up- ward sloping branches of the Elm form a striking con- trast to the horizontal or downward sloping branches of the Sour Gum, or, better still, to certain varieties of Oaks. When the main trunk of a tree extends upward through the head to the tip, as in Fig. 3, it is said to be excurrent. When it is soon lost in the division, as in Fig. 4, it is said to be deliquescent. Cuaprer III. Leaves. LEAVES are the lungs of plants. The food taken in by the roots has to pass through the stem to the leaves to be acted upon by the air, before it becomes sap and is fit to be used for the growth of the plant. No portion of a plant is more varied in parts, forms, surface, and dura- tion than the leaf. No one can become familiar with leaves, and appreciate their beauty and variety, who does not study them upon the plants themselves. This chapter therefore will be devoted mainly to the words needed for leaf description, together with their application. THE Lear.—In the axil of the whole leaf the bud forms for the growth of a new branch. So by noting the position of the buds, all the parts included in a single leaf can be determined. As a general thing the leaf has but one blade, as in the Chestnut, Apple, Elm, ete.; yet the Horse-chestnut has 7 blades, the Common Locust often has 21, and a single leaf of the Honey-locust occasionally has as many as 300. Figs. 17-58 (Chapter VIL.) are all illus- trations of single leaves, except Fig. 48, where there are two leaves on a twig. A number of them show the bud by which the fact is determined (Figs. 25, 26, 31, 33, 34, 36, 40, ete.); others show branches which grew from the ax- illary buds, many cf them fruiting branches (Figs. 37, 42, 43, 50, and 54), one (Fig. 51) a thorny branch. The cone-bearing plants (Figs. 59-67) have only sim- ple leaves. Each piece, no matter how small and scale- like, may have a branch growing from its axil, and so may form a whole leaf. A study of these figures, together D) 7 18 TREES OF THE NORTHERN UNITED STATES with the observation of trees, will soon teach the student what constitutes a leaf. ARRANGEMENT.— There are several different ways in which leaves are arranged on trees; the most common plan is the alternate ; in this only one leaf occurs ata joint or node onthe stem. The next in frequency is the opposite, where two leaves opposite each otber are found at the node. A very rare arrangement among trees, though common in other plants, is the whorled, where more than two leaves, regularly ar- ranged around the stem, are found at the node. When a number of leaves are bundled together,—a plan not rare among evergreens,— they are said to be fascicu- lated or in fascicles. aaa The term scattered is used where alternate leaves are crowded on the stem. This plan is also common among evergreens. Caution. — In some plants the leaves on the side shoots or spurs of a twig are so close together, the inter- nodes being so short, that at first sight they seem opposite or clustered. In such cases, the leaf-scars of the pre- ceding years, or the arrangement of the branches, is a. better test of the true arrange- ment of the leaves. The Fig. 5. ‘twig of Birch shown in Fig. 5 has alternate leaves. There is one variety of alterna- SN tion, called two-ranked, which is quite characteristic of certain trees; aS Ue Ui that is, the leaves are so flattened ee 1 T out as to be in one plane on the opposite sides of the twig (Fig. 6). The Elm-trees form good examples Fig. 6. aig LEAVES 19 of two-ranked alternate leaves, while the Apple leaves are alternate without being two-ranked. Most leaves spread from the stem, but some are appressed, as in the Arbor-vite (Fig. 7). In this spe- cies the branches are two-ranked. Parts or Leaves.— A complete leat ~€£ consists of three parts: the blade, the thin expanded por- tion; the petiole, the leafstalk; and the stipules, a pair of small blades at the base of the petiole. The petiole is often very short and sometimes wanting. The stipules are often absent, and, even when present, they frequently fall off as soon as the leaves expand; some- times they are conspicuous. Most Willows show the stipules on the young luxuriant growths. VEINING.— The leaves of most trees have a distinct framework, the central line of which is called a midrib ; sometimes the leaf has several other lines about as thick as the midrib, which are called ribs ; the lines next in size, includ- ing all that are especially distinct, Fig. 8. are called veins, the most minute ones being called veinlets (Fig. 8). Kinps.— Leaves are simple when they have but one blade; compound when they have more than one. Compound vo in the Hickory. Pinnate leaves are of two kinds: odd- 20 TREES OF THE NORTHERN UNITED STATES pinnate, when there is an odd leaflet at the end, as in the Ash, NQN™ and abruptly pinnate 4 when there is no end leaflet. Many trees have the leaves twice pinnate; they are either twice odd-pinnate or twice abruptly pinnate., , The separate blades of a compound leaf are sasrex called leaflets. Leaves or leaflets are sessile when “yt have no stems, and petiolate when they have stems. When there are several ribs starting together from the base of a blade, it is said to be radiate- veined or palmate-veined.. When the great veins all branch from the midrib, the leaf is feather-veined or pinnate-veined. If these veins are straight, distinct, and reg- ularly placed, the leaf is said to be straight- veined. The Chestnut is a good example. Leaves having veialets join- ing each other like a net are said to be netted-veined. All the trees with broad leaves in the northern United States, with one ex- ception, have netted-veined foliage. A leaf having its veinlets parallel to one another is said to be parallel- veined or -nerved. The Ginkgo-tree, the Indian Corn and the Calla Lily have parallel-veined leaves. ——« The narrow leaves of the cone-bearing trees are | also parallel-veined. Forms.—Leaves can readily be divided into the three following groups with regard to their general outline: 1. Broadest at the middle. Orbicular, aboutas broad as long and rounded. Oval, about Sed twice as long as wide, and regularly curved. Elliptical, <=> ' more than twice as long as wide, and evenly curved. Oblong, 27) two or three times as long as wide, with the sides parallel. Linear, elongated oblong, more than three times as long as wide. Acerose, a needle-shaped, like the leaf of the Pine-tree. LEAVES 21 2. Broadest near the base. Deltoid, \ broad and tri- angular. Ovate, evenly curved, with a broad, rounded base. 7 Heart-shaped or cordate, similar to ovate, but with a notch at the base. Lan- ceolate, EZ, shaped like the head of a lance. Avwi- shaped, ete shaped like the shoemaker’s curved awl. Scale- shaped, _, Short, rounded, and ap- pressed to the stem. The E. Arbor-vite has both awl-shaped and_ scale- shaped leaves. 3. Broadest near the apex. Obovate, same as ovate, but with the stem at the narrow end. Obcordate, a reversed heart-shape. Oblanceolate, =< > a mV) versed lanceolate. Wedge-shaped or cuneate, ee) having a somewhat square end and straight sides like a wedge. These words are often united to form compound ones when the form of the leaf is somewhat intermediate. The term which most nearly suits the general form is placed at the end; thus lance-ovate indicates a leaf between lanceolate and ovate, but nearer ovate than lanceolate; while ovate-lanceolate indicates one nearer lanceolate. Bases.— Oftentimes leaves are of some general form, but have a peculiar base, one that would not be expected from the statement of shape. An ovate leaf which should have a rounded base might have a tapering one; it would then be described as ovate with a tapering base. Ke A lanceolate leaf should naturally have a tapering base, but might have an abrupt one. Ce Many leaves, no matter what their general form may be, have more or less notched bases; such bases are called cor- date, -. deeply or slightly, as the case may be; and if the lobes at base are elongated, awriculate. If the basal lobes project outward, the term halberd- shaped is used. Any form of leaf may ftw have 7/7 a base more or less oblique. & IZ 22, TREES OF THE NORTHERN UNITED STATES Ports.— The points as well as the bases of leaves are often peculiar, and need to be described by appro- priate terms. Truncate indicates an end that is square; retuse, /¥ |Z Sy one with a slight notch; emarginate, one —* “with a decided notch; 0d- cordate, with a still deeper notch; obtuse, << angular but abrupt; acute, <= somewhat sharp- >“ ened ; acumi- nate, He, de- *s cidedly sharp-pointed ; bristle-pointed and * with a short, abrupt point. Mareins.— Entire, 455 edge without notches; re- pand, slightly = wavy; sinuate, de- CS aie wavy ; dentate, with > tooth-like notches; serrate, 772» with notches like those of a saw; = crenate, ©, with the teeth rounded; twice ser- rae Se when there are coarse serrations finely ser- rated, as on most Birch leaves; serrulate, with minute serra- tions; erenulate, with minute crenations. Leaves can be twice crenate or sinuate-crenate. Revolute indicates that the edges are rolled over. When a leaf has a few great teeth, the projecting parts are called lobes, and the general form of the leaf is what it would be with the notches filled in. In the description of such leaves, certain terms are needed in describing the plan of the notches, and their depth and form. Leaves with palmate veining are palmately lobed or notched ; those with pinnate veining are pin- nately lobed er notched. While the term lobe is applied to all great teeth of a leaf, whether rounded or pointed, long or short, still there are four terms sometimes used having special signification with reference to the depth of the notches. Zobed indicates that the notches extend about one fourth the distance tc the base or midrib; cleft, that they extend one half the LEAVES 23 way; parted, about three fourths of the way ; and divided, that the notches are nearly deep enough to make a com- pound leaf of separate leaflets. So leaves may be palmately lobed, cleft, parted or di- vided, and pinnately lobed, cleft, parted or divided. The term pinnatifid is often applied to pinnately cleft leaves. The “ARR? terms entire, serrate, crenate, acute-pointed, etc., are applied to the lobes as well as to the general margins of leaves. SurFace.—The following terms are needed in describ- ing the surface of leaves and fruit. Glabrous, smooth; glaucous, covered with a whitish bloom which can be rubbed off (Plum); rugous, wrin- kled ; canescent, so covered with minute hairs as to appear silvery; pubescent, covered with fine, soft, plainly seen hairs; tomentose, densely covered with matted hairs; hairy, having longer hairs; scabrous, covered with stiff, ~seratching points; spiny, having stiff, sharp spines; glan- dular-hairy, having the hairs ending in glands (usually needing a magnifying glass to be seen). TEXTURE.— Succulent, fleshy ; scarious, dry and chaffy ; punctate, having translucent glands, so that the leaf ap- pears, when held toward the light, as though full of holes; membranous, thin, soft, and rather translucent; thick, thin, ete. Duration.— Evergreen, hanging on the tree from year to year. By noticing the color of the different leaves avd their position on the twigs, all evergreen foliage can readily be determined at any time during the year. Deciduous, falling off at the end of the season. Fuga- cious, falling early, as the stipules of many leaves. CuHarter IV. Flowers and Fruit. Tue author hopes that those who use this work in studying trees will become so much interested in the subject of Botany as to desire more information concern- ing the growth and reproduction of plants than can here be given. In Professor Asa Gray’s numerous works the additional information desired may be obtained: “ How Plants Grow” contains an outline for the use of begin- ners; “The Elements of Botany” is a more advanced work; while the “ Botanical Text Book,” in several vol- umes, will enable the student to pursue the subject as far as he may wish. In this small book the barest outline of the parts of flowers and fruit and of their uses can be given. FLOWERS.— Parts. The flowers of the Cherry or Apple will show the four kinds of organs that belong to a com- plete flower. Fig. 9 represents an Apple-blossom. The ca- lyx is the outer row of leaves, more or less united into one piece. The corolla is the row of leaves within the calyx; it 7 is usually the brightest and most conspicuous part of the flower. The stamens == are the next organs; they are usually, as in this case, small two-lobed bodies on slender, thread-like stalks. The en- larged parts contain a dust- like material called pollen. m4 FLOWERS AND FRUIT > 25 The last of the four kinds of parts is found in the center of the flower, and is called the pistil. Itis this part which forms the fruit and incloses the seed. The stamens and the pistil are the essential organs of a flower, because they, and they only, are needed in the for- mation of seeds. The pollen from the stamen, acting on the pistil, causes the ovules which are in the pistil to grow into seeds. The calyx and corolla are called enveloping organs, since they surround and protect the essential parts. The pieces of which the calyx is composed are called sepals. The Apple-blossom has five sepals. The pieces that compose the corolla are called petals. Kinps oF FLOWERS.—When the pelnls. & are entirely separate from each other, as in the Apple-blossom, the flower is said to be gas polypetalous ; when they grow together © more or less, as in the Catalpa (Fig. 10), € monopetalous ; and when the corolla is ~ Fig. 10. wanting, as in the flowers of the Oak, apetalous. When all sides of a flower are alike, as in the Apple- blossom, the flower is regular; when one side of the corolla differs from the other in color, form, or size, as in the Common Locust, or Catalpa, the flower is irregular. In trees the stamens and pistils are often found in separate flowers; in that case the blossoms containing stamens are called staminate, and those containing pistils pistillate; those that contain both are called perfect. Staminate and pistillate flowers are usually found on the same tree, as in the Oaks, Birches, Chestnut, ete.; in that case the plant is said to be monecious, and all trees of this kind produce fruit. Sometimes, however, the stam- inate and pistillate flowers are on separate trees, as .in the Willows, which are diwcious; and then only a por- tion of the trees—those with pistillate flowers— produce fruit. 26 TREES OF THE NORTHERN UNITED STATES ARRANGEMENT OF FLOwERS.— Flowers, either solitary or clustered, grow in one of two ways; either at the end of the branches, being then called terminal, or in the axils of the leaves, then called azillary. The stem of a solitary flower or the main stem of a cluster is called a pedunele ; the stems of the separate blossoms of a cluster are called pedicels. When either the flowers or the clusters are without stems, they are said to be sessile. Clusters with Petlicellate Flowers. Raceme, “eae flowers on pedicels of about equal length, scattered along the entire stem. Locust-tree. Corymb, like a raceme except that the lower flowers have longer stems, making the cluster some- what flat-topped; the outer flowers bloom first. Hawthorn. Cyme, Va in appearance much like a corymb, but it differs in / the fact that the central flower blooms first. Alternate-leaved Cornel. Umobel, ~@ stems of the separate flowers about equal in length, and starting from the same point. Gar- den-cherry. Panicle, Be. a compound raceme. Catalpa. Thyrsus, a compact panicle. Horse-chestnut. Clusters with Sessile or Nearly Sessile Flowers. Cathkin, x, bracted flowers situated along a slender andusual-gy }} ly drooping stem. This variety of clus- terisvery 4® § common on trees. The Willows, Birches, Chestnuts, Oaks, Pines, and many others have their flow- ers in catkins. Aes: the flowers in a close, usually rounded Fl cluster. owering Dogwood. Fruit.—In this book a single fruit will include all the parts that grow together and contain seeds, whether from FLOWERS AND FRUIT 27 a single blossom or a cluster; there will be no rigorous adherence to an exact classification; no attempt made to distinguish between fruits formed from a simple pistil and those from a compound one; nor generally between those formed from a single and those formed from a clus- ter of flowers. The fruit and its general classification, determined by the parts easily seen, is all that will be attempted. As stated before, it is hoped that this volume will not end the student’s work in the investigation of natural objects, but that the amount of information here given will lead to the desire for much more. Berry will be the term applied to all fleshy fruits with more than one seed buried in the mass. Persimmon, Mul- berry, Holly. The pome or Apple-pome differs from the berry in the fact that the seeds are situated in cells formed of hardened material. Apple, Mountain-ash. The Plian or Cherry drupe includes all fleshy fruits with a single stony-coated part, even if it contains more than one seed. Peach, Viburnum, China-tree. In some cases, when there is but one seed in the flesh and that not stony-coated, it will be called a drupe-like berry. The dry drupe is like the Cherry drupe except that the flesh is much harder. The fruit of the Walnut, Hickory, and Sumac. The inner hard-coated parts of these and some others will be ealled nuts. Ifthe nuthasapar- | tial sealy covering, as in the Oaks, / the whole forms an acorn. @& }) If the coating has spiny « hairs, as in the Chestnut and Beechnut, the wholeisabur. The coating in these cases is an in- volucre. If the coating or any part of the fruit has a regular place for splitting open, it is de- 28 TREES OF THE NORTHERN UNITED STATES hiscent (Chestnut, Hickory-nut) ; if not, indehiscent (Black Walnut). Dry fruits with spreading, wing-like appendages, as in the Ash (Fig. 11), Maple (Fig. 12), Elm (Fig. 13), and Ailanthus, are called sa- maras or keys. 4 Dry fruits, usually elongated, contain- je ing generally several seeds, are called ts pods. Tf there is but one cell and the # ‘ seeds are fastened along one side, Pea- 4 like pods, or legumes. Locust. The term Fig. 12, capsule indicates that there is more than one cell. Catalpa, Hibiscus. All the dry, scaly fruits, usually formed by the ripening of some sort of catkin of flowers, will be included under the term cone. Pine, Alder, Magnolia. If the appear- ance of the fruit is not much e different from that of the cluster of flowers, as in the Hornbeams, Wil- lows, and Birches, the term catkin will be retained for the fruit also. The scales of a cone may lap over each other; they are then said to be imbricated or over- lapping, @&®-» (Pine); or they may merely “WS” touch at their edges, when they are valvate (Cypress). When cones or @ catkins hang downward, the. are pendent. If the scales have projecting points, these points are spines if strong, and: prickles it weak. The parts back of the scales are bracts; these often project Fig. 13. beyond the scales, when they are said to be exserted. % Sometimes the exserted bracts are bent backward ; \ they are then said to be recurved or reflexed. CHAPTER V. Winter Study of Trees. Many of the peculiarities of trees can be studied much better during the winter and early spring than at any other time of the year. The plan of branching, the posi- tion, number, size, form, color, and surface of buds, as well as the arrangement of the leaves within the bud and the peculiarities of the scales that cover them, are points for winter investigation. GENERAL PLAN OF BRANCHING.—There are two dis- tinct and readily recognized systems of branching. 1. The main stem is excurrent (Fig. 8) when the trunk extends as an undivided stem throughout the tree to the tip; this causes the spire-like or conical trees so common among narrow-leaved evergreens. 2. The main stem is deliques- cent (Fig. 4) when the trunk divides into many, more or Jess equal divisions, forming the broad-topped, spreading trees. This plan is the usual one among deciduous trees. A few species, however, such as the Sweet Gum and the Sugar-maple, show the excurrent stem while young, yet even these have a deliquescent stem later in life. The English Maple and the Apple both have a deliquescent stem very early. All the narrow-leaved evergreens, and many of the broad-leaved trees as well, show what is called definite annual growths; that is, a certain amount of leaf and stem, packed up in the winter bud, spreads out and hard- ens with woody tissue. early in the year, and then, no matter how long the season remains warm, no additional leaves or stem will grow. The buds for the next year’s 29 30 TREES OF THE NORTHERN UNITED STATES growth then form and often become quite large before autumn. There are many examples among the smaller plants, but rarely one among the trees, of indefinite annual growth; that is, the plant puts forth leaves and forms stems throughout the whole growing-season. The com- mon Locust, the ‘Honey-locust, and the Sumacs are illus- trations. Bups.— Buds are either undeveloped branches or un- developed flowers. They contain within the scales, which usually cover them, closely packed leaves; these leaves are folded and wrinkled in a number of different ways that will be defined at the end of this chapter. PosITION AND NumBer.—While the axils of the leaves and the ends of the stems are the ordinary places for the buds, there are many number, etc., that render them very interesting ‘¢ for winter study. Sometimes there are several ] to the single leaf. In the Silver Maple there are buds on each side of the true axillary one; these are flower-buds, and during the winter they are larger than the one which produces the branch. The Butternut (Fig. 14) and the Walnut have several above each other, the upper one being the largest and at quite a distance from the true axil. In these cases the uppermost is apt to grow, and then the branch is said to be extra- axillary. In the Sycamore the bud does not show while the leaf remains on the tree, as it is in the hollow of the leafstalk. In the winter the bud has a ring-like scar entirely around it, instead of the moon-shaped scar below as in most trees. The Common Locust has several buds under the leafstalk and one above it in peculiarities in regard to their exact position, °° WINTER STUDY OF TREES 3] the axil. This axillary bud may grow during the time the leaf remains on the tree, and afterward the growth of the strongest one of the others may give the tree two branches almost together. Some plants form extra buds especially when they are bruised or injured; those which have the greatest ten- dency to do so are the Willows, Poplars, and Elms. Such buds and growths are called adventitious. By cutting off the tops or pollarding such trees, a very great number of adventitious branches can be made to grow. In this way the Willow-twigs used for baskets are formed. Ad- ventitious buds form the clusters of curious thorns on the Honey-locust and the tufts of whip-like branches on the trunks and large limbs of the Elms. In trees the terminal bud and certain axillary ones, differing according to the species or variety of tree, are, during the winter, much larger than the rest. These are the ones which naturally form the new growth, and upon their arrangement the character of branching and thus the form of the tree depend. Hach species has some pe- culiarity in this regard, and thus there are differences in the branching of all trees. In opposite-leaved plants the terminal bud may be small and weak, while the two buds at its side may be strong and apt to grow. This causes a forking of the branches each year. This plan is not rare among shrubs, the Lilac being a good example. Bup-ScaLes.— The coverings of buds are exceedingly varied, and are well worthy of study and investigation. The large terminal buds of the Horse-chestnut, with their numerous scales, gummy on the outside to keep out the dampness, and hairy within to protect them from sudden changes of temperature, represent one extreme of a long line; while the small, naked, and partly buried buds of the Honey-locust or the Sumac represent the other end. The scales of many buds are merely extra parts formed for their protection, and fall immediately after the burs 32 TREES OF THE NORTHERN UNITED STATES ing of the buds; while other buds have the stipules of the leaves as bud-scales; these remain on the twigs for a time in the Ts -{ree; and drop immediately in the Magnolia. Forms or Bups.—The size of buds varies greatly, as before stated, but this difference in size is no more marked than the difference in form. There is no better way to rec- ognize a Beech at any time of the year than by its very long, slen- der, and sharp- pointed buds. The obovate and al- Y moststalked buds \, of the Alders are _¥ also very conspic- ¥ uous and pecu- liar. Inthe Balsam Poplar the buds are large, sharp- pointed, and gum. my; in the Ailan- thus they cannot be seen. All the things that might be learned from a small winter twig cannot be shown in an engraving, but the figures here given illustrate some of the facts easily determined from such specimens. The first twig (Ash) had opposite leaves and is 3 years old (the end of each year’s growth is marked by dotted lines on all the figures); the year before last it had 6 leaves on the middle portion; last year it had 8 leaves on the end portion and 12 on the side shoots of the middle portion. The buds near the Fig. 15. . WINTER STUDY OF TREES 33 end of the annual growth are strongest and are most apt to grow. The specimen illustrated was probably taken from the end of a branch of a rather young and luxuri- antly growing tree. Thus the Ash must have quite a regular growth and form a regularly outlined tree. The second twig (Sweet Gum) shows 7 years’ growth and is probably a side shoot from more or less within the tree-top. It is stunted in its growth by the want of light and room. The leaves were alternate. The third twig (Sycamore) also had alternate leaves; the pointed buds must have been under the leafstalks, as the leaf-scars show as rings around the buds. The larger branch grew three years ago. From the specimen one judges that the Sycamore is quite an irregularly formed tree. The twig had 11 leaves last year. The fourth twig (Silver Maple) shows that the plant had opposite leaves, and supernumerary buds at the sides of the true axillary ones; the true axillary buds are smaller than those at the sides. It would, in such cases, be reasonable to suppose that the supernumerary buds were floral ones, and that the plant blooms before the leaves expand. The annual growths are quite extended; two years and a part of the third make up the entire twig. If it was cut during the winter of 1891-92, it must have had leaves on the lower part in 1889 and 12 leaves on the middle portion in 1890, as well as probably 4 on the lower portion on the side shoots. Last year it had 14 leaves on the end portion, two at least on each side shoot below, making 24 in all. Folding of Leaves in the Bud. There are some peculiarities in the arrangement of leaves in the bud which can be investigated only in the early spring. The common plans among trees are—In- fleced: blade folded crosswise, thus bringing it upon the footstalk. Tulip-tree. Conduplicate ; blade folded along 3 34 TREES OF THE NORTHERN UNITED STATES the midrib, bringing the two halves together. Peach Plicate: folded several times lengthwise,like a fan. Birch. Convolute: rolled edgewise from one edge to the other. Plum. Involute: both edges rolled in toward the midrib on the upper side. Apple. Revolute: both edges rolled backward. Willow. Obdvolute: folded together, but the opposite leaves half inclosing each other. Dogwood _. in the direction of _ Caaprer VI. The Preparation of a Collection. THREE specimens are needed of each kind of tree: one, a branch showing the flowers; another, showing the fruit —one of these, and in many eases both, will show the leaves. The third specimen, cut from a large limb or trunk, shows the bark and the wood. This should be a specimen with a E surface so cut as to show the wood A the silver: grain, radial section ; with another sur- face cut in the direction of the H annual _layers, tangential section; and with a third eut across the grain, cross-sec- « tion. It should be a specimen old enough to show the change of color in the heart- wood. By taking Fig. 16. a limb or trunk 8 inches in diameter, all these points can be secured. A specimen cut as shown in the figure wiil illustrate all the desired points. Side E F G shows sap- and heart-wood in tangential section; side A BD C shows the same in radial section; end A B F 5, in cross-section ; 35 36 TREES OF THE NORTHERN UNITED STATES and B F G D shows the bark. The central pith is at I; the heart-wood extends from C to J; the sap-wood from J to D. The silver grain is well shown at the end, and the blotches formed by it on the radial section. By having the piece made smooth, and the upper part down to the center (H) varnished, the appearance of the wood in furniture or inside finish will be illustrated. The specimens should be as nearly uniform in size as possible. If a limb 8 inches in diameter be taken and a length of 6 inches be cut off, the section A B D C should pass through the line of pith; the section E F G should be parallel with this at a distance from it of two inches; and two inches from the line of pith, the section A E C should be made. The whole specimen will then be 6 inches wide and long, and 2 inches thick. The twigs containing leaves, flowers and fruit need to be pressed while drying in order that they may be kept in good form and made tough enough to be retained as specimens, The plants should be placed between a large supply of newspapers, or, better still, untarred building- felt, while drying. A weight of from 40 to 80 pounds is needed to produce the requisite pressure. The weight is placed upon a board covering the pile of plants and paper. On account of the size of many leaves and flower-clusters, these pressed specimens of trees should not be shorter than from 12 to 15 inches, and even a length of 18 inches is an advantage. The pads or newspapers should be about 12 by 18 inches. A transfer of the plants into dry pads each day for a few days will hasten the drying and increase the beauty of the specimens. The specimens of twigs can be mounted on cardboard by being partly pasted and parily secured by narrow strips of gummed cloth placed across the heavier portions. The cardboard should be uniform in size. One of the regular sizes of Bristol-board is 22 by 28 inches; this will cut into four pieces 11 by 14. Specimens not over 15 inches in length can readily be mounted on these, and for most collectors this might be THE PREPARATION OF A COLLECTION 37 avery convenient size. Another regular size is 22 by 82 inches, cutting well mto pieces 11 by 16. Specimens 15 to 18 inches long can be mounted on these. Some kinds of Evergreens, the Spruces especially, tend to shed their leaves after pressing. Such kinds can in most cases be made to form good specimens without pressing. Fasten the fresh specimens on pillars of plas- ter in boxes or frames 2 to 8 inches deep, so that they touch nothing but the column of plaster. Mix calcined plaster in water (as plasterers do), and build up a column high enough to support the branch. Place the specimen on the top of the pillar already formed, and pour over the whole some quite thin plaster till a rounded top is formed com- pletely fastening the specimen. If the leaves are not touched at all, after they are dry, they will hang on for a long time, making specimens that will show the tree char- acteristics better than pressed specimens pcssibly could. CHaprer VII. 39 FIGURES FOR BOTANICAL DESCRIPTION Fig. 28. Fig. an. Fig. 26. Fig. 30. Fig. 31. TREES OF THE NORTHERN UNITED STATES 40 Fig. 43. FIGURES FOR BOTANICAL DESCRIPTION 41 TREES OF THE NORTHERN UNITED STATES 42 FIGURES FOR BOTANICAL DESCRIPTION 43° PART IL. PLAN AND MODELS FOR TREE DESCRIPTION LL pupils should be required to write some form of composition on the trees of the region. As far as possible, these ‘compositions should be the result of per- sonal investigation. It is not what a pupil can read and redescribe in more or less his own words, but how ac- curately he can see and, from the information conveyed by his own senses, describe in his own way the things he has observed, that makes the use of such a book as this important as an educational aid. Some informa- tion in regard to trees, in a finished description, must be obtained from books, such as hardiness, geographical distribution, etc. Pupils generally should be required to include only those things which they can give from actual observation. There are four distinct forms of tree descriptions that might be recognized by the teacher and occasionally called for as work from the pupil. Ist. A bare skeleton description, wr.tten by aid of a topical outline, from the observation of a single tree and its parts. 2d. A con- nected description, conveying as many facts given in the outline as can well be brought’ into good English sen. tences. This again is the description of a single tree. 3d. A connected, readable description of a certain kind of tree, made up from the observation of many tree9 of the same species to be found in the neighborhood. 4th. The third description including information to be obtained from outside sources in regard to the origin, geographical distribution, hardiness, character of wood, habits, durability, ete. These four plans of description 44 MODELS FOR TREE DESCRIPTION 45 are more or less successive methods to be introduced as the work of a class. Pupils should be induced to carry on their own investigations as far as possible before going to printed sources for information. A good part of class work should be devoted to the first three of the methods given, but the work might finally include the fourth form of composition. The first two methods should follow each other with each of the trees studied; that is, one week let a-mere outline be written, to be followed the next week: with as clear and connected a description as the ability of the pupil will allow, and containing as much of the information given in the out- line as possible. OUTLINE FOR TREE DESCRIPTION. The tree as a whole: size, general form, trunk, branch- ing, twigs, character of bark, color of bark on trunk, branches, and fine spray. Leaves : parts, arrangement, kinds, size, thickness, form, edges, veining, color, surface, duration. Buds: position, size, form, covering, number, color. Sap and juice. Flowers: size, shape, color, parts, odor, position, time of blooming, duration. Fruit: size, kind, form, color when young and when ripe, time of ripening, substance, seeds, duration, usefr). ness. Wood (often necessarily omitted): hardness, weight, color, grain, markings, durability. Remarks: the peculiarities not brought out by the above outline. Nores on THE ForEGOING OUTLINE. The height of a tree can be readily determined by the following plan. Measure the height you can easily reach from the ground in feet and inches. Step to the trunk 46 TREES OF THE NORTHERN UNITED STATES of the tree you wish to measure and, reaching up to this height, pin a piece of white paper on the tree. Step back a distance equal to three or four times the height of the tree; hold a lead-pencil upright between the thumb and forefinger at arm’s-length. Fix it so that the end of the pencil shall be in line with the paper on the trunk; move the thumb down the pencil till it is in line with the ground at the base of the tree; move the arm and pencil upward till the thumb is in line with the paper, and note where the end of the pencil comes on the tree. Again move the pencil till the thumb is in line with the new position, and so continue the process till the top of the tree is reached. The number of the measures multiplied by the height you can reach will give quite accurately the height of the tree. The width of the tree can be determined in the same manner, the pencil, however, being held horizontally. In giving the forms of trees, it is well to accompany the description with a penciled outline. The distance from the ground at which the trunk be- gins to branch and the extent of the branching should be noted. The direction taken by the branches, as well as the regularity and the irregularity of their position, should also be observed and described. Although most twigs are cylindrical, still there are enough exceptions to make it necessary to examine them with reference to their form. Under leaves, it will be well to make drawings, both of the outline and of the veining. Crushed leaves will give the odor, and the sap can best be noticed at the bases of young leaves. The differences in sap and juice need the following words for their description: watery, milky, mucilaginous, aromatic, spicy, sweet, gummy, resinous. Pupils should not always be expected to find out much about the flowers of a tree, as they are frequently very evanescent, and usually difficult to reach. MODELS FOR TREE DESCRIPTION 47 The. fruit lasts a greater length of time and, usually dropping spontaneously, gives a much better chance for investigation. Specimens of most of the common woods may be ob- tained from cabinet-makers and carpenters. In cases where these specimens are at hand, description of the wood should be required. If the school has such speci- mens as are described in Chapter VI., Part I., the wood in all its peculiarities can be described. Examezz8 OF TREE DESCRIPTION. Taxodium distichum (Bald Cypress). (Atterbury’s Meadow.) No. 1. Tree eighty-four feet tall, thirty feet wide near base ovate, conical, pointed; trunk seven feet in circumfer ence near base and ridged lengthwise, but only four feet at the height of six feet from the ground, where it becomes round or nearly so, then gradually taper- ing to the top; branches small, very numerous, beginning six feet from the ground, sloping upward from the trunk at an angle of nearly forty-five degrees ; twigs very slender, numerous, pendu- lous, two, three or even more growing to- gether from supernumerary buds around the old scars; bark brownish, quite rough, thick and soft on the trunk, smoother on the branches, greenish on 28% the young spray. Leaves about sessile, without stipules, alternate, crowded, two-ranked, thin, linear, entire, par. allel-veined. with midrib, dark green, smooth, deciduous 48 TREES OF THE NORTHERN UNITED STATES Buds show in the axils of only a few of the leaves, and are very small; but there are several supernumerary buds around many of the clusters of the shoots of the year. Sap clear and slightly sticky with resin. Flowers looked for, but not seen; must have been small, or have bloomed before my examination in the spring. Fruit one inch in diameter, cone globular, brown in the autumn; did not notice it before; fifteen six-sided scales, two seeds under each, still hanging on, though the leaves have dropped; only to pro- duce seeds, I think. The wood I do not know about. Remarks. Around the base, at some distance from the trunk, there are four peculiar knobs, seemingly coming from the roots, one being nearly a foot high and nine inches through. No. 2. The Bald Cypress standing near a small ditch in Atter- bury’s meadow is a very beautiful, tall, conical tree, over 80 feet high, with an excurrent trank which j is very large and ridged near the ground. It tapers rapidly upward, so that the circumference is only about half as great at the height of 6 feet, where the branches begin. The branches are very numerous and, considering the size of the trunk, very small; the largest of them being only about 2 inches through. They all slope upward rapidly, but the tip and fine spray show a tendency to droop; the fine thread-like branchlets, bearing the leaves of the year, are almost all pendulous. The bark is very rough, thick and soft, as I found in pinning on the bit of paper to measure the height of the tree, when I could easily press the pin in to its head. MODELS FOR TREE DESCRIPTION 49 The leaves are very small and delicate, and as they ex- tend out in two ranks from the thread-like twigs, look much like fine ferns. The small linear leaves and the spray drop off together in the autumn, asI can find much of last year’s foliage on the ground still fastened to the twigs. I could not see any flowers, though I looked from early in the spring till the middle of the summer; then I saw afew of the globular green cones, almost an inch in diameter, showing that it had bloomed. Next spring I shall begin to look for the blossoms before the leaves come out. On the ground, about 6 feet from the tree, there are four very strange knobs which I did not notice till I stumbled over one of them. They seem to grow from the roots, and are quite soft and reddish in color. No. 3. I have found twenty-two Bald Cypresses in Trenton; they are all beautiful conical trees, and seem to grow well in almost any soil, as I have found some in very wet places and some in dry, sandy soil. They look from their position as though they had been planted out, and as I have found none in the woods around the town, they are probably not native in this region. They are from 50 to nearly 100 feet tall. I found one 96 feet high. They are all of a very symmetrical, conical form,and pointed at the top; in no case has the trunk divided into branches, and on the old trees the trunk enlarges curiously near the ground, the lower portion being very rough with ridges. The bark is very thick and rough, and is so soft that a pin can readily be pushed through it to the wood. The branches are very numerous and small, and are not regu- larly arranged in whorls like most of the narrow-leaved trees. These branches all slope upward from the trunk, the ends having a tendency to bend downward and make delicate drooping spray, with very small, linear, entire 50 TREES OF THE NORTHERN UNITED STATES leaves only 4 inch long. Four of the largest trees show fruit, and each of these has only about a half-dozen of the globular cones. Only a few of the trees—those in the wettest places—have the knobs on the ground near the base. No. 4. The Bald Cypress (Taxodium distichum) is a common tree, a native of the Gulf States, growing very abundantly ‘in the wettest swamps of that region. The northern limit of the tree in its wild state is said to be central Delaware and southern Ilinois, but it can be successfully cultivated in the region around Boston. There are several named varieties, one with the leaves but slightly spread- ing from the spray, and the whole of the branches show- ing a decided weeping tendency, so that it is called the Weeping Cypress. The knobs from the roots, called Cy- press-knees, grow very abundantly around all the trees in the southern swamps. These grow to the height of from 2 to 4 feet, and are very thick, sometimes as much as 5 feet. They are hollow, and are occasionally used for bee- hives. It is said to be a broad, flat-topped tree, spreading its top over other trees. This seems very strange, as none of those in Trenton, N. J., show such a tendency, but are quite spire-shaped. The wood is light, soft, straight- grained, and is said to be excellent for shingles and for other purposes. It generally has a dark reddish or brownish hue. It is a large tree, growing to the height of 140 feet. The trunk is sometimes 12 feet through near the ground. The flowers of the tree are in small catkins, blooming before the leaves expand in the early spring; in February, in South Carolina. PART III. KEY, CLASSIFICATION AND DESCRIPTION OF THE SPECIES. Method of Using the Key. IRST read all the statements following the stars (*) at the beginning of the Key; decide which one of the statements best suits the specimen you have. At the end of the chosen one there is a single or double letter in parenthesis. Somewhere below, this letter is used two or more times. Read carefully all the statements follow- ing this letter; at the end of the one which most nearly states the facts about your specimen, you will again be directed by a letter to another part of the Key. Continue this process till, instead of a letter, there is‘a number and name. The name is that of the genus, and forms the first part of the scientific name of the plant. Turn to the de- scriptive part of the book, where this number, in regular order, is found. Here descriptions of the species of the genus are given. If there are many species, another Key will lead to the species. While the illustrations are in- tended to represent characteristic specimens, too much dependence must not be placed upon them; the leaves even of the same plant vary considerably, and the differ- ent varieties, especially of a cultivated plant, vary widely. Read the whole description before deciding. The fractions beside the figures indicate the scale of the drawing as compared with the natural size of the part: 1 indicates natural size; 2, that the drawing is twice the length of the object; 4, is one fourth the length, etc. In the description of leaves the dimensions given refer to the blade. 61 52 TREES OF THE NORTHERN UNITED STATES KEY TO THE GENERA OF TREES. * Leaves narrow linear, needle, scale or awl shaped, usually but not always evergreen. (GG.) page 60. * Leaves broad, flat, usually deciduous; occasionally evergreen, rarely over 5 times as long as wide. (aa.) aa. Leaves alternate (see p. 18, Caution), simple. (bb.) aa. Leaves alternate, compound. (m.) page 57- aa. Leaves opposite or whorled on the stem. (u.) page 58. bb. Leaves with a midrib, netted-veined. (cc.) bb. Leaves without a midrib, parallel-veined (appearing fan-like)... CREM a Nas Rae San aase Mose eee neo estes 109. Salisburia. ec. With radiating ribs, and including those which have the lower ribs longer and more branching than those above them. (K.) ec. With distinct and definite feather-veining. (dd. ) dd. Margin entire, or so nearly so as to appear entire, sometimes slightly angulated but not lobed. (V.) page 55. dd. Once or twice serrate or crenate or wavy-edged, but not lobed. (ee. ) dd. Distinctly lobed. (S.) (If the notches are over 10 on a side, look under ee.) ee, Straight-veined. (L.) ee. Not distinctly and evenly straight-veined. (ff.) ff. Leaves evergreen. (A.) ff. Leaves deciduous. (B.) A. With either revolute or spiny-tipped margins...... ..18. Tex. A. With minutely serrate margins and wedge-shaped bases; flow- ers white, 3-4 inches wide. No. 1in............ 8. Gordonia. A. With entire or minutely serrate margins and rounded bases ; flowers inconspicuous. No. 3in.............0. 20. Rhamnus. B. Leaves broadened and coarsely notched near the tip ; whole plant whitened with scurf............ cece ewer eee ee 49. Baccharis. B. Leaves sour; peach-like in shape.............. 50. Oxydendron. B. Leaf length usually 3 or more times the width; finely serrated (or entire) ; buds covered by but one scale; large stipules often present On SOME tWIGS....... 0 cece ee eee teen 91. Salix. B. Plants thorny. (C.) B. Not included in the above. (H.) C. Lowest side veins much the longest ; leaves sometimes opposite. NOL DNs cits ep sap ramaa igi way tawaloaa eee ets 20. Rhamnus KEY TO THE GENERA OF TREES 53 C. Not asabove. (D.) D. Leaves once serrate; base rounded; fruit a drupe (as plum, Cherry!) tsnauwhigevy on cei gwsees eda as ees aaa. 36. Prunus. Leaves serrate to irregularly lobed; all of the unarmed northern forms which are not lobed have a decidedly wedge-shaped base or are hairy below ; fruit berry-like, ending in a persistent calyx. . schenseeeg saevitidy once eubaae ed ey eee see ed 38. Orateegus, E. Leaves with decidedly tonic taste, or petiole with one or more glands near the blade; never woolly below ; fruit a drupe..... oh cpSashasetiniecmPianee saan led TDA AAMAS Rane a DEA Empey 36. Prunus. E. Leaves woolly below ; fruit a pome. Apple and quince in.... Spa AehiiedeRee nae ee sy Laas nr MRET gs welee Me 37. Pyrus BE. Notas above. (F.) F. Leaves rounded to elliptical, shining above, abruptly acute at the Uipiy. “PEA Tanke adainas SG Pere Ee caendetlales 37, Pyrus. F. Leaves more often entire than serrate; rare north of Virginia. NOS 2 Mss \chaucisiadsiee Matsa eee lng ae gbess Seaeene 6 20. Rhaminus. F. Leaves deltoid, very acuminate. No. ]in........... 83. Betula- F. Leaves white beneath ; flowers 3-4 inches wide. No, 2 in....... i djantl Sra tub daemon eee MOTa ES ERE A SANGRE S E.OaeE 8. Gordonia. Leaves scurfy or with stellate hairs. .56. Styrax or 57. Pterostyraz. Leaves not included in the above. (G.) G. Leaves decidedly widest near the tip. (R.) G. Leaves not as above. (H.) H. Leaves smooth ; flowers white, rose, or greenish. (I.) H. Leaves pubescent below; some species smooth when mature ; flowers white. (J.) I. Glaucous Belen finely serrate ; flowers small, white........ eked ss Bett OER RENN Giga alOes inte k tacks Grate Bie te eth caters 53. Clethra. I. Leaves less finely serrate, one species sometimes 38-lobed ; flowers large, rose-color. Crab apples in.......... 387. Pyrus. I. Finely serrate ; flowers inconspicuous; berries red....18. Ilex. J. Flowers large, 4-lobed, drooping ; fruit 2-4 winged............ dota ian eh Ciahahedn Sas boa rite, BYR Wag ante A/G. os RiaB ease RNS LSe Rh kde SAL 58. Halesia. J. Flowers of 5 or more distinct petals ; petals broad; fruit few- seeded capsule...... 0... cece eee eet eer e neers 7. Stuartia. J. Flowers of 5 or more distinct petals; petals usually narrow and long ; fruit sweet, apple-like pome............ 39. Amelanchier. Usually thorny ; shrubs rather than trees ; fruit rounded berries ending in persistent calyx lobes..............4+ 38. Crategus. Not thorny; leaves deltoid, very acuminate; bark white in mature-trees: Nos 1 mes iv soy ese unasiensais aw atin ae 83. Betula. Not thorny ; leaf lobed ; end of leaf as though cut off......... Tie ehakeeibbas svae otond Auden 3.5 SNe eee ceseseneeees 2. Liriodendron. Not as above, (f.) page 56. rh ROK OR A 54 TREES OF THE NORTHERN UNITED STATES L. L. N. N Leaves oblique at base. (M.) Leaves not oblique at base. (N.) M. Margin wavy ; spreading shrub.............. 40. Hamamelis M. Margin serrate, leaves usually rough above; trees .......... GEae HATH Wiley auch Pot eGe CNG a ees aetare len 74. Ulmus. Margin wavy or wavy-lobed ......... eee eee ee eee 88. Quercus. . Margin coarsely serrate, each main vein ending in a tooth, and no teeth between these veins (European beech entire or angulated to pinnatifid). (0.) ‘ N. Margin serrate, but not as above. (P.) O. Buds long and slender ; teeth not awned........... 90. Fagus. O. Buds not as above; teeth more or less awned and incurved.... MANA MAINES TEENA ES RATRTAS Koywueaneets 89. Castanea. P. Bark scaling off in plates, as in sycamore.......... 75. Planera. P. Bark close, smooth, muscular rather than furrowed; fruits in leafy-bracted clusters........ erase 86. Ostrya or 87. Carpinus. P. Bark horizontally marked, and peeling in horizontal strips rough in Nos 6)cs seagss waneawe dies gesue eet v eis ee eaesan 83. Betula. P. Notas above. (Q.) Q. Woody cones always present...........e0..0 02 2 84. Alnus. QO) Twigs Ralry. sia oseswiwlsia dace en eeee wenn oe 85. Corylus. Q. Not as above.............. Pdeltiiereter Spacdiaiaidin $G0trece 53. Clethra. R. Flowers white, 2 inches wide, solitary. No. 2in..... 7. Stuartia. R. Flowers white, small, in racemes ; leaf base entire and decidedly wedge-shaped. No. 2in...... ccc cece cect eee eens 53. Clethra. S. Plant more or less thorny; shrub or small tree; fruit round berries ending in persistent calyx-lobes......... 38. Crategus. T. T. aq oe a S. Plant not thorny. (T.) Leaf deeply pinnatifid, usually with the basal lobes completely separated ; cultivated... 0... cece eee ee aeons wees Ol. Pyrus. End of leaf as though cut off or notched; sides with one large lobe ; margin entire; large tree.............+..2. Liriodendron. Lower leaves three-lobed, heart-shaped at base, upper merely ovate, margin entire; small tree or shrub............. eWaeeetele Sapien MvahAwale beets ed cgi y ae eat 66. Clerodendron. . Some leaves without lobes, all with tapering base, aromatic.... AS A apd iase te ver eae evans into aasene ca Gree ERAN. Sli 69. Sassafras. Not as above ; leaves usually many-lobed. (U.) Leaves thin; bark of trunk peeling off in thin horizontal BUTI PS isha eines, areal y Paletea eee teeeeeseee. 83, Betula. Leaves thin; leaf-buds long, slender, sharp-pointed ; bark smooth, not peeling; cultivated................00. 90. Fagus. . Leaves thickish; bark roughish; fruit an oval woody cone, remaining on through the year...............0.08- 84. Alnus. Leaves thick ; fruit an acorn......... sae wheitins 88. Quercus. KEY TO THE GENERA OF TREES 55 V. Leaves evergreen, small, 2-3 in, long, thick, with revolute mar- < gins, Fruit anacotns os aad eave vege ecdeeesk 88. Quercus. Hruitited ‘berries: + sediwaenerdawesies mces soeeicac aes 18. Ilex. . Leaves evergreen, oval to lance-oval, usually large; small trees, almost shrubs. (d.) page 56. V. Leaves deciduous (some are evergreen in Southern States). (W.) MM NM OM N NNN W. Plant more or less spiny. (c.) W. Plant not at all spiny. (X.) . Leaf-blade thin, ae pointed, with curved parallel veins or FDS) oye hi yenaswe Dearest reac er cdaoMaenee waded 45. Cornus. . Leaf-blade thin, circular or broadly oval in outline, with blunt, almost rounded apex; veins not regularly parallel ..27. Rhus. . Leaf quite elongated, 5 or more times as long as wide. (b.) . Leaves with nono of the above peculiarities. (Y.) Y. Deciduous bud-seales (stipules), leaving a sear or mark com- pletely around the stem at the base of the leaves. 1. Magnolia. Y. Leaves covered on one or both sides with silvery scales .... shisetltid te aE acs ECM RI bay Be esatlertide WAAR Sins ina at 8 Are cuamed 71. Eleagnus. Y. No such ring around the stem, or silvery scales on the leaves. (Z.) . Leaves distinctly straight-veined, thin............. 90. Fagus. . Leaves thick, obtuse; fruit an acorn .. ......... 88. Quercus. . Leaves 6 in. or more long; crushed leaves with a rank, fetid GAOT 6 nscidgata teh Deee ar weaiekegenate: RESSKas 5. Asinina. . Leaves 3-5 in. long; twigs and leaves very spicy; tree or SHIUDs ss ssees0e-daad auaemeeces 69. Sassafras 70. Lindera. . Leaves about 2 in. long, oval, on twigs which have ridges extend- ing down from the sides of the leafstalk; small tree, almost a shrub, with large beautiful flowers ......... 43. Lagerstremia. . Leaves not as above. (a.) a. Fruit a large (14-114 in.) rounded pulpy berry with a heavy calyx at the base... i.cessaceciadaesnssecnoin 55. Diospyros. a. Fruit small (1% in.), fleshy, drupe-like, with a striate stone; limbs branching horizontally, often descending ...46. Nyssa. a. Fruit a black, juicy berry (44-44 in.), with about 3 seeds Higlas Madah_ ohn lestsey shaven tgoiednaen tar coahog wloaeltpinatal se - ....20. Rhamnus. a. Fruit an ovoid dry drupe (14 in.); leaves sweet-tasting praca, “1 aahaunteertiaiy a, Saas bbisnataccry ah ariweitvehsicedesaMce . 59. Symplocos. a. Fruit an apple-like pome (Quinee)................ 37. Pyrus. pb. Wood soft; both kinds of flowers in catkins in spring; with either stipules or stipular sears..................464. 91. Salix. b.. Wood hard; leaves thick; fruit an acorn.......... 88. Quercus. c. Fruit a 2-4-seeded small berry; juice not milky...... .. enone, enn accel ae or 20. Rhamnus. 56 TREES OF THE NORTHERN UNITED STATES c. Fruit large, orange-like in size and color when ripe; juice MIUKY sicarcencse eas anes ee Per rrr 77. Maclura. c. Fruit small, black when ripe, cherry-like; juice milky ...... SpainonsimeanintyR anit Rec tN Stak Gel lab aaa a AO Se ed 54. Bumelia. d, Aromatic; berries dark blue on red stalks.......... 68. Persea. d. Not aromatic; leaves nearly 1 ft. long; flowers large and soli- LEY is cd stecencavlayartinn Nada one Sanat BRO ate literally NO wiv «1. Magnolia. d. Not aromatic; leaves 1-4 in. long; flowers very small; fruit small dark-colored berries, with 2-4 seeds....... 20. Rhamnus. d. Not aromatic; flowers large, in showy ciusters. (e.) e. Leaves 5 in. or more long................ .52. Rhododendron. e. Leaves less than 4 in. long...... Satie sub laltersstua wiayartes 51. Kalmia. f. Leaves decidedly aromatic, usually somewhat irregularly lobed, margin entire, base tapering..................5. 69. Sassafras. f, Leaves usually deltoid, sometimes heart-shaped with serrate margin and gummy buds, rarely palmately lobed. All have either the petiole flattened sidewise, the leaf-blade densely silvery-white beneath, or gummy aromatic buds... .92. Populus. f. Leaves broadly heart-shaped; margin entire; small tree with abundance of red flowers in early spring; fruit a pea-like pod S4SsneGeusseoosey Wienats BPR EE Fey os RESTOR A eves Bos, WOONCIRS f. Leaves not as above given. (g.) g. Leaves broadly heart-shaped, with a serrate margin and a petiole about as long as the blade, sometimes longer; base of leaf not oblique..................0000- sapastte 4. Idesia. g. Leaves broadly heart-shaped, those on the suckers much lobed; base not oblique; margin serrate; juice milky; bark very tough. (1.) g. Leaves broadly heart-shaped, with an oblique base; margin regularly serrate ; juice not milky..... Seee eRe es ll. Tilia. g. Leaves slightly if at all heart-shaped at base, usually some- what oblique, with neither milky juice nor lobes. (j.) g. Leaves decidedly and quite regularly lobed. (h.) h. Leaves with 3-5 large lobes, the margin entire or slightly an- GUated i iat carey gnkow, Nea geieseeyarecee es 10. Sterculia. h. Leaves star-shaped, with 6- -9 pointed, serrate lobes. (i.) h, Leaves large, irregularly margined; leaf-stem covering the bud $ laree trees oo ccp eee vee sein geraences 80. Platanus. h, Plant quite thorny; fruit berry-like, ending in a conspicuous spreading calyx; small trees or shrubs with apple-like blos- BONS scuocmerinsineense Panes ogee Mieke eA vapaintaS 38. Crategus. h, Leaves with uw tapering base; seaaill tree, almost a shrub, with large Hollyhock-like ower ; plant not thorny ....... sarge eS deietace bene bbe eeet ceeeeererssecenetss@iesss D Hibisous KEY TO THE GENERA OF TREES of i. Large tree, with fruit 1 in. in diameter, dry, rough, hanging O18 1ONg, SlOM i esceweiicmadees ae abe. Sema 41. Liquidambar. i, Small tree with few branches and the trunk usually quite prickly ; fruit berry-like in large clusters......... 44. Aralia. j. Fruit small berries, with 3 flattened seeds, in clusters in axils of leaves, which are decidedly 3-ribbed from base....21. Hovenia. j. Fruit small drupes, with 1 seed, either solitary or in pairs in the axils of the leaves. (k.) k. Plant without prickles; leaves decidedly oblique at base.... onlay daegai tats Magu pega ek Cah Dap ant can Memnaaceaia a hes Bach 76. Celtis. k. Plant with prickles; leaves narrow, decidedly 3-ribbed, and 2-ranked on green twigs...........--..seeeeee. 22. Zizyphus. 1, Fruit not very edible; leaves rough above, very hairy below, on some of the twigs opposite ................ .79. Broussonetia. 1, Fruit edible; leaves not very hairy, never opposite. .78. Morus. m. Leaves of 3 entire-edged leaflets; fruit a pea-like pod. ... (AGES eeahee te wepmach as eG ke ctw otaneet te 28. Laburnum. m. Leaves of 5 leaflets; thorny .............0-. 000s 44. Aralia. m. Leaves of 3 quite regularly serrate, transparent-cotted Leahets: sie canaas ce ee Wiewn tana denn ata 13. Ptelea. m. Leaves once or twice pinnate; the leaflets entire. (s.) m. Leaves once or twice pinnate ; the leaflets with margins more or less serrate or notched. (n.) n. Leaves irregularly once to twice, in one case three times, pin- nate. (r.) n. Leaves regularly once pinnate. (0.) o. Leaves less than 1 ft. long, on a small, generally quite prickly plant; fruit very small pods (4 in. long)..12. Xanthoxylum. o. Leaves less than 1 ft. long; leaflets 3 in. or less long; fruit bright-colored, berry-like pomes in clusters, persistent through the autumn; plant not thorny; branches not heavy-tipped sie inert ARGO MAROTAG (ER RA BEERS MMC A MONEAEG Fee 7B EN 37. Pyrus. o. Leaves usually larger on the small tree or almost a shrub; juice in most cases milky; branches heavy-tipped 27. Rhus. o. Leaves 1-2 ft. long; leaflets 3 in. or more long; fruit a bony nut with green fleshy coat; large trees. (q.) g. Leaves very large, 2 ft. or more long on the rapid-growing branches; branches heavy-tipped; odor of bruised leaves quite strong; leaflets 15 or more in number; large trees; juice not milky. (p.) p. Leaflets with 1-3 glandular notches at the base.......... SO PMR eeseeeg see PeMEeRee. gee Seder gk 17. Ailanthus. p. Leaflets entire at base, but very slightly serrate near the tip Soh ehh OIs $4 pd Se Te Ves ee BaEaeNe ees Fee -16. Cedrela. 58 Yr. r. Yr. t. TREES OF THE NORTHERN UNITED STATES q. Coat of fruit more or less dehiscent into 4 valves; nut smoothish ; leaflets, except in one species, not over 11 in number, usually 5-7; pith not in layers .......... 82. Carya.. q. Coat of fruit not regularly dehiscent; nut, in the wild species, rough-coated; leaflets, except in a cultivated species, over 11 in number ; pith in layers in old wood........... 81. Juglans, Leaves quite regularly twice odd-pinnate; leaflets about 1 in. long; juice not milky; fruit rounded berries in large clusters ; plant not prickly; branchlets not heavy-tipped ..... 15. Melia. Leaves once to twice irregularly odd-pinnate; the leaflets very irregularly and coarsely toothed; a small, round-headed tree with bladdery pods........ 6... see eee eeee 24. Kelreuteria. Leaves irregularly about twice odd-pinnate ; the leaflets lanceo- late; quite a low plant with few heavy-tipped branches; plant without prickles 0.00 1.6.0 cece cee eee eee eee tees 27. Rhus. . Leaves 2 (sometimes 3) times odd-pinnate; tree-stem with prickles; small tree or shrub, with few branches......... utah alee ue a haha Smee tera linana cle | fepslagrepa's heheh: Shy sl 44, Aralia. . Leaves once to twice abruptly pinnate; large tree with slender- tipped branches, usually very thorny .......... 34, Gleditschia. s, Leaves very large (2 ft. or more long), about twice abruptly pinnate; leaflets broad and often 2 in. long; branches blunt; NGEAHOMMS . .ca2useiekiiw, segment quae 33. Gymnocladus. s. Leaves and leaflets much smaller, leaves quite irregularly once or twice abruptly pinnate; branches slender-tipped ; large tree, usually very thorny .............. 34. Gleditschia. s. Leaves twice abruptly pinnate; leaflets over 400 in number, with midrib near the upper edge......... ...... 35. Albizzia. s. Leaves regularly once pinnate, not over 2 ft. long. (t.) Leaves abruptly pinnate, not over 5 in. long; leaflets 8-12, small, mucronate-pointed.............6. seaeeee 29. Caragana. . Leaves odd-pinnate; shrub or small tree, with few, heavy-tipped branches ; no spines or prickles... .... ............27. Rhus. . Leaves odd-pinnate ; leaflets large (3-5 in. long), not usually over 11 in number.............. 30. Cladrastis, or 81, Juglans. . Leaves odd-pinnate ; leaflets less than 3 in. long, frequently 11-21 in number; often with spines at the bases of the leaves inthe place of stipules .. . 12. Xanthoxylum or 31. Robinia. u. Leaves palmately compound. (CC.) u. Leaves pinnately compound. (BB.) u. Leaves simple, evergreen, sessile, in whorls around the stem, which they completely cover.............. (984, Araucaria.) u. Leaves simple, opposite, evergreen, entire, over 2 in. long etd AS Os iaue sectecnenerncievavenners os es OL. Osmanthus. KEY TO THE GENERA OF TREES 59 u. Leaves simple, opposite, evergreen, entire, under 1 in, long u. u. idedel Seb age Re aG Sh ee HN SSeS KEES E RETR SE oR eS ..73. Buxus. Leaves simple, evergreen, crenate, 2 in. long..19. Huonymus. Leaves simple, deciduous. (v.) v. Branches ending in thorns; small trees, or shrubs. (AA.) v. Plants not thorny. (w.) Ww. w. w. Leaves palmately lobed (one variety, rarely cultivated, lacks lobes, but is heart-shaped with a serrate margin), the lobes over 3 in number, or with notches or serrations; fruit dry, WANSEDS sco diduincwpeamatievedt Sa (Raammonzestes & 25. Acer. . Lower leaves palmately 3-lobed, and heart-shaped at base, upper ones ovate, all with entire margin; fruit with juicy pulp covering the 4 seeds....... ......... 66. Clerodendron. . Leaves palmately lobed; fruit small, one-seeded, berry-like drupes in large clusters, with flattened stones, or large rounded clusters of flowers without stamens or pistils; shrubs rather than trees..................00. 47. Viburnum. Leaves heart-shaped, entire or slightly angulated (may be crenated in Cercidiphyllum), not lobed. ~(DD.) Leaves irregularly serrate, somewhat straight-veined ; fruit single-winged; large cultivated tree .......... 60. Fraxinus. Leaves neither heart-shaped nor lobed; small trees, almost shrubs. (x.) x. Leaves entire. (z.) x. Leaves serrate or dentate, ovate or oval. (y.) y- y- Fruit rounded drupes in large clusters, with single flattened SCORES! oc sarsrwdied, one hed ee ee 47. Viburnum. Fruit lobed pods, which burst open in the autumn; branch- lets somewhat 4-sided .. ...............00.. 19, Luonymus. z. Leaves small, lanceolate; flowers and fruit large and beautiful Ld aikG He. ELS ERLE Oe, MAC ODERE TA GO UD eee .42.-Punica. z. Leaves broad, thin, with curved parallel veins or ribs. 45. Cornus. z. Leaves large, broad, oval, without either curved or straight par- allel ribs .......... uid senaeen 62. Syringa or 63. Chionanthus, AA. Leaves entire and covered on both sides with silvery, pel- GALE SCALES jacey eae ceaan cans Pecolo ay eRe 72. Shepherdia, AA. Leaves ovate, small, minutely serrate....... 20. Rhamnus. BB. Leaves large, 18 in. or more long; leaflets 11 or more, very finely serrated or entire ................. 14. Phellodendron. BB. Leaves smaller ; leaflets entire or quite evenly toothed, usu- ally over 5 in number...............0000-0005 60. Fraxinus BB. Leaflets coarsely and quite irregularly toothed, 3-5 (rarely 7 in numbers... 0c.ceee ee er ee 26. Negundo. CC. Leaficts slender-lanceolate ; shrub or small tree with aro- matic leaves and somewhat 4-sided branches.....67. Vitea. 60 TREES OF THE NORTHERN UNITED STATES CC. Leaflets broader and serrate; usually large trees, 23. Zisculus. DD. Leaves with radiating ribs. (FF.) t DD. Leaves with feather-veining. (EE.) EE. Leaves 2-6 in. long; flowers small, in large, dense, ter- minal clusters: .4sci64 gecesi he Mend aa eas ea se 62. Syringa. EE. Leaves 1-4 in. long; flowers in pairs.. ..... 48. Lonicera. FF. Leaves large, 6 in. or more long; two almost hidden buds, one above the other, in the axils of the leaves on the rapid- growing branches; flowers large, purple, blooming in early spring; fruit rounded pods ...... ........... 64. Paulownia. FF, Leaves large, 6 in. or more long; flowers large, white, bloom- ' ing in June; fruit long pods.................... 65. Catalpa. FF. Leaves 2-4 in. long, with red stems ...... 3. Cercidiphyllum. GG. Leaves scattered singly over the stem, not in bundles or clusters. (JJ.) GG. Leaves in large or small clusters. (HH.) HH. Clusters in whorls of many leaves around the stem like an UMbC a. .cvknccccvuncnes sa raceraneewess 100. Sciadopitys. HH. Leaves clustered in bundles of 2-6 .. .......... 93. Pinus. HH. Leaves clustered in bundles of over 8. (II.) II. Leaves deciduous, soft ........ 0... cece eee 97. Larix. II. Leaves evergreen, rigid ....... ......-..e eee 98. Cedrus. JJ. Leaves hardly evergreen; spray quite slender. (ZZ.) JJ. Leaves fully evergreen. (KK.) KK. Leaves awl or scale shaped, and mainly appressed to the stem. (WW.) KK. Leaves linear or needle shaped, and decidedly spreading from the stem, though sometimes with a decurrent base. (LL. ) LL. Leaves narrowed to a distinct though short stem. (RR.) LL. Leaves sessile; if narrowed, not so abruptly as to form a petiole. (MM.) MM. Leaves opposite or whorled on the stem. (PP.) MM. Leaves rather spirally arranged around the stem, not just opposite. (NN.) NN. Leaves linear to lanceolate, fiattened, spreading quite squarely from the stem. (00.) NN. Leaves not flattened but 4-sided, curved, gradually enlarging from the tips to the bases, which are decurrent, and on the young twigs completely cover the stem ; cones rounded, their scales not lapping............. i Winelew Gre 105. Cryptomeria. OO. Leaves about linear in form, of nearly the same width throughout, and usually fastened to the cylindrical stem bya distinct disk-like base; cones erect; scales lapping. 96, Abies. KEY TO THE GENERA OF TREES 61 OO. Leaves about 2 in. long and gradually widening from the acute tips to the broad (% in.) bases, which are decurrent ON, THE Ste canine as aweaeea Rann 99. Cunninghamia. OO. Leaves 14-1 in. long, sharp-pointed, very flat, two-ranked, somewhat lanceolate in form; base narrowed almost to a POLO C55 wel sidmadictsnordadoadin an edsam Se 102. Sequoia. PP. Leaves not decurrent, usually in whorls of three around the stem, sometimes opposite, acute-pointed; fruit small (% in.), rounded, dark-colored berries ............... 106. Juniperus. PP. Leaves decurrent on the stem, less than 44 in. long. (QQ.) QQ. Fruit small, globular cones; the scales not lapping....... Sia SEAS GED EA teamed re FERS SEE 104. Chamecyparis. QQ. Fruit small, elongated cones of few, lapping scales....... fasede. opgaaghatitewsteawiyaacee ad seecangs 103. Thuya. RR. Leaves usually but little flattened, but jointed to a short, brown petiole which is attached to'a somewhat grooved twig; cones pendent, of lapping scales........ .. 94. Picea. RR. Leaves decidedly flattened, not jointed, but narrowed to a petiole which is usually green or greenish in color. (SS.) SS. Leaves rounded or obtuse at the tip, distinctly two-ranked, usually less than 1 in. long; cones oval, 1 in. or less long, OL lapping SCA1ES. i wieceiasecav ers ereeaedcneaes 95. Tsuga. SS. Leaves acute at the tip; fruit (found only on wu portion of the plants, as the flowers are dicecious) drupe-like, with a single nut-like seed. (TT.) TT. Leaves not two-ranked, over 2 in. long..... 108. Podocarpus. TT. Leaves quite regularly two-ranked. (UU.) UU. Leaves marked by two longitudinal lines; bruised or burned leaves with a very disagreeable odor............. Bib weal vegan tank gussets eles Tues s aaeAEA +++. (1078, Torreya.) UU. Leaves with the midrib forming a distinct ridge, odor not disagreeable. (WV.) VV. Leaves usually less than an inch long........... 107. Taxus. VV. Leaves usually more than an inch long.................. Sach pitas Shear SE Rtas SoBe Shae & aes ahaa ueedoce tats (107. Cephalotaxus.) WW. Spray decidedly two-ranked, fan-like. (YY.) WW. Spray branching in an irregular way, not two-ranked. (XX.) XX. Fruit a purplish berry; bark shreddy ....... 106. Juniperus. XX. Fruit a cone of thick, pointed, not lapping scales.......... Set opie ES aipthoardyar.shtneatd Gagan new eae echataaaer aed Situs 102. Sequoia. YY. Cones elongated, of lapping seales............ 103. Thuya. YY. Cones globular, of peltate, valvate scales ................ sp aAlataht B04 84 4-6:¢ BY eae dinateaigeavees 104. Chamecyparis. 62 TREES OF THE NORTHERN UNITED STATES ZZ, Leaves very broad at base, half clasping the stem and rapidly narrowed to an acute tip; hardly at all spreading from the thread-like twigs; flowers pinkish, in spike-like clusters. ... hapegined Magia side Ba Rik 4 a/8 & pees Bes se ysis imanbeoaaiwn 6. Tamarix. ZZ. Leaves more elongated, quite even in width, not clasping the SLOMs Secoewat As a4 seeds Sea yeh oe -101. Taxodium. CLASS IL ANGIOSPERMZ. Plants with a pistil consisting of a closed ovary, which contains the ovules and forms the fruit. OrvEeR I. MAGNOLIACEA. (Maenorta Famiy.) Trees or shrubs, mainly of tropical regions, including, in our section, the three following genera: Genus 1. MAGNOLIA. Trees and tall shrubs with alternate, thick, smooth, en- tire leaves with deciduous stipules which form the bud- seales, and are attached entirely around the stem, leaving a ridge, as in Liriodendron. Flowers very large (3 to 10 in. in diameter), usually white, solitary. Fruit a large cone from which the seeds, drupe-like, usually red, hang out on long threads during the autumn. * Blooming with or before the opening of the leaves. (A.) A. Flowers entirely white............. 00... ccc eee eee 9, 10. A. Flowers dark purple.......... 06 eee eee eee ee 11. A. Flowers mixed purple and white. PripE or InpIA.) Leaves very large, doubly pinnate, with many obliquely lance-ovate, acuminate, smooth, serrate leaflets. Flowers small, lilac-colored, de- liciously fragrant, in large axillary clus- ters. Fruit globular, as large as cherries, yellow when ripe in autumn; hanging on through the winter. A rather small (20 to 40 ft. high), rapidly growing, round- headed, popular shade-tree in the south, and hardy as far north as Virginia, In- M. Azédarach. troduced from Persia. 76 TREES OF THE NORTHERN UNITED STATES Genus 16. CEDRELA. Leaves large, alternate, deciduous, odd-pinnate. Flow. ers with separate petals, fragrant, white, in large clusters. Fruit 5-celled dehiscent pods,with many pendulous, winged seeds. Cedréla Sinénsis. (CHINESE CEDRE- LA.) Leaves large, odd-pinnate, alter- nate, appearing much like those of the Ailanthus, but with slight serrations near the tips of the leaflets, and noglandsnear the base. Bruised leaves with a strong - odor; footstalk and stout-tipped branches with glands. Large tree, seemingly hardy in New Jersey, but dies to the ground in winter in Massachusetts. Recently in- troduced from China. C. Sinénsis. ORDER XI. SIMARUBACEZE. (Quassia Famity.) Kastern trees and shrubs, here represented by a single tree: Genus 17. AILANTHUS. Large trees to shrubs, with alternate, odd-pinnate leaves. Flowers small, greenish, in large terminal panicles. Fruit broadly winged, like the Ash, but with the seed in the center. Ailénthus glandulosus, Desf. (TREE oF HEAVEN.) Leaves very large, 2 to 5 ft. long on the younger growths; leaflets obliquely lanceolate, coarsely toothed at the base, with a gland on the lower side at the point of each tooth; point of leaf- lets entire. Young twigs thick, rusty brown; buds very small in the axils. > Only some of the trees have fruit, as A. glanduldsua, G18] CLASSIFICATION AND DESCRIPTION 77 some have only staminate flowers. The staminate flowers are very ill-scented. A rapid-growing tree, with useful hard wood; cultivated and naturalized; hardy throughout. See page 10. ORDER XII. ILICINEZAS. (Hoty Famtity.) A small order of trees and shrubs, including for our purpose only one genus: Genus 18. ILEX. Trees or shrubs with simple, alternate, thick, mostly evergreen leaves. Flowers rather inconspicuous, mostly in clusters. Fruit berry-like, small (4 to 4 in.), with 4 to 6 nutlets; hanging on the plants late in the autumn or through the winter. * Leaves evergreen. (A.) A. Leaves with spiny teeth. ......... sip uglaheainaneadinace aeeae ba Peidins 1. A INO Spiny P66 s, sencie sd apc a Secislebeemed ahaa gs eae 2. * Leaves deciduous .... 1. cece eee e eee ne nne 3. 1. Hex opaca, Ait. (AMERICAN HOLLY.) Leaves evergreen, oval, acute, thick, smooth, N with scattered spiny teeth. Flowers white; May. The bright-red berries, found only on some of the trees, remain on through the greater part of the winter. Small tree, 15 to 40 ft. high, I onaca. with very hard white wood ; wild in south- ern NewEngland and southward. A beau- tiful broad-leaved, evergreen tree which should be more extensively cultivated. North of latitude 41° it needs a protected situation. 1 d 22 ni 2. Ilex Dahéon, Walt. (Dauoon Hot- Ly.) Leaves 2 to 3 in. long, evergreen, oblanceolate or oblong, entire or sharply serrate toward the apex, with revolute I. Dahon, margins, not spiny. Young branches and 78 TREES OF THE NORTHERN UNITED STATES lower surface of the leaves, especially on the midrib, pubescent. Small tree, 10 to 30 ft. high; Virginia and south, with very hard, white, close-grained wood. Rarely cultivated. 3. ex monticola, Gray. Leaves de- eiduous, ovate to lance-oblong, 3 to 5 in. long, taper-pointed, thin, smooth, sharply serrate. Fruit red, on short stems, with the seeds many-ribbed on the back. Usu- ally a shrub but sometimes tree-like; damp woods in the Catskills and in the Alleghany Mountains. I. monticola. OrpER XITI. CELASTRACEZ. Shrubs with simple leaves and small, regular flowers, forming a fruit with ariled seeds. Gzenus 19. EUONYMUS. Shrubs somewhat tree-like, with 4-sided branchlets, op- posite, serrate leaves, and loose cymes of angular fruit which bursts open in the autumn. 1. Euénymus atropurpireus, Jacq. (BURNING-BUSH. WaHOoO.) Leaves peti- oled, oval-oblong, pointed; parts of the dark-purple flowers commonly in fours; pods smooth, deeply lobed, when ripe, cin- namon in color and very ornamental. Tall shrub, 6 to 20 ft. high; wild in Wiscon- sin to New York, and southward ; often cultivated. E. atropurpireus. v: 2, Euédnymus Europ#us, L. (EURo- PEAN SPINDLE-TREE OR BURNING-BUSH.) Leaves oblong-lanceolate, serrate, smooth; flowers and fruit commonly in threes on compressed stems; fruit usually 4-lobed, the lobes acute; flowers greenish-white; May; E. Europzeus. fruit abundant, scarlet, ripe in September. @ 20) CLASSIFICATION AND DESCRIPTION va) Generally a shrub, though sometimes tall enough (4 to 20 ft.) and trimmed so as to appear tree-like; twigs smooth, green or reddish- green. Extensively cultivated; from Europe. Huonymous Japonica (Chinese Box) with evergreen leaves 2 in. long is often cultivated. ORDER XIV. _RHAMNACEZ. (BUCKTHORN FAMILY.) An order mainly of shrubs, but including in the north- eastern United States two or three small trees. Genus 20, RHAMNUS. Shrubs or small trees with deciduous (rarely evergreen), usually alternate (rarely opposite), pinnately veined leaves. Flowers small, 4-parted, inconspicuous, in clusters in the axils of the leaves. Fruit berry-like, with 2 to 4 seed- like nuts. * Branches terminating in thorns..... Se Aeeipalse els Veena sere ls * Plant without thorns. (A.) A. Leaves deciduous.............. sine Cidiaidialg GRC Ge MAE Oe A. Leaves evergreen . 0.6... eee cece eee eee nee en nets 3. 1. Rhémnus cathartica, L. (Common BuckTHorN.) Leaves ovate, minutely ser- rate, alternate or many of them oppo- site; branchlets terminating in thorns. Flowers greenish. Fruit ; globular, 4 in. in diameter, black A with a . green its ae juice, and 3 or R, cathartica. 4 seeds; ripe in September. A shrub or small tree, 10 to 15 ft. high, from Europe; cultivated for hedges, and found wild in a few places, where it forms a small tree. 2. Rhémnuus Caroliniana, Walt. (CaR- R, Oaroliniana, OLINA BucKTHORN.) Leaves 3 to 5 in. 8U TREES OF THE NORTHERN UNITED STATES long, alternate, oblong, wavy and obscurely serrulate, nearly smooth, on slender pubescent petioles. Flowers greenish, 5-parted, solitary or in umbellate clusters in the axils. Fruit berry-like, globular, the size of peas, 3-seeded, red and finally black in winter. A thorn- less shrub or small tree, 5 to 20 ft. high. New Jersey, south and west. Usually a shrub except in the South- ern States. 3. Rhaémnus Californicus,Esch. (CaL- IFORNIA BUCKTHORN.) Leaves evergreen, oval-oblong to elliptical, 1 to 4 in. long, rather obtuse, sometimes acute, generally rounded at base, serrulate or entire. Fruit blackish purple, with thin pulp, 4 in., 2- _ to 3-seeded. A spreading shrub, 5 to 18 ft. R. Californicus, high, without thorns; from California. GENUS 21. HOVENTIA. Leaves alternate, deciduous, simple, oblique at base. Fruit an obscurely 3-lobed, 3-celled, 3-seeded pod in dichotomous clusters, both axillary and terminal. Hovénia dalcis, Thunb. Leaves long- petioled, more or less ovate to cordate, serrate, palmately 3-ribbed, much darker on the upper surface; both sides slightly roughened with scattered hairs. Fruit sweet, edible, in clusters in the axils of the leaves; seeds lens-shaped, with a ridge on the inner side. Flowers white; in July. 4 A large, broad-topped tree, introduced H. dalcis. from Japan. Hardy at Washington, but dies to the ground in the Arnold Arboretum, Massachusetts. Genus 22. ZIZYPHUS. Leaves simple, alternate, deciduous, 3-ribbed. Flowers axillary, 5-petaled. Fruit fleshy, drupe-like, containing a 1- to 2-celled nut. Zizyphus vulgaris, Lam. (JusuBz.) Leaves ovate-lanceolate, obtuse, serrate, smooth, and glossy green on both sides, upper side @. 28] CLASSIFICATION AND DESCRIPTION 81 quite dark; slightly hairy beneath on the veins; prickles twin, one recurved, sometimes none. New growth of the year green, and resembling a once-pin- nate compound leaf and usually drop- ping off in the autumn like one. Leaves 10 to 20 on a twig, 2-ranked; flowers and drupes nearly sessile in the axils; fruit small (14 in.), blood-red when ripe. A small tree (10 to 30 ft. high), of recent introduction from Syria; hardy at Phila- delphia, but needing some protection at the Arnold Arboretum, Massachusetts. Z, vulgaris. ORDER XV. SAPINDACE ZS. (Soapperry Famiy.) A large order represented in all countries, and so varied in its characteristics as to form several sub-orders. Genus 23. ZESCULUS. Deciduous trees or sometimes shrubs, with opposite, palmately compound leaves with serrated, straight-veined leaflets. Flowers usually conspicuous in dense terminal panicles. Fruit large, leathery-coated, often rough, with one or few large Chestnut-like but bitter seeds. Fruit large in midsummer, hanging on the tree until frost. * Fruit prickly. (A.) A. Leaflets usually 7; flowers widely spreading.............. 1. A. Leaflets 5-7, red-spotted and rough ; flowers rosy red....... ag Slain we Bee Hn Heimat Sere inalenA chee a Rae gS Aisculus rubicunda (1). A. Leaflets usually 5; flowers not much spreading........... 2. * Fruit smooth or nearly so. (B.) B, Flowers-brightired. j6ic002 ganpaaa oon cpp essa aus cae eae e 3. B. Flowers yellow, purplish or pinkish............ 02.2.4. 4, B. Flowers white, in long, slender, erect clusters............ 5. 1. Asculus Hippocdstanum. (ComMMoN HoORSE-CHESTNUT. ) Leaves of 7 obovate, abruptly pointed, serrated leaflets. Flowers fi 82 TREES OF THE NORTHERN UNITED STATES very showy in large clusters, with 5 white, purple and yellow spotted, broadly spread- ing petals. A variety with double flowers is in cultivation. May or June. Fruit large, covered with prickles. Seeds large, chestnut-colored. Tree of large size, with brown twigs; cultivated everywhere; from Asia. 4isculus rubicunda (Red-flowering Horse-chestnut) is frequent in cultiva- tion; leaflets 5 to 7, red-spotted and rough; flowers.rosy red. It is-probably a hybrid i between the common Horse-chestnut and 28, Hippocéstarum. one of the Buckeyes. 2. Aisculus glabra, Willd. (OHIO Buckeye.) Leaves with 5 oval-oblong, acuminate, serrate, smooth leaflets. Flowers not showy, yellowish-white, with 4 somewhat irregular, slightly E spreading petals. June. Fruit small, 1 in. in diame- ter, covered with prickles, at least when young; ripe in autumn. Small to large tree, wild in the basin of the Ohio River, along 3 river-banks. Some- 2. glabra. times cultivated. ®, rubicanda, 3. Zsculus Pavia, L. (Rep BucKEYE.) Leaves of 5 to 7 oblong- lanceolate, finely serrate, generally smooth leaflets, of a shining green color, with purple veins and petioles. Flowers (corolla and calyx) bright red, with included stamens; corolla of 4 petals, not spreading; calyx tubular. Fruit smooth, ob- long-obovate, lin. long. Small tree or shrub, 10 to 20 ft. high, with purple twigs. Virginia west and south, and occasionally cultivated throughout. 2B. Pavia. 4, Aisculus flava, Ait. (SWEET BUCKEYE.) Leaves with 5 to 7 serrulate, elliptical, acuminate leaflets, usually smooth, sometimes G. 24} CLASSIFICATION AND DESCRIPTION 83: minutely pubescent beneath; the pubes- cent petiole flattish toward the base. Flowers yellow, not spreading. Spring. Fruit globose, uneven but not prickly, 2in. indiameter. Seeds large (lin.), 1 or 2 in number, mahogany-colored; ripe in % autumn. Often a large tree, sometimes only ashrub, 6 to 70ft. high, in rich woods; Virginia to Indiana, and southward. Cul- tivated oc- casionally throughout. ae Bava: Var. purpurascens of this species has flesh-colored or dull-purple flowers, and leaflets quite downy beneath. 5. A@isculus parviflora, Walt. (Lone-RaceMED Buckeye.) Leaflets 5 to 7, ovate, acuminate, serrate, vel- vety with hairs beneath. Flowers white, in long, slender, erect clusters ; July; petals 4, spreading; stamens very long. small tree, 2 to 20 ft. high, common, es- 8. longifolia, pecially westward, along river-banks. > Genus 92. POPULUS.. Trees with alternate, deciduous, broad-based leaves. Flowers in long and drooping catkins, appearing before the leaves are expanded in the spring. Fruit small, dry pods in catkins, having seeds, coated with cottony down, which early in the season escape and float in the wind. On this account. the trees are called Cottonwoods in the West. Trees with light-colored, rather soft wood. * Leaves always white-hairy underneath; more or less deeply lobed; buds not gummy .... 6. 6.1... . cece eee eee 1. * Leaves smooth beneath, at least when old. (A.) A. Leafstalk decidedly flattened laterally. (B.) B, Buds not covered with sticky gum. (C.) 168 TREES OF THE NORTHERN UNITED STATES C. Leaves roundish heart-shaped; bark on trunk greenish- PIG 256 fee nb Ao Ad Molebdeveant id aden Mnem da iteemank GS ans 2. C. Leaves large, ovate, with large, irregular, sinuate HOCH: cera sotasanreaiee aia Kehoe niaeakeee CaaS 3. B. Buds covered with aromatic, glutinous resin. (D.) D. Tree tall, spire-shaped...............cce eee eee eee 5. D. Not very spire-shaped; young twigs sharply angled or winged, leaves 6 to 10 in. long, broadly deltoid, serrate with incurved teeth ....... 0.0... c eee eee eet eee 6. D. Not spire-shaped; young twigs not angular ........ 7. A. Leafstalk not decidedly flattened; leaf-margin crenate. (E.) E. Buds not glutinous; leaves white-woolly beneath when E. Buds very glutinous; leaves large, shining green on both BIOS 4 Saye es dais bons view Mimienes cAsaceatec eee ees 8. “I P. alba. 1. Pépulus alba, L. (WHITE PoPLaR oR ABELE TREE.) Leaves roundish, slightly heart-shaped, wavy toothed or lobed, soon greer above, very white-cottony beneath even when old; buds without the sticky coating common in the genus. Branches very white with down when young. Root creeping and producing numerous suckers. A large tree, 50 to 80 ft. high, of rapid growth, often cultivated; from Europe. Leaves and branches very variable, forming several named varieties in the catalogues of the nurseries. 2. Pépulus tremuloides, Michx. (QUaK- ING-ASP. AMERICAN ASPEN.) Leaves round- ish heart-shaped, with w short sharp point, and small, quite regular teeth; downy when young, but soon smooth on both sides; margins downy. Leafstalk long, slender, L 4 P. tremuloides. compressed, causing the leaves to tremble continually in the slight- est breeze. Leaf with 2 glands at the base on the upper surface ; buds varnished. A medium-sized tree, 30 to 60 ft. high; bark greenish- white outside, yellow within, quite brittle. and in cultivation. Common both in forests 3. Populus grandidentata, Michx. (LARGE-TOOTHED ASPEN.) Leaves large, 3 to 5 in. long, roundish-ovate, with large, irregular, sinu- G. 92] CLASSIFICATION AND DESCRIPTION 169 ate teeth; and when young densely cov- ered with white, silky wool, but soon be- coming smooth on both sides; leaf, when young, reddish-yellow; petiole com- pressed. A large tree, 60 to 80 ft. high, with rather smoothish gray bark. Woods; common northward, rare southward, ex- cept in the Alleghanies. Wood soft and extensively used for paper-making. P, grandidentata. 4. Populus heterophylla, L. (Downy- LEAVED PopLaR.) Leaves heart-shaped or roundish-ovate with small, obtuse, in- curved teeth; white-woolly when young, but soon becoming smooth on both sides except on the veins beneath. Leafstalk slightly compressed. Shoots round, to- mentose. Buds not glutinous.