A SOUTHERN MICHIGAN WOODLOT

UNIVERSITY BULLETIN

UNIVERSITY OF MICHIGAN
BOTANICAL GARDEN AND ARBORETUM

MICHIGAN TREES

A HANDBOOK OF THE NATIVE AND MOST
IMPORTANT INTRODUCED SPECIES

By
CHARLES HERBERT OTIS, formerly Curator
WITH AN INTRODUCTION BY
GEORGE PLUMER BURNS, formerly Director

Ann Arbor
PUBLISHED BY THE REGENTS
1915

Copyright, 1915
BY
THE REGENTS OF THE UNIVERSITY OF MICHIGAN
THIRD EDITION, REVISED
THE ANN ARBOR PRESS, PRINTERS
ANN ARBOR, MICH.

TABLE OF CONTENTS.

MAP OF MICHIGAN
Showing Only Locations Mentioned in the Manual

INTRODUCTION

The idea of a bulletin on Michigan trees was first suggested by Prof. Volney M. Spalding. It was thought that a bulletin devoted entirely to the study of certain phases of tree life in Michigan would stimulate interest in the study of our trees, and influence many more people to associate themselves with the growing number of tree lovers and with the supporters of the movement for better forest conditions in the state.

The bulletin has been under consideration for a number of years and much of the material given herein has been used in the classes in forest botany at the University of Michigan. It remained, however, for the present Curator of the Botanical Garden and Arboretum to get the material into shape for publication, and the present bulletin is the result of his industry and perseverance. The preparation of the drawings and manuscript has been made by him in connection with his work in the Garden.

The distinctive feature of the bulletin lies in its keys. The keys commonly published are based upon characters which are present but a short time during the year, or which can be used only by an advanced student of botany. This bulletin presents two keys. One is based upon characters which are present all summer; the other uses the winter characters as a basis for identification. By the use of the keys any person should be able to name and learn the characteristics of the trees of Michigan at any time of the year. These keys should prove of special value to our students in the public schools, to members of nature study clubs, and to the students in the forestry schools of the state.

The order of arrangement and the nomenclature are essentially those of “Gray’s New Manual of Botany.” Following a tendency which is steadily gaining favor, all species names are printed with a small letter, regardless of their origin. For the convenience of the general reader, other scientific names which are found in botanical manuals in common use are printed in parenthesis. In the case of exotics which are not included in the Manual, other authorities have been followed. Sudworth’s “Check List of the Forest Trees of the United States” (U. S. Dept. Agr., Div. Forestry, Bul. 17) is in most cases authority for the common names. They are names appearing in common use today in some part of the state. The first name given is that recommended by Sudworth for general use.

The drawings have been made from living or herbarium material and are original. They are accurately drawn to a scale, which is given in each case. In their preparation the author has endeavored to call attention to the salient characters. In the drawings of buds and twigs certain points, bundle-scars, etc., have been emphasized more than is natural. In the descriptions the attempt has been made to bring out those points of similarity and contrast which are most useful for identification.

As the bulletin is not written especially for technical students of botany, the author thought best to use as few technical terms as possible in the descriptions. In some cases it was impossible to avoid such terms, but with the help of the glossary the meaning can be easily understood. Any person desiring to get a more complete knowledge of trees should consult one of the larger manuals. The arrangement used for the illustration and discussion of each single tree makes it possible for the student to compare the drawings with the description without turning a page.

It is believed that with the aid of the drawings and descriptions given in this bulletin any person will be able to name the trees which grow in his yard, park, or woodlot. If, however, any difficulty is found in naming the trees, the Curator will be glad to name any specimens which may be mailed to him. He would be glad to get in touch with persons interested in Michigan trees and to receive any additional information relating to the subject. Data concerning the distribution of the trees in the state, and the addition of other Michigan trees to the present list would be of especial value.

George Plumer Burns.

ACKNOWLEDGMENTS

Grateful acknowledgment is hereby made to Miss Sarah Phelps, who has done most of the inking in and given life to the author’s pencil-drawings; to Mr. J. H. Ehlers for his valuable assistance in the preparation of many of the drawings and in the collection of working material; to Prof. Henri Hus, who has read all of the proof and who has at various times rendered valuable assistance; to Prof. F. C. Newcombe and to Prof. Ernst Bessey for the loan of sheets, from the herbariums of the University of Michigan and Michigan Agricultural College; and especially to Prof. Geo. P. Burns in whose inspiration this bulletin had its inception and under whose direction the work has progressed to completion.

Chas. H. Otis.

HOW TO STUDY THE TREES

People are everywhere associated with trees. Trees give cooling shade in our parks and dooryards and along our highways; they lend their beauty to the landscape and relieve it of monotony; they yield many kinds of fruits, some of which furnish man and the animals of the forest with food; and they furnish vast quantities of lumber for a multitude of uses. How important it is, then, that every person, whether school-child or grown-up, should become acquainted with our trees. Most people know a few of our commonest trees, but are ignorant of the great wealth of tree forms about them. Some who may have wished to go further have been hindered for lack of a teacher or dismayed by the very multitude of manuals to which they have had access.

In beginning a study of the trees the student should start on a solid foundation, eliminating the uncertainties and the errors which no doubt have appeared and retaining only the established facts. Once started he should go slowly, assimilating each new discovery before seeking another. He should begin with the trees nearest home, and, as he gradually grows to know these in all their aspects, should extend his trips afield. Not only should he be able to name the trees when they are fully clothed in their summer dress, but he should as readily know these same trees when the leaves have fallen and only the bare branches stand silhouetted against the sky. Then, and only then, will he derive the utmost satisfaction from his efforts.

The characters which are used in studying the trees are habit, leaves, flowers, fruit, buds, bark, distribution and habitat. These will be discussed briefly in the next few pages, the same order that is used in the detailed descriptions of species being maintained in the present discussion. A few drawings will also be added to make clear certain points and to show comparative forms.

NAME.—Every tree has one or several common names and a scientific or Latin name. Some of these common names are merely local, others have a more extended use. Some few names apply to totally different species. Thus, Cottonwood in Michigan is Populus deltoides, in Idaho and Colorado Populus angustifolia, in California Populus fremontii and in Kentucky Tilia heterophylla. While it should not be forgotten that in common speech it is proper as well as convenient to call trees by their common names, yet, in view of the many uncertainties pertaining to their use, a scientific name is at times absolutely essential to the clear understanding of what is meant. Latin is the language in universal use by all scientists. No longer used by any civilized nation, it has become a dead language and consequently never changes. Its vocabulary and its constructions will a thousand years hence be the same as they are today. Being in universal use among scientists of all nationalities no confusion arises from the use of a Latin word. The Oak in Germany is known as Eiche, in France as chêne and in Spain as roble, but the Latin word Quercus is the same for all these countries.

A scientific name as applied to trees consists of at least two parts, as Quercus alba; the first named is the genus and is always written with a capital letter, the second is the species and is written with a small letter, the two names constituting the briefest possible description of the particular tree. It is customary to add to these the name or an abbreviation of the name of the person who first gave the name to the tree, as Quercus alba L., the abbreviation standing for Linnaeus. Sometimes a third name is used, as Acer saccharum nigrum, referring in this case to a variety of the ordinary Sugar Maple.

Genera which bear a relationship to each other are placed in the same family, the family name always having the characteristic ending—aceae. Related families are again grouped into orders, with the characteristic ending—ales. Orders are in like manner arranged into larger groups, called classes, and the latter into still larger groups, divisions, etc., each with its characteristic ending. Thus, Acer saccharum nigrum (Michx. f.) Britt. is classified as follows:

Division—Spermatophyta
Subdivision—Angiospermae
Class—Dicotyledoneae
Order—Sapindales
Family—Aceraceae
Genus—Acer
Species—saccharum
Variety—nigrum.

HABIT.—Habit, or the general appearance of a plant, is an important character of identification, especially as we become more and more familiar with the trees. Two main types are recognized, based on the manner of branching of the trunk, the upright and the spreading. In the one the trunk extends straight upwards without dividing, as is typical in most of the conifers, and in the other the trunk divides to form several large branches and the broad, spreading crown of most of our broad-leaf trees. The crown in either case may be regular in outline or very irregular, straggling or straight-limbed. Moreover, the tree growing in the open, where there is no crowding and there is plenty of light, may differ very greatly from the tree in the forest, where the struggle for existence becomes very keen. A short, thick trunk and low, spreading, many-branched crown characterizes the tree in the open, whereas the forest tree has a long, slender, clean trunk and a narrow crown of few branches. In the descriptions of trees in this bulletin, unless otherwise stated, the habit in the open is the one given. Again, the tree may have been injured by storm or insect at some period of its growth and its natural symmetry destroyed. Moreover, the age of a tree has a great influence on its outline, young trees being generally narrow and more or less conical, broadening out as they become older. We may say, then, that each tree has an individuality of its own, little eccentricities similar to those that make people different from one another. And just as we have little difficulty in recognizing our friends at a distance by some peculiarity of walk or action, so are we able to recognize a great many trees at a distance by some peculiarity of form or habit.

I. LEAF OUTLINES

II. LEAF TIPS

LEAVES.—With the advent of spring the buds of our broad-leaf trees swell and burst and the leaves come forth and clothe the trees with mantles of green, hiding the branches which have been bare through the cold winter months. The evergreens, too, take on new color and begin a new period of growth. It is the leaves which the beginner finds most interesting and in which he finds a ready means of identification. It must be remembered, however, that leaves vary greatly in size and shape and general appearance. How large are the leaves on a flourishing sprout and how small on a stunted tree of the same species growing near by, but under adverse circumstances. How different are the leaves of the big white oak standing in the yard; they are hardly lobed on the lowermost branches, while higher up they are deeply cut. Yet, in spite of the many modifications that leaves undergo, the leaves of any one species have certain rather constant characters which are found in all forms, and the student will have little difficulty in selecting and recognizing typical leaves.

III. LEAF MARGINS

Serrate. Doubly Serrate. Crenate. Undulate. Sinuate. Lobed. Dentate.

Leaves are either persistent, as in most of our conifers, which stay green all winter, or they turn various colors with the frost and fall early in autumn; often they hang dead and lifeless far into the winter. The points about leaves which we are accustomed to consider are the position or arrangement of the leaves on the branch, whether simple or compound, size, shape, texture, color, amount and character of pubescence, character of the margin, venation, etc. The following diagrams will serve to illustrate some of the ordinary forms and shapes of leaves, their margins, etc.

IV. PARTS OF A FLOWER

Perfect Flower. Stamen. Pistil.

FLOWERS.—Every tree when old enough bears flowers in its proper season. Some of these, as the Catalpas, Locusts and Horse-chestnuts are very showy, others, like the Oaks and Hickories, are comparatively inconspicuous; some are brilliantly colored, others are of the same color as the leaves. Nevertheless, the flowers are very accurate means of classification, and their only drawback is that they last for such a short period of time each year.

Just as we have male and female in the animal world, so we have male and female in the plant world. A few of our trees, as the Locust, Basswood and Cherries have perfect flowers, bearing both stamens and pistil. The great majority, however, have unisexual flowers, bearing stamens or pistils, but not both. When both male and female flowers are found on the same tree, the flowers are said to be monoecious, and when male flowers occur on one tree and the female on a different tree, the flowers are said to be dioecious. The Cottonwood is dioecious, and the little seeds are surrounded by a tuft of long, white hairs which enables the wind to carry them to considerable distances from the parent tree, to the disgust of people living within range. Many cities forbid the planting of Cottonwood on account of the “cotton.” Since in some cases it is desirable to plant this rapid-growing tree, as in cities burning large amounts of soft coal, it is a distinct advantage to know that male trees are lacking in the objectionable “cotton” and may be planted safely.

V. TYPES OF INFLORESCENSES

Before trees can produce fruit their flowers must be fertilized, i.e., pollen from the anther of a stamen must come in contact with the stigma of a pistil. Some flowers are self-fertilized, others are cross-fertilized. For a long time it was not known how fertilization was accomplished, but now we know that many insects, like the nectar-loving bees and butterflies, and in other cases the wind transport the pollen from one flower to another, often miles being traversed before the right kind of flower or a flower in the right stage of development is found. And many are the modifications of flowers to insure this transference of pollen.

FRUIT.—So numerous and so varied are the forms of tree fruits that it would only be confusing to enumerate their various characters. Some fruits, as the achenes of the Poplars and Willows, are so small and light that they are carried long distances by the wind; others, like the hickory nuts and walnuts, are too heavy to be wind-blown. Many fruits are of considerable economic and commercial importance and are gathered and marketed on a large scale; such are the hickory nuts, walnuts, chestnuts, etc. Some, not esteemed by man, form an important article of diet for the birds and small animals of the forest. Unfortunately, there are a number of limitations to the usefulness of fruit for identification purposes. Some trees require years to mature their fruit. Many trees, while producing an abundance of fruit at certain intervals, bear none at all or only very small and uncertain quantities between the years of abundance. Again, in the case of dioecious trees, only the female or pistillate bear fruit. Notwithstanding these limitations tree fruits are a very valuable aid to the student, and he should always search closely for evidences of their presence and character.

VI. WINTER
TWIG OF RED
MULBERRY

a. Tip-scar.
b. Lateral bud.
c. Leaf-scar.
d. Stipule-scars.

WINTER-BUDS.—Buds, with their accompanying leaf-and stipule-scars form the basis of tree identification in winter. The size, color, position with reference to the twig, number and arrangement and character of bud-scales, etc., are all characters of the greatest value in winter determinations. Buds are either terminal or lateral, depending on their position on the twig. A lateral bud is one situated on the side of a twig in the axil of a leaf-scar. A terminal bud is one situated at the end of a twig, where it is ready to continue the growth of the twig the following spring. In the keys an important consideration is the presence or absence of the terminal bud. Inasmuch as the determination of this point gives the beginner some trouble at first, it is hoped that the accompanying diagrams and explanatory remarks will make the distinction clear.

VII. WINTER
TWIG OF BLACK
WALNUT

a. Terminal bud.
b. Lateral bud.
c. Leaf-scar.
d. Bundle-scars.
e. Pith.

In the Elms, Willows, Basswood and many other species the terminal bud and a small portion of the tip of the twig dies and drops off in late autumn, leaving a small scar at the end of the twig (a, fig. VI). The presence of this tip-scar indicates that the terminal bud is absent. Often a lateral bud will be found very close to the tip-scar (b, fig. VI), which, bending into line with the twig, makes it appear terminal. However, the presence of a leaf-scar immediately below it shows it to be a lateral bud (c, fig. VI). In some large twigs the eye unaided will serve to find the tip-scar, but with the smaller twigs a hand-lens is necessary.

The arrangement, size and shape of the leaf-scars (c, fig. VII) are important factors in identification by winter characters. Within the leaf-scars are one or more dots (d, fig. VII), sometimes quite inconspicuous, often very prominent. These are the scars left by the fibro-vascular bundles which run through the petiole into the blade of the leaf, and are designated as bundle-scars. There may be only one as in Sassafras and Hackberry, two as in Ginkgo, three as in the Poplars and Cherries, or many; and they may be arranged in a U- or V-shaped line, or they may be without definite order. Often stipule-scars (d, fig. VI) occur on either side of the leaf-scar; these are scars left by the fall of a pair of small leaflets called stipules and located at the base of the leaves, and their form varies according to the form of the stipules which made them.

BARK.—The woodsman uses the bark of a tree more than any other character in distinguishing the trees about him, and he is often able to use this character alone with much accuracy at great distances. However, the appearance of bark differs so greatly with the age of the tree and with its environment that it is difficult to describe it accurately. Some characters are distinctive, however, and serve as a ready means of identification; such characters are the peeling of the Sycamore and Paper Birch, the “shagging” of the Shagbark Hickory, the spicy taste of Sassafras bark and the mucilaginous inner bark of the Slippery Elm.

WOOD.—It is not expected that the information given under this heading will be of any particular value in identifying living trees. Often, however, the student finds himself in the midst of felling operations, when the information concerning the wood is of considerable value.

DISTRIBUTION AND HABITAT.—To a lesser extent do distribution and habitat of a species aid in the identification of a tree. It is a distinct aid to know that the Chestnut is native in south-eastern Michigan only and that the Mountain Ash does not extend south of Ludington. So too, knowing the water-loving habit of the Swamp White Oak, we would not expect to find this same tree flourishing on the top of a hard, dry hill.

The characters, then, which are used to identify the trees about us are many. Not all will be available at any one time, not all have been mentioned in the foregoing pages nor in the manual. It is our opinion, however, that the student will not be greatly handicapped by this lack of detail, but rather that he will take great interest and genuine pleasure in discovering these things for himself.

ARTIFICIAL KEYS, HOW MADE AND USED

An artificial key is a scheme for easily and quickly identifying any unknown object under consideration. This bulletin being devoted to the trees of Michigan, the keys to be found herein are intended to make it possible for any person, even if his botanical training be meager, to determine what trees grow about any home or farm, city park or woodlot in the state. With certain modifications and limitations they may prove useful in other localities as well. Since many people are unfamiliar with the construction and use of keys for identification, it will be the purpose of the following paragraphs to briefly outline the principles of construction and the manner of using the keys to be found here.

The keys are based on the most striking similarities and differences which the various parts of trees—twigs, buds, leaves, etc.—show, i. e., those characters which stand out in bold relief, which catch the eye at first sight. Two alternatives are presented, either a character is or is not present; these are the only choices possible. Indeed, further divisions are unnecessary and only lead to confusion and possible oversight. The two diametrically opposed characters are said to be coördinate in rank. In the keys they are preceded by the same letter or letters (a and aa or b and bb, etc.) and are set at the same distance from the left margin of the page. Often a and aa, or b and bb are further divisible into other groups; in every case the characters are opposed (a positive and a negative) and are given coördinate rank. It is desirable for mechanical reasons to divide the main divisions of the key more or less evenly, but this is not always feasible, nor should it be religiously adhered to.

Suppose as a concrete example that it is desired to construct a key to distinguish five houses in a city block. Three of these are of wood construction, two are of brick, and of the two wooden houses one is painted white and one brown. We may classify them as follows:

It is desirable in many cases to add other characters to lessen the liability of confusion, where the characters chosen are not distinct, and to show the user that he is on the right track. Thus, in the example just given, green color and slate color under certain defects of the eye, a coating of dust or deficiencies of the light might be confused, under which circumstances we would be justified in adding to the above statements without the criticism of description being made. Thus:

The keys in this bulletin are constructed on the above principles. They are not in all cases as simple as the illustration just used, but if the reader has mastered the house illustration he will have little or no trouble with the larger keys. Suppose that (during a summer stroll) you come across a large tree with rough, hard bark and thin, lobed leaves which you do not know. Turning to the Summer Key to the Genera you find first a. Leaves simple, and contrasted with this aa. Leaves compound. Obviously the leaf is simple and the genus sought lies in that portion of the key preceding aa, i.e., under a. b and bb under a give you a choice between Leaves needle-shaped, awl-shaped, strap-shaped or scale-like and Leaves broad and flat. The leaf being broad and flat you pass to c and cc under bb. Here you have a choice between Leaves alternate or clustered and Leaves opposite or whorled. Inspection shows the arrangement to be opposite, and you know that the genus sought lies in that portion of the key between cc and aa. Passing to d and dd under cc gives the choice between Margin of leaves entire or only slightly undulate and Margin of leaves serrate to lobed. The leaf is deeply lobed. It is then either a Viburnum or an Acer, and the fact that the leaf-margin is lobed and not finely serrate brings the chase down to Acer. Before going further go back over the key and make careful note of the particular characters which were used to separate this genus from the other genera and try to fix these in mind. This done, turn to the page indicated, where you will find a Summer Key to the Species of Acer. You run through this key in the same manner that you did the genus key. If you have been careful in your search you will finally stop at Acer saccharum. Once more pause and go back over this key and try to fix in mind the characters which were used to separate the various species, especially the difference between your tree and Acer platanoides, which it so closely resembles. This done, turn to the page indicated and compare the characters of your tree with the drawings and descriptions. If you are satisfied with your diagnosis, well and good. If you find that you are wrong, go over the keys again and find wherein you were led astray.

Before you leave the tree take a sample of leaf properly labeled which you can press between the pages of an old magazine and save for future reference. Do this with other trees which you may find and when you get home lay them out side by side so that the labels will not show and compare them. A few trials of this kind will serve to form a mental picture of each leaf which you will remember.

A very helpful practice for the beginner is that of making keys based upon various characters. Practice keys of this kind will bring out the differences and likenesses of trees as will no other means, and characters which have hitherto escaped the eye will be prominently brought forward. Nor should the student take his characters from books, but rather should he go to the woods and get his knowledge first hand.

It is hardly necessary to state that the key is a valuable crutch while learning to walk, but once the leg is strong enough to bear the weight it should be discarded, lest it become a burden. A key has for its main object the guidance of the student through the preliminary steps leading to a more intimate knowledge of the trees. When once he knows a tree, instinctively, because of long acquaintance with it, just as he knows people, then the need for a key will have ceased.

SUMMER KEY TO THE GENERA [A]

WINTER KEY TO THE GENERA[B]

MANUAL OF TREES

DESCRIPTION OF SPECIES

WITH

SUMMER AND WINTER KEYS
TO THE SPECIES

GINKGOACEAE

Ginkgo. Maidenhair Tree

1. Winter twig, × 1/2.

2. Leaf, × 1/2.

3. Staminate flowering branchlet, × 1/2.

4. Staminate flower, enlarged.

5. Pistillate flower, enlarged.

6. Fruit, × 1.

GINKGOACEAE

Ginkgo.[C] Maidenhair Tree

Ginkgo biloba L. [Salisburia adiantifolia Smith]

HABIT.—A slender tree in youth, with slender, upright branches, becoming broader with age and forming a symmetrical, pyramidal crown; probably 60-80 feet high, with a trunk diameter of 2-4 feet.

LEAVES.—Clustered at the ends of short, spur-like shoots, or scattered alternately on the long terminal branches; simple; 2-5 inches broad; more or less fan-shaped; usually bilobed and irregularly crenate at the upper extremity; thin and leathery; glabrous, pale yellow-green on both sides; petioles long, slender; turning a clear, golden yellow before falling in autumn.

FLOWERS.—May, with the leaves; dioecious; the staminate in short-stalked, pendulous catkins, 1 to 1-1/2 inches long, yellow; the pistillate more or less erect on the shoot, long-stalked, consisting of 2 naked ovules, one of which usually aborts.

FRUIT.—Autumn; a more or less globose drupe, orange-yellow to green, about 1 inch in diameter, consisting of an acrid, foul-smelling pulp inclosing a smooth, whitish, somewhat flattened, almond-flavored nut.

WINTER-BUDS.—Terminal bud about 1/8 inch long, conical, smooth, light chestnut-brown; lateral buds divergent, usually only on rapid-growing shoots.

BARK.—Twigs gray-brown and smooth; thick, ash-gray and somewhat roughened on the trunk, becoming more or less fissured in old age.

WOOD.—Light, soft, weak, close-grained, yellow-white to light red-brown, with thin, lighter colored sapwood.

NOTES.—Origin in dispute, but probably a native of northern China. Extensively cultivated in China and Japan, where its fruit is esteemed. Easily propagated from seed. Thrives in deep, well-drained, rich soil. Practically free from insect and fungous attacks, and little harmed by the smoke of cities. Probably hardy throughout the southern half of the Lower Peninsula.

PINACEAE

SUMMER KEY TO THE SPECIES OF PINUS

WINTER KEY TO THE SPECIES OF PINUS

White Pine

1. Cluster of leaves, × 1.

2. Cross-sections of leaves, enlarged.

3. Partly opened cone, × 3/4.

4. Cone-scale with seeds, × 1.

PINACEAE

White Pine

Pinus strobus L.

HABIT.—A large tree 60-80 feet high, with a trunk diameter of 2-4 feet; forming a wide, pyramidal crown. Formerly trees 100-150 feet in height and 5-7 feet in trunk diameter were not exceptional.

LEAVES.—In clusters of five; 3-5 inches long; slender, straight, needle-shaped, 3-sided, mucronate; pale blue-green. Persistent about 2 years.

FLOWERS.—June; monoecious; the staminate oval, light brown, about 1/3 inch long, surrounded by 6-8 involucral bracts; the pistillate cylindrical, about 1/4 inch long, pinkish purple, long-stalked.

FRUIT.—Autumn of second season, falling during the winter and succeeding spring; pendent, short-stalked, narrow-cylindrical, often curved, greenish cones, 4-10 inches long; scales rather loose, slightly thickened at the apex; seeds red-brown, 1/4 inch long, with wings 1 inch long.

WINTER-BUDS.—Oblong-ovoid, sharp-pointed, yellow-brown, 1/4-1/2 inch long.

BARK.—Twigs at first rusty-tomentose, later smooth and light brown, finally thin, smooth, greenish; thick, dark gray on the trunk, shallowly fissured into broad, scaly ridges.

WOOD.—Light, soft, weak, compact, straight-grained, easily worked, light brown, with thin, whitish sapwood.

DISTRIBUTION.—Upper Peninsula and Lower Peninsula north of Allegan, Eaton and St. Clair Counties. Often planted as an ornamental tree farther south.

HABITAT.—Prefers a light, fertile loam; sandy soils of granite origin.

NOTES.—Rapid of growth. Small seedlings easily transplanted. Formerly very abundant, but rapidly nearing extinction through destructive lumbering.

Jack Pine. Scrub Pine

1. Cluster of leaves, × 1.

2. Cross-section of leaf, enlarged.

3. Branchlet with unopened cone, × 1.

4. Branchlet with opened cone, × 1.

5. Cone-scale with seeds, × 1.

PINACEAE

Jack Pine. Scrub Pine

Pinus banksiana Lamb. [Pinus divaricata (Ait.) Du Mont de Cours.]

HABIT.—Usually a small tree 20-30 feet high, with a trunk diameter of 8-12 inches; forming a crown varying from open and symmetrical to scrubby, stunted, and variously distorted.

LEAVES.—In clusters of two; about 1 inch long; narrow-linear, with sharp-pointed apex; stout, curved or twisted, divergent from a short sheath; dark gray-green. Persistent 2-3 years.

FLOWERS.—May-June; monoecious; the staminate in oblong clusters 1/2 inch long, composed of many sessile, yellow anthers imbricated upon a central axis; the pistillate in subglobose clusters, composed of many carpel-like, purple scales (subtended by small bracts) spirally arranged upon a central axis.

FRUIT.—Autumn of second or third season, but remaining closed for several years and persistent on the tree for 10-15 years; erect, usually incurved, oblong-conical, sessile cones, 1-1/2-2 inches long; scales thickened at the apex; seeds triangular, nearly black, 3/8 inch long, with wings 1/3 inch long.

WINTER-BUDS.—Terminal bud 1/4 inch long, ovoid, rounded, pale brown; lateral buds smaller.

BARK.—Twigs yellow-green, becoming purple, finally dark red-brown and rough with the persistent bases of fallen leaves; thin, dark red-brown on the trunk, with shallow, rounded ridges, rough-scaly on the surface.

WOOD.—Light, soft, weak, close-grained, light brown, with thick, whitish sapwood.

DISTRIBUTION.—Common from Clare County northward; occurs sparingly along the lake shore as far south as Grand Haven on the west and Port Austin on the east.

HABITAT—Sandy, sterile soil.

NOTES.—Cones open unevenly. Slow of growth. Difficult to transplant.

Austrian Pine. Black Pine

1. Cluster of leaves, × 1.

2. Cross-section of leaf, enlarged.

3. Unopened cone, × 1.

4. Partly opened cone, × 1/2.

5. Cone-scale with seeds, × 1.

PINACEAE

Austrian Pine. Black Pine

Pinus laricio austriaca Endl. [Pinus austriaca Höss.]

HABIT.—A large tree 60-80 feet high, with a trunk diameter of 2-4 feet; forming a massive, spreading crown of stiff, strong branches.

LEAVES.—In clusters of two; 3-6 inches long; slender, rigid, sharp-pointed, curved towards the twig; deep green on both faces. Persistent 3-6 years.

FLOWERS.—May-June; monoecious; the staminate cylindrical, subsessile, bright yellow, about 3/4 inch long; the pistillate cylindrical, small, bright red, subsessile.

FRUIT.—Autumn of first season, opening two years after full size is attained and remaining on the tree several years; erect, sessile, long-ovoid cones 2-3 inches long; scales smooth, lustrous, thickened at the apex and topped with a short spine in the center; seeds red-brown, 1/4 inch long, with wings 3/4 inch long.

WINTER-BUDS.—Oblong-conical, sharp-pointed, red-brown, resinous, about 1/2 inch long.

BARK.—Twigs brownish to olive-brown and smooth, becoming darker with age; thick, gray to nearly black on old trunks and coarsely and deeply fissured.

WOOD.—Light, strong, very resinous, red-brown, with thick, yellowish to reddish white sapwood.

NOTES.—Perfectly hardy. Adapts itself to a variety of soils. Well adapted for screens and wind-breaks. Easily transplanted when small. Grows rapidly.

Scotch Pine. Scotch Fir

1. Cluster of leaves, × 1.

2. Cross-section of leaf, enlarged.

3. Unopened cone, × 1.

4. Partly opened cone, × 1.

5. Cone-scale with seeds, × 1.

PINACEAE

Scotch Pine. Scotch Fir

Pinus sylvestris L.

HABIT.—A large tree 60-80 feet high, with a trunk diameter of 1-2 feet; the side branches persist, forming a massive, wide-spreading crown.

LEAVES.—In clusters of two; 1-1/2-3 inches long; stiff, more or less twisted, spreading slightly from a short sheath; bluish- or often glaucous-green. Persistent 3-4 years.

FLOWERS.—May-June; monoecious; the staminate ovoid, short-stalked, yellowish, about 1/4 inch long; the pistillate oblong, reddish, short-stalked, about 1/4 inch long.

FRUIT.—Autumn of second season, falling as soon as ripe; pendent, stout-stalked, ovoid-conical cones 1-1/2-2-1/2 inches long; scales dull gray-brown, thickened at the apex into 4-sided, recurved points; seeds red-brown, nearly 1/4 inch long, with wings about 3/4 inch long.

WINTER-BUDS.—Oblong-ovoid, sharp-pointed, red-brown, resinous, about 1/4 inch long.

BARK.—Twigs reddish to orange-brown, becoming grayish; thick, dark orange-brown on old trunks and coarsely and deeply fissured.

WOOD.—Light, stiff, straight-grained, strong, heavy, hard, resinous, red-brown, with thick, yellow to reddish white sapwood.

NOTES.—Very rapid of growth. Reaches perfection only in cold or elevated regions. Adapts itself to a variety of soils. A valuable ornamental tree. Very useful for screens or shelter belts.

Red Pine, Norway Pine

1. Cluster of leaves, × 1.

2. Cross-section of leaf, enlarged.

3. Opened cone, × 1.

4. Cone-scale with seeds, × 1.

PINACEAE

Red Pine. Norway Pine

Pinus resinosa Ait.

HABIT.—A large tree 70-80 feet high, with a trunk diameter of 2-3 feet; stout, horizontal branches, form a broad, rounded, rather open crown.

LEAVES.—In clusters of two; 4-6 inches long; slender, straight, needle-shaped, sharp-pointed, flexible, from elongated, persistent sheaths; lustrous dark green. Persistent 4-5 years.

FLOWERS.—April-May; monoecious; the staminate in oblong, dense clusters, 1/2-3/4 inch long, composed of many sessile, purple anthers imbricated upon a central axis; the pistillate single or few-clustered at the end of the branchlets, subglobose; scales ovate, scarlet, borne on stout peduncles covered with pale brown bracts.

FRUIT.—Autumn of second season, falling the next summer; ovoid-conical, nearly sessile cones, about 2 inches long; scales thickened at the apex; seeds oval, compressed, light mottled-brown, with wings 1/2-3/4 inch long.

WINTER-BUDS.—About 3/4 inch long, ovoid or conical, acute, red-brown, with rather loose scales.

BARK.—Twigs orange-brown, becoming rough with the persistent bases of leaf-buds; thick and red-brown on the trunk, shallowly fissured into broad, flat ridges.

WOOD.—Light, hard, very close-grained, pale red, with thin, yellow to white sapwood.

DISTRIBUTION.—Very abundant in Clare County and northward; frequent on the east side of the state as far south as Port Huron.

HABITAT.—Sandy plains and dry woods.

NOTES.—Rapid of growth on the better soils. Difficult to transplant.

Tamarack

1. Autumn branchlet, with leaves and cones, × 1.

2. Cross-section of leaf, enlarged.

3. Fruiting branchlet in winter, × 1.

4. Cone-scale with seeds, × 2.

PINACEAE

Tamarack

Larix laricina (DuRoi) Koch [Larix americana Michx.]

HABIT.—A tree sometimes 80-100 feet high, with a trunk diameter of 1-2 feet; forming a broad, open, irregular crown of horizontal branches.

LEAVES.—Scattered singly along the leading shoots or clustered on the short lateral branchlets; linear, with blunt apex; rounded above, keeled beneath; about 1 inch long; bright green; sessile. Deciduous in early autumn.

FLOWERS.—April-May, with the leaves, monoecious; the staminate sessile, subglobose, yellow, composed of many short-stalked anthers spirally arranged about a central axis; the pistillate oblong, short-stalked, composed of orbicular, green scales (subtended by red bracts) spirally arranged about a central axis.

FRUIT.—Autumn of first season, but persistent on the tree for a year longer; ovoid, obtuse, light brown, short-stalked cones, 1/2-3/4 inch long; seeds 1/8 inch long, with pale brown wings widest near the middle.

WINTER-BUDS.—Small, globose, lustrous, dark red.

BARK.—Twigs at first grayish, glaucous, later light orange-brown, and finally dark brown; red-brown and scaly on the trunk.

WOOD.—Heavy, hard, very strong, coarse-grained, very durable, light brown, with thin, nearly white sapwood.

DISTRIBUTION.—Common throughout the state.

HABITAT.—Prefers cold, deep swamps, or in the north coming out on the drier uplands.

NOTES.—Becomes a picturesque tree in old age. Should be transplanted while dormant.

SUMMER KEY TO THE SPECIES OF PICEA

WINTER KEY TO THE SPECIES OF PICEA

White Spruce

1. Winter branchlet, x.

2. Leaves, × 1.

3. Cross-section of leaf, enlarged.

4. Unopened cone, × 1.

5. Partly opened cone, × 1.

6. Cone-scale with seeds, × 1.

PINACEAE

White Spruce

Picea canadensis (Mill.) BSP. [Picea alba Link]

HABIT.—A tree 50-60 feet high, with a trunk diameter of 1-2 feet; forming a rather broad, open, pyramidal crown.

LEAVES.—Spirally arranged, but crowded on the upper side of the branches by the twisting of those on the under side; awl-shaped, 4-sided, incurved; dark blue-green; about 3/4 inch long; ill-scented when bruised. Persistent for several years.

FLOWERS.—April-May; monoecious; the staminate oblong-cylindrical, long-stalked, 1/2-3/4 inch long, composed of many spirally arranged, red anthers; the pistillate oblong-cylindrical, composed of broad, reddish scales (subtended by orbicular bracts) spirally arranged upon a central axis.

FRUIT.—Autumn or early winter of first season, falling soon after discharging the seeds; pendent, slender, oblong-cylindrical, nearly sessile cones, 1-2 inches long; seeds about 1/8 inch long, with large wings oblique at the apex.

WINTER-BUDS.—Broadly ovoid, obtuse, light brown, 1/8-1/4 inch long.

BARK.—Twigs smooth, gray-green, becoming orange-brown, finally dark gray-brown; thin, light gray-brown on the trunk, separating into thin, plate-like scales.

WOOD.—Light, soft, weak, straight-grained, light yellow, with sapwood of the same color.

DISTRIBUTION.—Common in the northern half of the Lower Peninsula and throughout the Upper Peninsula.

HABITAT.—Low, damp woods; banks of streams; borders of lakes; high rocky or sandy slopes; loves the cold winters.

NOTES.—A vigorous and beautiful tree in regions sufficiently cold.

Black Spruce

1. Winter branchlet, × 1.

2. Leaves, × 2.

3. Cross-sections of leaves, enlarged.

4-5. Opened cones, × 1.

6. Cone-scale with seeds, × 1.

PINACEAE

Black Spruce

Picea mariana (Mill.) BSP. [Picea nigra Link]

HABIT.—A small tree 20-30 feet high, with a trunk diameter of 6-10 inches; forming a narrow-based, conical, more or less irregular crown of short, slender, horizontal branches; often small and stunted.

LEAVES.—Spirally arranged, spreading in all directions; awl-shaped, 4-sided, blunt at the apex, more or less incurved; stiff; dark blue-green and glaucous; 1/8-3/8 inch long. Persistent for several years.

FLOWERS.—April-May; monoecious; the staminate subglobose, about 1/2 inch long, composed of many spirally arranged, dark red anthers; the pistillate oblong-cylindrical, composed of broad, purple scales (subtended by rounded, toothed, purple bracts) spirally arranged upon a central axis, about 1/2 inch long.

FRUIT.—Autumn of first season, but persistent on the branch for many years; pendent, ovoid, short-stalked cones, about 1 inch long; seeds about 1/8 inch long, with pale brown wings 1/2 inch long.

WINTER-BUDS.—Ovoid, acute, light red-brown, puberulous, 1/8 inch long.

BARK.—Twigs at first green and rusty-pubescent, becoming dull red-brown and rusty-pubescent; thin, gray-brown on the trunk, separating into thin, appressed scales.

WOOD.—Light, soft, weak, pale yellow-white, with thin, pure white sapwood.

DISTRIBUTION.—Occurs sparingly in southern Michigan; more abundant in the northern portions.

HABITAT.—Cold, sphagnous bogs and swamps; shores of lakes.

NOTES.—Short-lived. Undesirable for ornamental planting. Growing to its largest size in the far north.

Norway Spruce

1. Branchlet with partly opened cone, × 1/2.

2. Leaf, × 3.

3. Cross-sections of leaves, enlarged.

4. Cone-scale with seeds, × 1.

PINACEAE

Norway Spruce

Picea abies (L.) Karst. [Picea excelsa Link]

HABIT.—A tree 50-70 feet high, with a trunk diameter of 1-3 feet; forming a dense, conical, spire-topped crown of numerous, drooping branches which persist nearly to the ground.

LEAVES.—Spirally arranged along the twig; crowded; 3/4-1 inch long; rigid, curved, acute; lustrous, dark green. Persistent 5-7 years.

FLOWERS.—May; monoecious; the staminate ovoid to subglobose, long-stalked, reddish to yellowish, 3/4-1 inch long; the pistillate cylindrical, sessile, erect, 1-1/2-2 inches long.

FRUIT.—Autumn of first season; sessile, cylindrical cones 3-6 inches long, pendent from the tips of the uppermost branches; sterile scales very short, toothed; seeds red-brown, rough, 1/8 inch long, with long wings.

WINTER-BUDS.—Ovoid, acute, red-brown, not resinous, about 3/8 inch long.

BARK.—Twigs red- or orange-brown, smooth or corrugated; becoming thin and gray-brown on old trunks, slightly fissured, scaly.

WOOD.—Light, strong, tough, elastic, soft, fine-grained, white, with thick, indistinguishable sapwood.

NOTES.—Grows to a height of 120-150 feet in northern Europe and Asia. Perfectly hardy in Michigan. Easily transplanted. Adapts itself to a variety of soils and climates. Grows rapidly, but is short-lived in our country. Desirable for ornamental planting. Useful for shelter belts.

Balsam Fir

1. Winter branchlet, × 1.

2-3. Leaves, × 2.

4. Cross-section of leaf, enlarged.

5. Unopened cone, × 1.

6. Cone-scale with seeds, × 1.

PINACEAE

Balsam Fir

Abies balsamea (L.) Mill.

HABIT.—A slender tree 40-60 feet high, with a trunk diameter of 12-18 inches; branches in whorls of 4-6, forming a symmetrical, open crown widest at the base and tapering regularly upward.

LEAVES.—Scattered, spirally arranged in rows, on young trees extending from all sides of the branch, on old trees covering the upper side of the branch; narrowly linear, with apex acute or rounded; 1/2-1-1/4 inches long; lustrous, dark green above, pale beneath; sessile; aromatic. Persistent 8-10 years.

FLOWERS.—May; monoecious; the staminate oblong-cylindrical, yellow, 1/4 inch long, composed of yellow anthers (subtended by scales) spirally arranged upon a central axis; the pistillate oblong-cylindrical, 1 inch long, composed of orbicular, purple scales (subtended by yellow-green bracts) spirally arranged upon a central axis.

FRUIT.—Autumn of first season; oblong-cylindrical, erect, puberulous, dark purple cones, 2-4 inches long, about 1 inch thick; seeds 1/4 inch long, shorter than their light brown wings.

WINTER-BUDS.—Globose, orange-green, resinous, 1/8-1/4 inch in diameter.

BARK.—Twigs at first grayish and pubescent, becoming gray-brown and smooth; thin and smooth on young trunks, pale gray-brown and marked by swollen resin chambers; red-brown on old trunks and somewhat roughened by small, scaly plates.

WOOD.—Very light, soft, weak, coarse-grained, perishable, pale brown, with thick, lighter colored sapwood.

DISTRIBUTION.—Occasional in the southern half of the Lower Peninsula, frequent in the northern half; abundant in the Upper Peninsula.

HABITAT.—Prefers cool, moist, rich soil; low, swampy ground; well-drained hillsides.

NOTES.—Grows rapidly. Short-lived. Easily transplanted.

Hemlock

1. Fruiting branch viewed from beneath, × 1/2.

2. Leaf, × 3.

3. Cross-section of leaf, enlarged.

4. Branchlet with partly opened cone, × 1.

5. Cone-scale with seeds, × 3.

PINACEAE

Hemlock

Tsuga canadensis (L.) Carr.

HABIT.—A large tree 60-80 feet high, with a trunk 2-4 feet in diameter; forming a rather broad, open, somewhat irregular-pyramidal crown of slender, horizontal branches.

LEAVES.—Spirally arranged around the branch, but appearing 2-ranked by the twisting of their petioles; linear, flat, rounded at the apex; about 1/2 inch long; dark yellow-green and shining above, hoary beneath; short-petioled. Persistent about 3 years.

FLOWERS.—April-May; monoecious; the staminate axillary, short-stalked, light yellow, about 3/8 inch long, composed of subglobose clusters of stamens; the pistillate terminal, oblong, pale green, 1/8 inch long, the scales short, pinkish.

FRUIT.—Autumn of first season, gradually losing their seeds during the winter and falling the next spring; oblong-ovoid, acute, short-stalked, red-brown cones, about 3/4 inch long; seeds 1/8 inch long, with wings about twice as long.

WINTER-BUDS.—Ovoid, obtuse, red-brown, slightly puberulous, 1/16 inch long.

BARK.—Twigs at first pale brown and pubescent, becoming glabrous, gray-brown; thick, red-brown or gray on the trunk, deeply divided into narrow, rounded, scaly ridges.

WOOD.—Light, soft, weak, brittle, coarse- and crooked-grained, not durable, ill-smelling, light red-brown, with thin, darker colored sapwood.

DISTRIBUTION.—Throughout the state, with the exception of the south-eastern portion; scarce on the east side of the state, more common on the west, becoming very abundant in Emmet County.

HABITAT.—Prefers well-drained uplands and slopes of ravines.

NOTES.—A favorite hedge plant. Useful for ornamental planting in shady situations.

Arborvitae. White Cedar

1. Fruiting branchlet, × 1.

2. Tip of branchlet, enlarged.

3. Cone-scale with seeds, × 3.

PINACEAE

Arborvitae. White Cedar

Thuja occidentalis L.

HABIT.—A tree 40-50 feet high, with a short, often buttressed trunk 1-2 feet in diameter, often divided into 2-3 secondary stems; forming a rather dense, wide-based, pyramidal crown.

LEAVES.—Opposite, 4-ranked, scale-like, appressed; ovate, obtuse or pointed, keeled in the side pairs, flat in the others; 1/8-1/4 inch long; yellow-green, often becoming brown in winter; strongly aromatic when crushed. Persistent 1-2 years.

FLOWERS.—April-May; usually monoecious; the staminate minute, globose, yellow, composed of 4-6 stamens arranged oppositely on a short axis; the pistillate small, oblong, reddish, composed of 8-12 scales arranged oppositely on a short axis.

FRUIT.—Early autumn of first season, but persistent on the branch through the winter; erect, short-stalked, oblong-ovoid, pale brown cones, about 1/2 inch long, composed of 8-12 loose scales; seeds 1/8 inch long, ovate, acute, winged.

WINTER-BUDS.—Naked, minute.

BARK.—Twigs yellow-green, becoming light red, finally smooth, lustrous, dark orange-brown; thin, light red-brown on the trunk, slightly furrowed or deciduous in ragged strips.

WOOD.—Light, soft, brittle, rather coarse-grained, durable, fragrant, pale yellow-brown, with thin, whitish sapwood.

DISTRIBUTION.—Throughout the Upper Peninsula, Lower Peninsula as far south as Montcalm County.

HABITAT.—Prefers moist soil in low swamps and along river-banks.

NOTES.—Slow of growth. Tolerant of all soils and exposures. Especially useful for hedges or narrow evergreen screens.

Red Juniper. Red Cedar

1. Branchlet with awl-shaped leaves, × 1.

2. Tip of branchlet, showing awl-shaped leaves, enlarged.

3. Fruiting branchlet with scale-like leaves, × 1.

4. Tip of branchlet, showing scale-like leaves, enlarged.

PINACEAE

Red Juniper. Red Cedar

Juniperus virginiana L.

HABIT.—A medium-sized tree 30-40 feet high, with a trunk diameter of 1-2 feet; forming an irregular, pyramidal or rounded crown.

LEAVES.—Opposite, of two kinds: (1) sessile, scale-like, closely appressed, overlapping, 4-ranked, ovate, acute, 1/16 inch long, (2) sessile, awl-shaped, loosely arranged, 1/4-1/2 inch long. Persistent 5-6 years.

FLOWERS.—May; usually dioecious; minute; the staminate oblong-ovoid, composed of 4-6 shield-like scales, each bearing 4-5 yellow, globose pollen sacs; the pistillate ovoid, composed of about 3 pairs of flesh, bluish scales, united at the base and bearing 2 ovules.

FRUIT.—Autumn of first or second season; subglobose, berry-like strobile, about 1/4 inch in diameter, dark blue and glaucous; flesh sweet and resinous; seeds 2-3.

WINTER-BUDS.—Naked, minute.

BARK.—Twigs greenish to red-brown and smooth; thin, light red-brown on the trunk, exfoliating lengthwise into long, narrow, persistent strips, exposing the smooth, brown inner bark.

WOOD.—Light, soft, close-grained, brittle, weak, durable, very fragrant, dull red, with thin, whitish sapwood.

DISTRIBUTION.—Occurs sparingly throughout the state; most abundant in the southern portion.

HABITAT.—Prefers loamy soil on sunny slopes; dry, rocky hills; also borders of lakes and streams, peaty swamps.

NOTES.—Slow of growth. Long-lived. Should be transplanted with ball of earth. Tolerant of varied soils and situations.

SALICACEAE

SUMMER KEY TO THE SPECIES OF SALIX[D]

WINTER KEY TO THE SPECIES OF SALIX

The classification of the Willows is a task for the specialist, even when leaves and both staminate and pistillate flowers are obtainable. It is impractible for the novice to attempt the determination of species of Salix with winter characters alone. Consequently the usual winter key is omitted.

SALICACEAE

Willow

Salix (Tourn.) L.

The genus Salix is represented in Michigan by thirty or more distinct species, and there are many more hybrids. The majority of these are shrubs, only a few becoming truly arborescent. Because of the similarity of their botanical characters, the frequency with which they hybridize, and the facility with which they respond to their environment only an expert is competent to identify the species so abundant along our water courses and on the banks of our lakes and swamps. The scope of this work being necessarily limited, it has been deemed best to describe but two of our native willows and two of our foreign neighbors which are frequently planted.

Black Willow

1. Winter twig, × 1.

2. Portion of twig, enlarged.

3. Leaf, × 1.

4. Staminate flowering branchlet, × 1.

5. Staminate flower, enlarged.

6. Pistillate flowering branchlet, × 1.

7. Pistillate flower, enlarged.

8. Fruiting branchlet, × 1.

SALICACEAE

Black Willow

Salix nigra Marsh.

HABIT.—A tree 30-50 feet high, with a short trunk, 1-2 feet in diameter; stout, spreading branches form a broad, rather irregular, open crown. Often a shrub.

LEAVES.—Alternate, simple, 3-6 inches long, 1/4-3/4 inch broad; lanceolate, very long-pointed, often curved at the tip; finely serrate; thin; bright green and rather lustrous above, paler and often hairy beneath; petioles very short, more or less pubescent.

FLOWERS.—April-May, with the leaves; dioecious; borne in crowded, slender, hairy catkins, 1-3 inches long; calyx 0; corolla 0; scales yellow, villous, stamens 3-6; ovary ovoid-conical, short-stalked, with stigmas nearly sessile.

FRUIT.—June; ovoid-conical capsule, 1/8 inch long, containing many minute seeds which are furnished with long, silky, white hairs.

WINTER-BUDS.—Terminal bud absent; lateral buds narrow-conical, acute, lustrous, red-brown, 1/8 inch long.

BARK.—Twigs glabrous or pubescent, bright red-brown, becoming darker with age; thick, dark brown or nearly black on old trunks, deeply divided into broad, flat ridges, often becoming shaggy.

WOOD.—Light, soft, weak, close-grained, light red-brown, with thin, whitish sapwood.

DISTRIBUTION.—Common throughout the state.

HABITAT.—Banks of streams and lake-shores.

NOTES.—Branchlets very brittle at the base, and these, broken off by the wind, are carried down stream, often catching in the muddy banks and there taking root.

Almondleaf Willow

1. Winter twig, × 1.

2. Lateral bud, enlarged.

3. Leaf, × 1.

4. Staminate flowering branchlet, × 1/2.

5. Staminate flower, enlarged.

6. Pistillate flowering branchlet, × 1/2.

7. Pistillate flower, enlarged.

8. Fruiting branchlet, × 1/2.

SALICACEAE

Almondleaf Willow

Salix amygdaloides Anders.

HABIT.—A tree 30-40 feet high, with a straight, columnar trunk 1-2 feet in diameter; straight, ascending branches form a rather narrow, rounded crown.

LEAVES.—Alternate, simple, 2-6 inches long, 3/4-1-1/4 inches broad; lanceolate to ovate-lanceolate, long-pointed; finely serrate; thin and firm; light green and shining above, pale and glaucous beneath; petioles slender, 1/2-3/4 inch long.

FLOWERS.—April, with the leaves; dioecious; borne in crowded, slender, pubescent catkins 2-3 inches long; calyx 0; corolla 0; scales yellow, villous both sides; stamens 5-9; ovary oblong-conical, with stigmas nearly sessile.

FRUIT.—May; 1-celled, globose-conical capsule, 1/4 inch long, containing many minute seeds which are furnished with long, silky, white hairs.

WINTER-BUDS.—Terminal bud absent; lateral buds broadly ovoid, gibbous, lustrous, dark brown, 1/8 inch long.

BARK.—Twigs glabrous, lustrous, dark orange or red-brown becoming darker orange-brown; thick and brown on old trunks, irregularly fissured into flat, connected ridges.

WOOD.—Light, soft, weak, close-grained, light brown, with thick, whitish sapwood.

DISTRIBUTION.—Common throughout the state.

HABITAT.—Banks of streams.

NOTES.—Hybridizes freely with other willows, making its identification difficult.

Crack Willow. Brittle Willow

1. Winter twig, × 1.

2. Portion of twig, enlarged.

3. Leaf, × 1.

4. Staminate flowering branchlet, × 1/2.

5. Staminate flower, enlarged.

6. Pistillate flowering branchlet, × 1/2.

7. Pistillate flower, enlarged.

8. Fruiting branchlet, × 1/2.

SALICACEAE

Crack Willow. Brittle Willow

Salix fragilis L.

HABIT.—A tree 50-60 feet high, with a short, stout trunk 3-4 feet in diameter; stout, spreading branches form a broad, open crown.

LEAVES.—Alternate, simple, 3-6 inches long, 1/2-1-1/2 inches broad; lanceolate, long-pointed; finely glandular-serrate; thin and firm; lustrous, dark green above, paler beneath, glabrous both sides; petioles short, stout, with 2 glands at the junction of blade and petiole.

FLOWERS.—April-May, with the leaves; dioecious; borne in slender, pubescent catkins 1-3 inches long; calyx 0; corolla 0; scales blunt, somewhat pubescent; stamens usually 2; ovary abortive, with stigmas nearly sessile. Staminate trees rare.

FRUIT.—April-May; 1-celled, long-conical, short-stalked capsule, about 1/4 inch long, containing many minute seeds which are furnished with long, silky, white hairs.

WINTER-BUDS.—Terminal bud absent; lateral buds long-conical, pointed, glabrous, bright red-brown, about 1/4 inch long.

BARK.—Twigs pubescent, yellow-green, often reddish, becoming glabrous, lustrous, brown; thick, gray on the trunk, smooth in young trees, very rough, irregularly scaly-ridged in old trees.

WOOD.—Light, soft, tough, close-grained, red-brown, with thick, whitish sapwood.

NOTES.—A native of Europe and Asia, where it is a valuable timber tree. Hardy throughout the state and of very rapid growth. Thrives in rich, damp soil. Easily grown from cuttings. The twigs are very brittle at the base and are easily broken by the wind, hence the name Brittle Willow.

Weeping Willow. Napoleon’s Willow

1. Winter twig, × 1.

2. Portion of twig, enlarged.

3. Leaf, × 1.

4. Pistillate flowering branchlet, × 1/2.

5. Pistillate flower, enlarged.

6. Fruiting branchlet, × 1/2.

SALICACEAE

Weeping Willow. Napoleon’s Willow

Salix babylonica L.

HABIT.—A tree 40-50 feet high, with a short, stout trunk 3-4 feet in diameter; the long, slender branchlets, often many feet in length, droop in graceful festoons, giving to the tree a weeping habit.

LEAVES.—Alternate, simple, 3-7 inches long, 1/4-1/2 inch broad; linear to linear-lanceolate, long-pointed; finely sharp-serrate; thin and firm; glabrous, dark green above, paler beneath; petioles 1/2 inch or less in length, glandular above, often hairy.

FLOWERS.—April-May, with the leaves; dioecious; borne in slender, nearly glabrous catkins 1-2 inches long; calyx 0; corolla 0; scales ovate-lanceolate, slightly hairy; ovary ovoid-conical, very short-stalked, with stigmas longer than the style. Staminate trees apparently do not occur in the United States.

FRUIT.—May-June; 1-celled, narrow-ovoid, sessile capsule, about 3/16 inch long, containing many minute seeds which are furnished with long, silky, white hairs.

WINTER-BUDS.—Terminal bud absent; lateral buds narrow-conical, sharp-pointed, somewhat flattened, brownish, 1/8-1/4 inch long.

BARK.—Twigs glabrous, olive-green; thick and gray on old trunks, rather smooth, or irregularly fissured into shallow, firm ridges.

WOOD.—Light, soft, weak, close-grained, light brown, with thick, whitish sapwood.

NOTES.—A native of Europe and Asia. Often grown in cemeteries. Easily propagated by cuttings. Rapid of growth in rich, damp soil. Sometimes winter-killed because the wood is not ripened.

SUMMER KEY TO THE SPECIES OF POPULUS

WINTER KEY TO THE SPECIES OF POPULUS

White Poplar

1. Winter twig, × 1.

2. Portion of twig, enlarged.

3. Leaf, × 2.

4. Staminate flowering branchlet, × 1/2.

5. Staminate flower, enlarged.

6. Pistillate flowering branchlet, × 1/2.

7. Pistillate flower, enlarged.

8. Fruit, × 1/2.

SALICACEAE

White Poplar

Populus alba L.

HABIT.—A large tree 60-80 feet high, with a trunk diameter of 2-4 feet, forming a large, spreading, rounded or irregular crown of large, crooked branches and sparse, stout branchlets.

LEAVES.—Alternate, simple, 2-4 inches long and almost as broad; broadly ovate to suborbicular; irregularly toothed, sinuate, or sometimes 3-5-lobed; glabrous, dark green above, white-tomentose to glabrous beneath; petioles long, slender, flattened, tomentose.

FLOWERS.—April-May, before the leaves; dioecious; the staminate catkins thick, cylindrical, 2-4 inches long; the pistillate catkins slender, 1-2 inches long; calyx 0; corolla 0; stamens 6-16, with purple anthers; stigmas 2, branched, yellow.

FRUIT.—May-June; ovoid, 2-valved capsules, 1/8-1/4 inch long, borne in drooping catkins 2-4 inches long; seeds light brown, surrounded by long, white hairs.

WINTER-BUDS.—Ovoid, pointed, not viscid, downy, about 1/4 inch long.

BARK.—Twigs greenish, covered with a white down, becoming greenish gray and marked with darker blotches; dark gray and fissured at the base of old trunks.

WOOD.—Light, soft, weak, difficult to split, reddish yellow, with thick, whitish sapwood.

NOTES.—A native of Europe and Asia. Hardy in Michigan. Grows rapidly in good soils; thrives in poor soils and exposed situations. Roots deep, producing numerous suckers for a considerable distance from the tree.

Aspen

1. Winter twig, × 2.

2. Leaf, × 1.

3. Staminate flowering branchlet, × 1/2.

4. Staminate flower, enlarged.

5. Pistillate flowering branchlet, × 1/2.

6. Pistillate flower, enlarged.

7. Fruit, × 1/2.

SALICACEAE

Aspen

Populus tremuloides Michx.

HABIT.—A small, slender tree generally 35-45 feet high, with a trunk diameter of 8-15 inches; forming a loose, rounded crown of slender branches.

LEAVES.—Alternate, simple, 1-1/2-2-1/2 inches long and broad; broadly ovate to suborbicular; finely serrate; thin and firm; lustrous, dark green above, dull and pale beneath; petioles slender, laterally compressed. Tremulous with the slightest breeze.

FLOWERS.—April, before the leaves; dioecious; the staminate catkins 1-1/2-3 inches long, the pistillate at first about the same length, gradually elongating; calyx 0; corolla 0; stamens 6-12; stigmas 2, 2-lobed, red.

FRUIT.—May-June; 2-valved, oblong-cylindrical, short-pedicelled capsules 1/4 inch long; seeds light brown, white-hairy.

WINTER-BUDS.—Terminal bud about 1/4 inch long, narrow-conical, acute, red-brown, lustrous; lateral buds often appressed.

BARK.—Twigs very lustrous, red-brown, becoming grayish and roughened by the elevated leaf-scars; thin, yellowish or greenish and smooth on the trunk, often roughened with darker, horizontal bands or wart-like excrescences, becoming thick and fissured, almost black at the base of old trunks.

WOOD.—Light, soft, weak, close-grained, not durable, light brown, with thin, whitish sapwood.

DISTRIBUTION.—Common throughout the state, but most abundant in the Upper Peninsula.

HABITAT.—Prefers moist, sandy soil and gravelly hillsides.

NOTES.—One of the first trees to cover burned-over lands. Grows rapidly. Usually short-lived. Propagated from seed or cuttings.

Largetooth Aspen

1. Winter twig, × 2.

2. Leaf, × 1.

3. Staminate flowering branchlet, × 1/2.

4. Staminate flower, enlarged.

5. Pistillate flowering branchlet, × 1/2.

6. Pistillate flower, enlarged.

7. Fruit, × 1/2.

SALICACEAE

Largetooth Aspen

Populus grandidentata Michx.

HABIT.—A medium-sized tree 30-50 feet high, with a slender trunk 12-20 inches in diameter; forming a loose, oval or rounded crown of slender, spreading branches and coarse spray.

LEAVES.—Alternate, simple, 3-5 inches long, two-thirds as broad; orbicular-ovate; coarsely and irregularly sinuate-toothed; thin and firm; dark green above, paler beneath, glabrous both sides; petioles long, slender, laterally compressed.

FLOWERS.—April, before the leaves; dioecious; the staminate in short-stalked catkins 1-3 inches long; the pistillate in loose-flowered, long-stalked catkins at first about the same length, but gradually elongating; calyx 0; corolla 0; stamens 6-12, with red anthers; stigmas 2, 2-lobed, red.

FRUIT.—May; 2-valved, conical, acute, hairy capsules 1/8 inch long, borne in drooping catkins 4-6 inches long; seeds minute, dark brown, hairy.

WINTER-BUDS.—Terminal bud 1/8 inch long, ovoid to conical, acute, light chestnut, puberulous, dusty-looking.

BARK.—Twigs greenish gray and at first hoary-tomentose, becoming lustrous, orange or red-brown and finally greenish gray; thick, dark red-brown or blackish at the base of old trunks, irregularly fissured, with broad, flat ridges.

WOOD.—Light, soft, weak, close-grained, light brown, with thin, whitish sapwood.

DISTRIBUTION.—A common tree in the northern portions of the Lower Peninsula, but rare in the Upper Peninsula.

HABITAT.—Prefers rich, moist, sandy soil; borders of swamps; river-banks; hillsides.

NOTES.—Grows rapidly in many soils. Easily transplanted. Short-lived. Useful for temporary effect. Propagated from seed or cuttings.

Balm of Gilead. Balsam

1. Winter twig, × 1.

2. Leaf, × 3/4.

3. Staminate flowering branchlet, × 1/2.

4. Staminate flower, enlarged.

5. Catkin of pistillate flower, × 1/2.

6. Pistillate flower, enlarged.

7. Fruit, × 1/2.

SALICACEAE

Balm of Gilead. Balsam

Populus balsamifera L.

HABIT.—A tree 60-75 feet high, with a trunk diameter of 1-3 feet; forming a rather narrow, open, pyramidal crown of few, slender, horizontal branches.

LEAVES.—Alternate, simple, 3-6 inches long, about one-half as broad; ovate to ovate-lanceolate; finely crenate-serrate; thin and firm; lustrous, dark green above, paler beneath; petioles 1-1/2 inches long, slender, terete, smooth.

FLOWERS.—April, before the leaves; dioecious; the staminate in long-stalked catkins 3-4 inches long; the pistillate in loose-flowered, long-stalked catkins 4-5 inches long; calyx 0; corolla 0; stamens 20-30, with bright red anthers; ovary short-stalked; stigmas 2, wavy-margined.

FRUIT.—May-June; 2-valved, ovoid, short-pedicelled capsules 1/4 inch long, borne in drooping catkins 4-6 inches long; seeds light brown, hairy.

WINTER-BUDS.—Terminal bud about 1 inch long, ovoid, long-pointed, brownish, resin-coated, sticky, fragrant.

BARK.—Twigs red-brown, becoming dark orange, finally green-gray; thick, grayish on old trunks, and shallowly fissured into broad, rounded ridges, often roughened by dark excrescences.

WOOD.—Light, soft, weak, close-grained, light red-brown, with thick, nearly white sapwood.

DISTRIBUTION.—Occurs throughout the entire state, but is more abundant and of greater size in the northern portions.

HABITAT.—Prefers river bottom-lands and borders of swamps.

NOTES.—Rapid in growth. Spreads from the roots. Most useful for shelter belts. Easily transplanted. Propagated from cuttings.

Hairy Balm of Gilead. Balsam

1. Winter twig, × 1.

2. Leaf, × 1/2.

3. Staminate flowering branchlet, × 1/2.

4. Staminate flower, enlarged.

5. Pistillate flowering branchlet, × 1/2.

6. Pistillate flower, enlarged.

7. Fruit, × 1/2.

SALICACEAE

Hairy Balm of Gilead. Balsam

Populus candicans Ait. [Populus balsamifera candicans (Ait.) Gray]

HABIT.—A tree 50-70 feet high, with a trunk diameter of 1-3 feet; more spreading branches than in P. balsamifera, forming a broader and more open crown.

LEAVES.—Resemble those of P. balsamifera, but more broadly heart-shaped and more coarsely serrate; more or less pubescent when young; petioles pubescent.

FLOWERS.—Similar to those of P. balsamifera.

FRUIT.—Similar to that of P. balsamifera.

WINTER-BUDS.—Terminal bud about 1 inch long, ovoid, long-pointed, dark red-brown, resinous throughout, viscid, very aromatic.

BARK.—Twigs reddish or olive-green, with occasional longitudinal gray lines, covered with a fragrant, gummy secretion, becoming gray-green; dark gray, rough, irregularly striate and firm on old trunks.

WOOD.—Resembles that of P. balsamifera, but is somewhat heavier.

DISTRIBUTION.—Indigenous to the northern portions of the state, but often cultivated and occasionally escaping in the southern portion.

HABITAT.—In a great variety of soils and situations.

NOTES.—Grows rapidly in all soils and situations. Suckers readily from the roots. Propagated from cuttings.

Cottonwood

1. Winter twig, × 1.

2. Leaf, × 1/2.

3. Staminate flowering branchlet, × 1/2.

4. Staminate flower, enlarged.

5. Pistillate catkin, × 1/2.

6. Pistillate flower, enlarged.

7. Fruit, × 1/2.

SALICACEAE

Cottonwood

Populus deltoides Marsh. [Populus monilifera Ait.]

HABIT.—A stately tree attaining a height of 70-90 feet and a trunk diameter of 3-5 feet; forming a spreading, open, symmetrical crown of massive, horizontal branches and stout, more or less angled branchlets.

LEAVES.—Alternate, simple, 3-6 inches long, nearly as broad; broadly deltoid-ovate; coarsely crenate-serrate above the entire base; thick and firm; lustrous, dark green above, paler beneath; petioles 2-3 inches long, slender, compressed laterally.

FLOWERS.—April-May, before the leaves; dioecious; the staminate in short-stalked, densely-flowered catkins 3-4 inches long; the pistillate in short-stalked, few-flowered catkins elongating to 6-8 inches; calyx 0; corolla 0; stamens very numerous, with red anthers; stigmas 3-4, spreading.

FRUIT.—May; 2-4-valved, short-stalked capsules, borne in drooping catkins 5-10 inches long; seeds light brown, densely cottony.

WINTER-BUDS.—Terminal bud 1/2 inch long, conical, acute, very resinous, shining, brownish.

BARK.—Twigs and young stems smooth, yellow-green; old trunks ashy gray, deeply divided into straight furrows with broad, rounded ridges.

WOOD.—Light, soft, weak, close-grained, dark brown, with thick, whitish sapwood; warps badly and is difficult to season.

DISTRIBUTION.—Entire Michigan; rare in the northern portions.

HABITAT.—Prefers rich, moist soil; river-banks; river-bottoms; lake-shores; grows well in drier situations.

NOTES.—Rapid of growth, consequently an excellent tree for immediate effect. Propagated from cuttings.

Lombardy Poplar

1. Winter twig, × 1.

2. Portion of twig, enlarged.

3. Leaf, × 3/4.

4. Staminate flowering branchlet, × 1/2.

5. Staminate flower, enlarged.

SALICACEAE

Lombardy Poplar

Populus nigra italica DuRoi [Populus fastigiata Desf.] [Populus dilatata Ait.]

HABIT.—A tree 75-100 feet high, with a short, ridged and buttressed trunk 4-6 feet in diameter and a narrow, spire-like crown of erect branches.

LEAVES.—Alternate, simple, 2-4 inches long, and usually somewhat broader than long; broad-deltoid, abruptly acuminate; finely but bluntly crenate-serrate; thick and firm; dark green and shining above, lighter and more or less lustrous beneath; petioles slender, laterally compressed, 1-2 inches long.

FLOWERS.—April-May, before the leaves; dioecious; the staminate in sessile, dark red, cylindrical catkins about 3 inches long; the pistillate not present in the United States; calyx 0; corolla 0; stamens about 8, with white filaments and purple anthers.

FRUIT.—Not formed in the United States in the absence of pistillate flowers.

WINTER-BUDS.—Terminal bud conical, slightly angled, taper-pointed, glutinous, about 3/8 inch long; lateral buds smaller, appressed.

BARK.—Twigs glabrous, shining yellow, becoming gray; thick and gray-brown on old trunks, deeply and irregularly furrowed.

WOOD.—Light, soft, easily worked, not liable to splinter, weak, not durable, light red-brown, with thick, nearly white sapwood.

NOTES.—Thought to be a native of Afghanistan. Very rapid in growth. Short-lived. Spreads by means of suckers and fallen branches. Useful for ornamental purposes. Because of crowding the limbs die early, which remain and cause the tree to look unsightly.

JUGLANDACEAE

SUMMER KEY TO THE SPECIES OF JUGLANS

WINTER KEY TO THE SPECIES OF JUGLANS

Butternut

1. Winter twig, × 1.

2. Leaf, × 1/6

3. Leaflet, × 1/2

4. Flowering branchlet, × 1/2.

5. Staminate flower, enlarged.

6. Pistillate flower, enlarged.

7. Fruit, × 1/2.

JUGLANDACEAE

Butternut

Juglans cinerea L.

HABIT.—A medium-sized tree 40-60 feet high, with a short trunk 2-3 feet in diameter; forming a wide-spreading crown of large, horizontal branches and stout, stiff branchlets.

LEAVES.—Alternate, compound, 15-30 inches long. Leaflets 11-17, 2-4 inches long and one-half as broad; sessile, except the terminal; oblong-lanceolate; finely serrate; thin; yellow-green and rugose above, pale and soft-pubescent beneath. Petioles stout, hairy.

FLOWERS.—May, with the leaves; monoecious; the staminate in cylindrical, greenish, drooping catkins 3-5 inches long; calyx 6-lobed, borne on a hairy bract; corolla 0; stamens 8-12, with brown anthers; the pistillate solitary or several on a common peduncle, about 1/3 inch long, their bracts and bractlets sticky-hairy; calyx 4-lobed, hairy; corolla 0; styles 2; stigmas 2, fringed, spreading, bright red.

FRUIT.—October; about 2-1/2 inches long, cylindrical, pointed, greenish, sticky-downy, solitary or borne in drooping clusters of 3-5; nuts with rough shells, inclosing a sweet, but oily kernel; edible.

WINTER-BUDS.—Terminal bud 1/2-3/4 inch long, oblong-conical, obliquely blunt, somewhat flattened, brownish, pubescent.

BARK.—Twigs orange-brown or bright green, rusty-pubescent, becoming smooth and light gray; gray and smoothish on young trunks, becoming brown on old trunks, narrow-ridged, with wide furrows.

WOOD.—Light, soft, weak, coarse-grained, light brown, with thin, lighter colored sapwood.

DISTRIBUTION.—Of common occurrence in the southern half of the Lower Peninsula.

HABITAT.—Prefers low, rich woods; river-banks; low hillsides.

NOTES.—Leaves appear late and fall early. Pith chambered, chocolate-brown. Large trees usually unsound. Not easily transplanted.

Black Walnut

1. Winter twig, × 1.

2. Leaf, × 1/6.

3. Leaflet, × 1/2.

4. Flowering branchlet, × 1/2.

5. Staminate flower, back view, enlarged.

6. Pistillate flower, enlarged.

7. Fruit, × 1/2.

JUGLANDACEAE

Black Walnut

Juglans nigra L.

HABIT.—A large tree 60-80 feet high, with a massive trunk 2-5 feet in diameter; forming an open, capacious crown of heavy branches and coarse branchlets.

LEAVES.—Alternate, compound, 1-2 feet long. Leaflets 13-23, the terminal often lacking, 2-4 inches long and one-half as broad; sessile; ovate-lanceolate, taper-pointed; sharp-serrate; thin; yellow-green and glabrous above, lighter and soft-pubescent beneath. Petioles stout, pubescent. Foliage aromatic when bruised.

FLOWERS.—May, with the leaves; monoecious; the staminate in cylindrical, greenish, drooping catkins 3-5 inches long; calyx 6-lobed, borne on a hairy bract; corolla 0; stamens numerous, with purple anthers; the pistillate solitary or several on a common peduncle, about 1/4 inch long, their bracts and bractlets hairy; calyx 4-lobed, pubescent; corolla 0; styles and stigmas 2.

FRUIT.—October; globose, 1-1/2-2 inches in diameter, smooth, not viscid; solitary or borne in clusters of 2-3; nuts with irregularly furrowed shell, inclosing a sweet, edible kernel.

WINTER-BUDS.—Terminal bud 1/3 inch long, ovoid, obliquely blunt, slightly flattened, silky-tomentose.

BARK.—Twigs brownish and hairy, becoming darker and smooth; thick, brownish or blackish on the trunk and deeply furrowed by broad, rounded ridges.

WOOD.—Heavy, hard, strong, close-grained, very durable in contact with the soil, rich dark brown, with thin, lighter colored sapwood.

DISTRIBUTION.—Lower Peninsula as far north as Bay City, but more abundant in the southern portion of its range.

HABITAT.—Prefers rich bottom-lands and fertile hillsides.

NOTES.—Leaves appear late and fall early. Fruit very aromatic. Pith chambered, cream colored. The juices from the husk stain the hands brown. Not easily transplanted. Often infested with caterpillars.

SUMMER KEY TO THE SPECIES OF CARYA

WINTER KEY TO THE SPECIES OF CARYA

Shagbark Hickory. Shellbark Hickory

1. Winter twig, × 1.

2. Portion of twig, enlarged.

3. Leaf, × 1/3.

4. Flowering branchlet, × 1/2.

5. Staminate flower, enlarged.

6. Pistillate flower, enlarged.

7. Fruit, × 1/2.

JUGLANDACEAE

Shagbark Hickory. Shellbark Hickory

Carya ovata (Mill.) K. Koch [Hicoria ovata (Mill.) Britt.] [Carya alba Nutt.]

HABIT.—A tree 60-80 feet high, with a slender, columnar trunk 1-2 feet in diameter; forming a narrow, somewhat open crown of stout, slightly spreading limbs and stout branchlets.

LEAVES.—Alternate, compound, 8-14 inches long. Leaflets usually 5, the upper 5-7 inches long and 2-3 inches broad; sessile, except the terminal; obovate to oblong-lanceolate; finely serrate; thick and firm; glabrous, dark green above, paler beneath and glabrous or puberulous. Petioles stout, smooth or hairy. Foliage fragrant when crushed.

FLOWERS.—May, after the leaves; monoecious; the staminate hairy, greenish, in pendulous, ternate catkins 4-5 inches long, on a common peduncle about 1 inch long; scales 3-parted, bristle-tipped; stamens 4, with bearded, yellow anthers; the pistillate in 2-5-flowered spikes, 1/3 inch long, brown-tomentose; calyx 4-lobed, hairy; corolla 0; stigmas 2, large, fringed.

FRUIT.—October; globular, 1-2 inches long, with thick husk separating completely; nut usually 4-ridged, with thick shell and large, sweet, edible kernel.

WINTER-BUDS.—Terminal bud 1/2-3/4 inch long, broadly ovoid, obtuse, dark brown, pale-tomentose or nearly glabrous.

BARK.—Twigs brownish, more or less downy, becoming smooth and grayish; thick and grayish on old trunks, separating into thick strips 1-3 feet long, free at one or both ends, giving a characteristic shaggy appearance.

WOOD.—Heavy, very hard and strong, tough, close-grained, elastic, light brown, with thin, whitish sapwood.

DISTRIBUTION.—Common in the Lower Peninsula as far north as Roscommon County.

HABITAT.—Prefers light, well-drained, loamy soil; low hillsides; river-banks.

NOTES.—Hardy throughout its range. Moderately rapid in growth. Difficult to transplant.

Shellbark Hickory. King Nut

1. Winter twig, × 1/2.

2. Leaf, × 1/4.

3. Flowering branchlet, × 1/2.

4. Staminate flower, enlarged.

5. Pistillate flower, enlarged.

6. Fruit, × 1/2.

JUGLANDACEAE

Shellbark Hickory. King Nut

Carya laciniosa (Michx. f.) Loud. [Hicoria laciniosa (Michx. f.) Sarg.] [Carya sulcata Nutt.]

HABIT.—A tree 60-80 feet high, with a tall, slender trunk 2-3 feet in diameter; forming a narrow, oblong crown of small, spreading branches.

LEAVES.—Alternate, compound, 1-2 feet long. Leaflets usually 7, the upper 5-9 inches long, 3-5 inches broad, larger than the lowest pair; sessile or short-stalked; oblong-lanceolate to obovate, taper-pointed; finely serrate; thick and firm; lustrous, dark green above, paler and soft-pubescent beneath. Petioles stout, glabrous or pubescent, often persistent on the branches during the winter. Foliage fragrant when crushed.

FLOWERS.—May, after the leaves; monoecious; the staminate in pendulous, ternate catkins 5-8 inches long, slender, yellow-green, on common peduncles 1 inch long; scales 3-lobed, tomentose; stamens 4, with yellow, hairy anthers; the pistillate in crowded, 2-5-flowered spikes, tomentose; calyx 3-toothed, hairy; corolla 0; stigmas 2, light green.

FRUIT.—October; oblong to subglobose, 1-3/4-2-1/2 inches long, with very thick, woody husk, splitting to the base; nut 4-6-ridged, with thick, hard shell and large, sweet kernel.

WINTER-BUDS.—Terminal bud about 1 inch long, ovoid, obtuse, dark brown, puberulous.

BARK.—Twigs orange and more or less pubescent, becoming darker in the first winter, and finally grayish; on the trunk 1-2 inches thick, light gray, separating into broad, thick plates 3-4 feet long, persistent on the trunk for many years.

WOOD.—Heavy, very hard, strong, tough, close-grained, very elastic, dark brown, with thin, whitish sapwood.

DISTRIBUTION.—Occurs in the southern portion of the Lower Peninsula, but is rather a rare tree.

HABITAT.—Prefers deep, rich bottom-lands.

NOTES.—Rapid in growth. May be distinguished from other hickories by orange colored branchlets.

Mocker Nut Hickory

1. Winter twig, × 1.

2. Leaf, × 1/3.

3. Flowering branchlet, × 1/2.

4. Staminate flower, enlarged.

5. Pistillate flower, enlarged.

6. Fruit, × 1/2.

JUGLANDACEAE

Mocker Nut Hickory

Carya alba (L.) K. Koch [Hicoria alba (L.) Britt.] [Carya tomentosa Nutt.]

HABIT.—A tree 50-70 feet high, with a trunk diameter of 1-2-1/2 feet; forming a wide crown of strong, upright branches and stout branchlets.

LEAVES.—Alternate, compound, 8-12 inches long. Leaflets usually 5-7, sometimes 9, the upper 5-8 inches long, 3-4 inches broad; sessile, except the terminal; oblong- to obovate-lanceolate; minutely or sometimes coarsely serrate; thick and firm; lustrous, dark yellow-green above, paler and more or less pubescent beneath. Petioles pubescent. Foliage fragrant when crushed.

FLOWERS.—May, after the leaves; monoecious; the staminate in pendulous, ternate catkins 4-5 inches long, slender, green, hairy; scales 3-lobed, hairy; stamens 4-5, with red anthers; the pistillate in crowded, 2-5-flowered, tomentose spikes; calyx toothed, hairy; corolla 0; stigmas 2, hairy.

FRUIT.—October; globose to globose-oblong, 1-1/2-2 inches long, with thick husk splitting nearly to the base; nut 4-ridged, red-brown, with very thick, hard shell and small, sweet kernel.

WINTER-BUDS.—Terminal bud 1/2-3/4 inch long, broadly ovoid, red-brown, pilose; outermost scales fall in early autumn.

BARK.—Twigs at first brown-tomentose, becoming smooth and grayish; on the trunk thick, hard, grayish, slightly ridged by shallow, irregular fissures, becoming rugged on very old trunks.

WOOD.—Very heavy, hard, strong, tough, close-grained, elastic, dark brown, with thick, whitish sapwood.

DISTRIBUTION.—Southern Peninsula as far north as Grand Rapids and Flint. Infrequent.

HABITAT.—Prefers rich, well-drained soil, but grows well in various situations, if they are not too wet.

NOTES.—Hardy throughout its range. Difficult to transplant.

Small Pignut Hickory

1. Winter twig, × 1.

2. Leaf, × 1/3.

3. Flowering branchlet, × 1/2.

4. Staminate flower, enlarged.

5. Pistillate flower, enlarged.

6. Fruit, × 1.

JUGLANDACEAE

Small Pignut Hickory

Carya microcarpa Nutt. [Hicoria odorata (Marsh.) Sarg.] [Hicoria microcarpa (Nutt.) Britt.] [Hicoria glabra, v. odorata Sarg.]

HABIT.—A tree usually 50-70 feet high, with a trunk diameter of 1-3 feet; forming an oblong or sometimes rounded crown of slender, spreading branches.

LEAVES.—Alternate, compound, 8-12 inches long. Leaflets usually 5-7, the upper 3-6 inches long, 2-2-1/2 inches broad; sessile, except the terminal; oblong to ovate-lanceolate, long-pointed; sharply serrate; thick and firm; glabrous, dark yellow-green above, lighter beneath. Petioles long, glabrous. Foliage fragrant when crushed.

FLOWERS.—May, after the leaves; monoecious; the staminate in pendulous, ternate catkins 3-7 inches long, slender, greenish, glabrous; stamens 4, with orange anthers; the pistillate in 2-5-flowered spikes, 1/4 inch long; calyx 4-toothed, hairy; corolla 0; stigmas 2, yellow.

FRUIT.—September; subglobose or globose-oblong, less than 1 inch long, with thin husk splitting nearly to the base; nut obscurely 4-ridged, with thin shell and small, sweet kernel.

WINTER-BUDS.—1/4-1/2 inch long, dome-shaped, red-brown, smooth.

BARK.—Twigs greenish, long-hairy, becoming reddish and finally gray; thick, hard and grayish on the trunk, divided by shallow fissures into narrow plates, and more or less shaggy.

WOOD.—Heavy, hard, strong, tough, close-grained, elastic, dark brown, with thick, whitish sapwood.

DISTRIBUTION.—Confined to the most southern portions of the Lower Peninsula.

HABITAT.—Prefers well-drained slopes and hillsides.

NOTES.—Resembles C. glabra, but the nut is much smaller.

Pignut Hickory

1. Winter twig, × 1.

2. Leaf, × 1/4.

3. Flowering branchlet, × 1.

4. Staminate flower, enlarged.

5. Pistillate flower, enlarged.

6. Fruit, × 2/3.

JUGLANDACEAE

Pignut Hickory

Carya glabra (Mill.) Spach. [Hicoria glabra (Mill.) Britt.] [Carya porcina Nutt.]

HABIT.—A tree usually 50-65 feet high, with a trunk diameter of 1-3 feet; forming a low, rather narrow, open crown of slender, often contorted branches.

LEAVES.—Alternate, compound, 8-12 inches long. Leaflets usually 5-7, the upper 3-6 inches long, 2-2-1/2 inches broad; subsessile, except the terminal; oblong to obovate-lanceolate, taper-pointed; sharply serrate; thick and firm; glabrous, dark yellow-green above, paler beneath. Petioles long, slender, glabrous or pubescent. Foliage fragrant when crushed.

FLOWERS.—May, after the leaves; monoecious; the staminate in pendulous, ternate catkins 3-7 inches long, slender, yellow-green, tomentose; scales 3-lobed, nearly glabrous; stamens 4, with orange anthers; the pistillate in crowded, 2-5-flowered spikes, 1/4 inch long; calyx 4-toothed, hairy; corolla 0; stigmas 2, yellow.

FRUIT.—October; variable in size and shape, 1-1/2-2 inches long, with thin husk splitting half-way and sometimes nearly to the base; nut obscurely 4-ridged, with thin or thick, hard shell and small, sweet or slightly bitter kernel which is hard to remove.

WINTER-BUDS.—Terminal bud 1/4-1/2 inch long, dome-shaped, greenish or grayish, smooth or finely downy.

BARK.—Twigs greenish, nearly glabrous, becoming reddish, and finally grayish; thick, hard and grayish on the trunk, with a firm, close surface divided by small fissures and sometimes broken into plates.

WOOD.—Heavy, hard, very strong, tough, close-grained, elastic, dark brown, with thick, whitish sapwood.

DISTRIBUTION.—Occurs only in the extreme southern portion of the Lower Peninsula. Common within its range.

HABITAT.—Prefers deep, rich loam, but grows in any well-drained soil; dry ridges and hillsides.

NOTES.—Hardy and desirable for ornamental purposes. Difficult to transplant. Not adapted to street use.

Bitternut Hickory

1. Winter twig, × 1.

2. Leaf, × 1/3.

3. Flowering branchlet, × 1/2.

4. Staminate flower, enlarged.

5. Pistillate flower, enlarged.

6. Fruit, × 1.

JUGLANDACEAE

Bitternut Hickory

Carya cordiformis (Wang.) K. Koch [Hicoria minima (Marsh.) Britt.] [Carya amara Nutt.]

HABIT.—A tall, slender tree 50-75 feet high, with a trunk diameter of 1-2-1/2 feet; forming a broad crown of slender, stiff, upright branches, widest near the top.

LEAVES.—Alternate, compound, 6-10 inches long. Leaflets 5-11, the upper 4-6 inches long and one-fourth as broad; sessile, except the terminal; lanceolate to oblong-lanceolate, long-pointed; coarsely serrate; thin and firm; glabrous, bright green above, paler and more or less downy beneath. Petioles slender, hairy. Foliage fragrant when crushed.

FLOWERS.—May, after the leaves; monoecious; the staminate slightly pubescent, in pendulous, ternate catkins 3-4 inches long, on a common peduncle about 1 inch long; scales 3-lobed, hairy; stamens 4, with bearded, yellow anthers; the pistillate in 2-5-flowered spikes 1/2 inch long, scurfy-tomentose; calyx 4-lobed, pubescent; corolla 0; stigmas 2, greenish.

FRUIT.—October; obovate to globular, about 1 inch long, coated with yellow, scurfy pubescence, with very thin husk splitting half-way to the base, with sutures winged at the top; nut quite smooth, with thin shell and small, bitter kernel.

WINTER-BUDS.—Terminal bud about 3/4 inch long, long-pointed, flattish, granular-yellow; lateral buds more or less 4-angled.

BARK.—Twigs greenish and more or less downy, becoming brownish, and finally grayish; gray, close, smooth on the trunk, often reticulately ridged, but rarely broken into plates.

WOOD.—Heavy, very hard, strong, tough, close-grained, dark brown, with thick, lighter colored sapwood.

DISTRIBUTION.—Of common occurrence in the southern half of the Lower Peninsula.

HABITAT.—Prefers a rich, loamy or gravelly soil; low, wet woods; along the borders of streams; but also found on high, dry uplands.

NOTES.—Grows most rapidly of all the hickories, but is apt to show dead branches. Should be propagated from the seed, as it is not easily transplanted.

BETULACEAE

Hornbeam. Ironwood

1. Winter twig, × 1/2.

2. Portion of twig, enlarged.

3. Leaf, × 1/2.

4. Flowering branchlet, × 1/2.

5. Staminate flower, enlarged.

6. Pistillate flower, enlarged.

7. Fruit, × 1/2.

BETULACEAE

Hornbeam. Ironwood

Ostrya virginiana (Mill.) K. Koch

HABIT.—A small tree usually 20-30 feet high, with a trunk diameter of 8-12 inches; forming a broad, rounded crown of many long, slender branches and a slender, stiff spray.

LEAVES.—Alternate, simple, 3-5 inches long, about one-half as broad; oblong-ovate; sharply doubly serrate; thin and very tough; dull, dark green above, paler and more or less pubescent beneath; petioles short, slender, pubescent.

FLOWERS.—April-May, with the leaves; monoecious; the staminate in drooping, cylindrical catkins from wood of the previous season, usually in threes; stamens 3-14, crowded on a hairy torus; the pistillate in erect, lax catkins on the season’s shoots, usually in pairs, each flower inclosed in a hairy, sac-like involucre.

FRUIT.—September; strobiles, resembling clusters of hops, 1-2 inches long, borne on slender, hairy stems; nuts small and flat, inclosed by sac-like involucres.

WINTER-BUDS.—Terminal bud absent; lateral buds 1/8-1/4 inch long, ovoid, acute, red-brown.

BARK.—Twigs at first light green, becoming lustrous, red-brown, and finally dull dark brown; thin, gray-brown on the trunk, very narrowly and longitudinally ridged.

WOOD.—Heavy, very strong and hard, tough, close-grained, durable, light red-brown, with thick, whitish sapwood.

DISTRIBUTION.—Common throughout the entire state.

HABITAT.—Prefers dry, gravelly slopes and ridges.

NOTES.—Often grows in shade of other trees. Not easily transplanted. Rather slow of growth. Too small for street use.

Blue Beech. Water Beech

1. Winter twig, × 1.