B 3 fiM2 fllfl Agnc, -Forestry. Maia U £525 'JRotvi* Commonwealth of Pennsylvania DEPA: .VIENT OF FORESTRY BULLETIN NO. 11.— JUNE, 1914. Revised July, 1915. PENNSYLVANIA TREES BY J. S. ILLICK, A. B., F. E., Professor of Dendrology and Forest Management, Pennsylvania State Forest Academy. ISSUED BY DIRECTION OF THE COMMISSIONER OF FORESTRY HAKRTSBURG, PA.: . STANLEY RAY. STATE PRINTER 1915 3Di4-f f : •. .• : : ; : • •• t :• •./ . - Forestry - M»!a Librmry PENNSYLVANIA DEPARTMENT OF FORESTRY ROBERT S. CONKLIN, Commissioner of Forestry. IRVIN C. WILLIAMS, Deputy Commissioner of Forestry. STATE FORESTRY RESERVATION COMMISSION. ROBERT S. CONKLIN, President. SIMON B. ELLIOTT J. LINN HARRIS WM. P. STEVENSON. J. M. HOFFMAN. (3) w (4) LETTER OF TRANSMITTAL Hon. Robert S. Conklin, Commissioner of Forestry. Dear Sir: In compliance with your request I have the honor to transmit herewith the manuscript, plates, and photographs for a re- vised edition of the bulletin on "Pennsylvania Trees." It is the hope of the writer that the bulletin may aid in developing a fuller appre- ciation of the importance and value of our trees and forests. Yours respectfully, J. S. ILLICK. Mont Alto, Pa., July, 1915. (5) PREFACE Trees are among the commonest and most conspicuous objects of nature. The numerous products derived from them are very use- ful, often indispensable. In all ages trees and grasses have been the most important products of the soil. A dense and valuable tree growth covered originally almost the entire area of Pennsylvania. About 278 species of trees and shrubs are native to this State, of which number 125 are trees. The number of native representatives in the present forests is the same as in the original forest. While the number of representatives remains the same, yet one finds a marked difference in the degree of their abundance, and in their age, size, form, density, quality, value, and productivity. The original forest of the State was large, dense, and extremely productive. The present forests are small, open, and very unproductive. Each gener- ation of mankind has seen a smaller, more open, and less productive generation of forests. It is not a prophecy, but the statement of a fact, when we say that the source of our timber supply is becom- ing an acute and vital question. Fast-vanishing forests and ever- rising lumber prices are couriers of this fact. The Federal and some State Governments have already inaugurated policies to offset the present destructive tendency in our forests by starting constructive work. To date no state has made a greater advance in forestry than Pennsylvania. She has, however, just started on this useful mission. The men who are directing her forest policies are endeavoring to lay a substantial foundation upon which a stable superstructure may be reared. In order to accomplish this it is necessary to have the co-operation of the citizens of the State, especially the woodland owners and managers. Forestry needs the support of public senti- ment. No substantial and permanent advance is insured until our citizens' understand the fundamentals of forestry and can distin- guish the important timber trees from the inferior weed trees. It is hoped that the sphere of usefulness of this bulletin will not be limited to woodland owners and managers, but will extend to lay- men, students, and botanists. Part I is intended for the layman and the beginner of forestry. A careful perusal of this part will enable one to comprehend Part II more fully. The former comprises abstracts from the author's lec- (7) 8 tures on Elementary Forestry at the Pennsylvania State Forest Academy. Part II is essentially a manual of Pennsylvania trees. It com- prises a discussion on the identification of trees and a description of families, genera, and species, with accompanying keys. The descrip- tive material and keys are the outgrowth of typewritten outline notes prepared by the author and used for the past six years in con- nection with a course in dendrology given at the Pennsylvania State Forest Academy. Each species is described under about 14 headings. No special originality is claimed for the characteristics given under these headings. It is natural to expect that the descriptive mater- ial should correspond with that found in other texts. The author is glad to acknowledge his indebtedness to the many books of refer- ence which were frequently consulted to verify observations and to make the description clear and complete. The range of the species and the weight per cubic foot of their wood (air dry) have been drawn chiefly from Sargent's "The Silva of North America." The distribution in Pennsylvania was worked out in co-operation with the foresters connected with the Department of Forestry and a few others interested in the distribution of trees. Porter's "Flora of Pennsylvania" aided considerably in determining the distribution. Our present knowledge of the distribution of the different species in the State is by no means complete. Special efforts are being put forth to ascertain it more accurately. Future publications will con- tain the results of the present and prospective surveys covering the distribution of our trees. Any additions, suggestions, or corrections will be gladly received. The scientific names found in this bulletin are those used by the Department of Forestry, which follows the usage of the seventh edi- tion of Gray's New Manual of Botany. Shifting of individual plates from their proper systematic position was necessary in a few cases in order to place two companion plates on opposite sides of the same sheet. The photographic illustrations, 103 in number, are all original by the author, except Figs. 57 and 63 supplied by W. Gardiner Oonk- lin; Fig. 22 supplied by Guy Carleton Hawkins; Figs. 21 and 35 supplied by B. J. Gutknecht, and Figs. 1, 3, 4, 10, and 12 supplied by the Pennsylvania Department of Forestry. The drawings have been made by Miss Margaretta Washington, of Philadelphia, either from specimens supplied by the author or re- drawn and adapted from Sargent's "The Silva of North America" by special permission of the publisher, Houghton Mifflin Company. In making some of the drawings Schneider's "Dendrologische Winter- studien" and some of the reports of the Missouri Botanical Garden were consulted. 9 Grateful acknowledgment is tendered to Hon. Robert S. Conklin, Commissioner of Forestry, at whose suggestion the bulletin was started and under whose careful and constant direction it was de- veloped. Especial acknowledgment is due to Hon. I. C. Williams, Deputy Commissioner of Forestry, who read the entire manuscript, for his inspiration, many valuable suggestions and criticism. Thanks are due to George H. Wirt, Forest Inspector, and Prof. George A. Retan for their assistance and valuable suggestions. I take pleasure in expressing my gratification to all others who have in any way assisted in this publication, especially the students of the Pennsylvania State Forest Academy for their co-operation, and the graduates for their assistance in collecting data concerning the distribution of trees in this State. J. S. ILLTCK. (It) CONTENTS PART I. INTRODUCTORY. Page. The North American Forest , 13 Forests of Pennsylvania 13 The Forests and Forestry , . . . • 16 Forestry in Pennsylvania , 17 The Structure of the Forest, 19 The Establishment of the Forest, 21 The Development of the Forest, 23 The Protection of the Forest, 26 The Value of Forests , 28 The Value of Trees , 29 Deciduous and Evergreen Trees , 30 The Age of Trees, 31 The Form and Structure of Trees , '. 32 1. Form, 32 2. Bark, 34 3. Twigs, 36 4. Buds, 38 5. Leaves, 40 6 . Leaf-scars and Bundle-scars , 43 7 . Flowers , 44 8. Fruit, 46 9. Wood, , 49 PART II. MANUAL OF PENNSYLVANIA TREES. Identification of Species , 55 Names of Trees , , 55 Explanation of Terms and Headings, 56 How to Identify the Species and Use the Keys, 58 General Key to the Families , 63 Tabulation of Genera and Species , 65 Description of the Families, Genera, and Species, 67 Glossary , 220 Index, 225 (11) (12) f warn* or FORESTRY C0U.CGE Of A AGRtCUir - UNIVERSITY OF CAUFO.S,, , PART I. INTRODUCTORY. THE NORTH AMERICAN FOREST. There is good reason to believe that the major part of the habi- table earth was originally wooded. North America is no exception to this. The original forest extended from the Atlantic coast west to about the ninetieth meridan having only a few small openings like meadows and the tops of mountains. It also covered a large portion of the Rocky Mountain region and the Pacific slope. Estimates place the aggregate original area of the forests of North America at about 850,000,000 acres. This original area has been so reduced that not more than 550,000,000 acres remain at the present time and a large portion of this acreage is in a very unproductive condi- tion. The original forest of this country was vast in extent and com- posed of many and valuable species. The richness and variety of our tree growth may be in part attributed to the different climatic zones and variable physiographic features common to this country. So variable is our forest structure that at least five general forest regions may be recognized while often a local area may have its own peculiar forest type. Many of the trees in the original forest attained a great age and enormous size. They yielded a vast amount of valuable products, a source of great wealth, which has been supplying the raw material for one of our most important industries. Nature working through many centuries developed the original forest and gave it to us grat- uitously. Man working through only a few centuries has established a great industry — the lumber industry; but on the other hand he has wastefully exploited our forests and left many of them in an un- productive condition. However, there was no alternative because the eco'nomic conditions then prevailing required, in part at least, this wasteful procedure. FORESTS OF PENNSYLVANIA. The word Pennsylvania means Penn's woods. It derived its name from its early proprietor and the dense and extensive forest growth (13) 14 , which covered the State. The original forest covered almost its en- tire area, which is usually given as 28,594,560 acres. Practically the entire State, with the exception of a few natural meadows and the tops of a few mountains, was covered with trees. The original forest was composed of many and valuable species often occurring in dense sttmds. th,:e richness of our forest flora is due to its favorable location with reference to climatic and physiographic factors. Penn- sybniiia ii&Wjnoftt&g ground of many northern and southern spec- ies. In the western part of the State one finds outposts of species common to the Mississippi valley, while in the southeastern part some of the species of the coast region are found. Some of the north- ern species have their southern limits here, or else follow the moun- tains toward the south, while some of the southern species have their northern limits here, usually migrating northward through the val- leys. The forests in the southeastern and the western parts of the State are composed almost entirely of hardwoods, while the central and the northern or mountainous parts are composed of a mixture of hardwoods and conifers. One may find the hardwoods by them- selves and the conifers by themselves, or they may occur in mixture. A few of our native species are very valuable, while others are less valuable and some mere forest weeds. The real value of a species changes with the change of the general economic, particularly market, conditions. Within the last decade market prices of wood have risen so much that they have brought about a more intensive utilization of our forest products. Many species formerly left standing in the forest are now utilized. A moment's reflection upon the present tendency in the utilization of the products of the various trees causes us to comprehend fully the truth of the statement that the despised species of to-day will be prized tomorrow. The richness of the arborescent flora together with the great age and large size which some of the trees attained justifies the statement that Pennsylvania was at one time "one of the best timbered states of the Atlantic Coast." Nature working through many centuries developed in this State a forest which was one of the most valuable of the many heritages with which its citizens have been blessed. If we could see maps showing the structure and distribution of the forests of Pennsylvania in the years 1600 and 1900, we would be astonished by the wonderful change that has taken place in a period that represents only a few generations of trees. Many were the agents which brought about this change, but it was left to man to play the leading role. Man working through a few centuries has removed the forest or abused it through fire and unregulated cutting. The establishment of pio- neer homes, the opening of agricultural and grazing lands, the in- crease of population, the development of industrial enterprises, the Fig. 1. STAND OF PENNSYLVANIA VIRGIN WHITE PINE. The kind of forest our forefathers found. A magnificent heritage. The real value was not appreciated. "' -• ' • Fig. 2. RESULT OF EXTENSIVE FOREST EXPLOITATION. High stumps, and a thin scattered growth of inferior trees, is all that remains. The stumps indicate the density and size of the original stand. Fig. 3. ACRES OF DESOLATION. More than 5,000.000 acres of such barren land are found in Pennsylvania. Much valuable timber was lost through reckless exploitation of the original forest. ACRES OF SCRUB OAK 15 destructive work of lumbermen, and the advent of forestry present a picture of change and progress, which enables us in part to com- prehend the important role that man played in transforming the original forest into the present forest. Pennsylvania originally contained large, dense, and extremely pro- ductive forests. The large have become small, the dense have be- come open, the productive have become unproductive. Each genera- tion of mankind has seen a smaller, more open, and less productive generation of forests. The march of forest destruction has been rapid and severe and yet inevitable on account of existing economic conditions. While originally almost the total area of the State was covered with tree-growth, to-day less than 50 per cent, is covered by woody growth and over 5,000,000 acres of this is barren or un- productive, while many more acres are poorly stocked with trees. Most of our woodland areas are 'at present in a very unproductive unsanitary, unattractive, and unregulated condition. Economic conditions have changed and the old order of things need not continue. We must substitute conservative lumbering for the wasteful exploitation of the past. We must do constructive work in our forests now to recompense for the destructive work carried on during the last few centuries. We should aim to show our social and civic worth by handing down to future generations a heritage equivalent to that which we received from our forefathers. In order to do proper constructive work it is necessary to establish a goal or an ideal and develop proper methods by which it can be reached or at least approximated. We need not be entirely original in this work since a few countries like Germany, Switzerland, and France have already in more than a century of experience laid the founda- tion for conservative and constructive forestry. We can learn much from these countries. A visit to their carefully managed forests together with a general survey of the methods which they use in managing them will be helpful in formulating plans for our Ideal or Normal Forest. We may not be able to adopt their methods but we can at least adapt them. The question at once presents itself: How can we improve our woodlands so that they will approach the well-managed forests of Germany, or the ideal or normal goal which we are setting up for them? The following answers suggest them- selves : 1. By giving adequate protection. Fire is the chief agency against which our forests need protection. 2. By procuring wise taxation. 3. By prohibiting unregulated cutting. 4. By securing quick reproduction after the removal of the timber. 16 5. By establishing a complete stock of valuable trees on all forest soils. 6. By removing undesirable stock and replacing it with a better class of trees. 7. By establishing a proper proportion and a suitable distribu- tion of age classes. 8. By making every part of the forest accessible by means of roads, lanes, trails, paths, compartment lines, etc. 9. By making improvement cuttings. 10. By dividing the forest into working units (compartments) just as a farmer divides his farm into fields and the fields into patches. THE FORESTS AND FORESTRY. The original forest was so modified by the activity of man, or man working conjointly with natural agencies, that the source of our future wood supply became a question of great importance. A gen- eral survey of the field showed that we were consuming wood faster than we were producing it. This unbalanced economic condition due to the unregulated condition of our forest gave birth to the sub- ject of forestry. Man's attitude towards the forest showed that he was a disturbing agent. Without him the forest of Pennsylvania would have remained practically undisturbed, indefinitely. Hence it might follow that the forest thrives best where there are no people, and consequently no forestry. Further, one often hears the state- ment: Formerly we had no forestry and plenty of wood; now we have forestry but no wood. This statement does not prove that for- estry is to be blamed for a deficiency in our wood supply, but it does prove that forestry is the child of necessity. This child of nec- essity, which is at present just in its formative period, could never have been born if we had not been compelled to see that our timber resources were rapidly decreasing. The word forestry to many may be new. The most enlightened may have a rather vague conception of its exact scope. It is often identified with the planting of individual trees, landscape work, and tree surgery. Forestry should be regarded as the rational treatment of our woodlands for their products. The kind of treatment de- pends largely upon the desire of the owner. The ownership may be private or there may be a public owner, as a municipality, a state, or a nation. The desire of the owner may be to supply wood ma- terial, to retain or establish a protective cover, to furnish recreation grounds, or to maintain a game cover. The forests which are man- aged for the purpose of producing a supply of woody material are known as production forests or supply forests, while those which Fig. 5. DENSE STAND OF NORWAY SPRUCE, GERMANY. The kind of forests we hope to develop. Norway Spruce is a valuable and a beautiful tree. Fig. 6. CAREFULLY MANAGED FOREST. Attractive, sanitary, productive, and organized. Good roads ramify through all its parts. Fig. 7. FOREST ACADEMY STUDENTS IDENTIFYING TREES IN WINTER. Fig. 8. FOREST ACADEMY STUDENTS STUDYING THE GROWTH OF TREES IN A PLANTATION. Fig. 9. FOREST ACADEMY STUDENTS ESTIMATING TIMBER. 17 are retained or often established as a protective cover are known as protection forests. Protection forests aim to prevent calamities like destructive floods, excessive erosion, sand shifts, and snow shifts. Forests managed primarily to enhance the beauty of the forests and to furnish recreation grounds for the public may be known as park forests. Park forests should always be accessible to the public. Such outing grounds will not only be a means of preventing many of our diseases but also help to restore to health those who are already afflicted. Forests managed by the owner primarily to en- joy sport are known as luxury forests. Forestry aims to have man improve upon nature's ways of doing things. Nature grew forests upon areas regardless of the fitness of these areas to other more profitable pursuits. Both the thin, rel- atively sterile soils of the mountains and the deep, fertile soils of the valleys were covered with forests. The latter are far more valuable for the production of food material than for the production of wood material. Forestry aims to develop forests on forest soil. It does not attempt to encroach on agricultural soil but aims first to classify the land into ploughland and woodland; and then to treat the woodland areas so that they will yield the largest quantity of high class wood material in the shortest time at the least expense of time and money and to give to mankind as many other natural blessings as possible. The economic point of view should always be kept paramount. The forester's forest should supply more fully the pres- ent and prospective human wants than they can be supplied by de- pending upon nature's uncertain and unregulated performances. FORESTRY IN PENNSYLVANIA. Forestry had an early beginning in Pennsylvania. As early as 1681 William Penn in his Charter of Eights stated that "In clearing the ground care should be taken to leave one acre of trees for every five acres cleared; especially to preserve the oak and mulberries for silk and shipping." From this time on at irregular intervals acts were passed by the legislature protecting the woodlands from theft and firing; but no real, constructive work in forestry was done until the latter part of the 19th century. In 1855 F. Andre Michaux left a legacy of $14,000 to the American Philosophical Society in Philadelphia which became available in 1870 for forestry instruction. In 1877 Dr. J. T. Rothrock, Professor of Botany at the University of Pennsylvania, was appointed Michaux lecturer on Forestry, in which capacity he served until 1891. At this time it was difficult to interest the public in forestry and, as a consequence, at first, the lectures delivered by Dr. Rothrock were 18 not well attended. The interest in forestry, however, grew gradually and cumulatively. In June, 1886, the Pennsylvania Forestry Association was founded. It has always been and is still one of the best and most constructive organizations of its kind in America. In 1888 Governor Beaver appointed a Commission on Forestry, which was the first commission of its kind in this State. It presented a report to the legislature in 1889. The reports which this and the subsequent commission pre- sented to the legislature, together with the data obtained from the tenth census (1880), helped to stimulate interest in forestry on the part of both legislators and the public. In 1895 the Division of Forestry was create^ in the Department of Agriculture and Dr. J. T. Rothrock was appointed Commissioner of Forestry. He served in this capacity until June 1, 1904, when he resigned. Hon. Robert S. Conklin, the present incumbent, succeeded him as Commissioner of Forestry. Under the direction of these able men the forestry work has progressed to such an extent in less than two decades, that Pennsylvania to-day stands in the front rank with reference to the development of its woodland areas. Many constructive acts pertain- ing to forestry have been passed by the legislature, some of which have served as models for other states. In 1901 the Division of Forestry was raised to a Department of Forestry. In 1903, by a special act of the legislature, the State Forest Acad- emy, at Mont Alto, was established. Mont Alto is a small village in Franklin county, sixty miles southwest of Harrisburg on the Cumber- land Valley Railroad. The ground occupied by the school buildings is a part of a State forest which affords an excellent opportunity for practical instruction and an accessible field for experimentation equalled by few if any forestry schools. Recently one of the leading forestry educators connected with an American University, a Ger- man by birth, in a public address said, "The Pennsylvania State Forest Academy has the best location and working field of any forestry school in the world." This school aims to train young men in prac- tical forestry so that they will be able to manage the State forests. Sixty-four men have been graduated, and most of whom are still in the service of the State. In addition to these foresters ninety-two rangers are also employed. A printed announcement of the school is available for free distribution and will be sent upon request. The State authorized the purchase of woodland areas in 1897 for the purpose of establishing State forests. To date (July 1, 1915) 1,003,114 acres have been acquired, located in 26 counties, at a total cost of $2,284,587.90, or an average of $2.27 per acre. This area is now being developed. Over 5,000 miles of roads, lanes and trails have been built, opened, or repaired. One hundred ninety-five miles of telephone lines have been built and numerous fire observation 19 towers have been constructed. The Department of Forestry aims to disseminate knowledge concerning forestry to the public, to protect carefully all State forests, to assist in the protection of private areas, and make accessible for management and utilization all State forests as rapidly as appropriations by the legislature will permit. Many large areas in various parts of the State are devoid of any valuable tree growth. Most of these areas are capable of developing useful forests. In order to have them developed it is necessary that such areas be stocked with valuable trees. It must be done by planting. About 6,000 acres have already been planted to trees in this State, which required a total of 11,970,500 seedlings. In order to produce these seedlings and to insure a future supply 4 large forest nurseries and 22 small ones have been established. Many other benefits are de- rived from the forests. They serve as recreation grounds to the public who seek their midst to regain or maintain health. Carefully managed forests regulate stream flow and are also the sources from which cities and towns obtain an excellent supply of unpolluted water. They furnish local labor, and, through permits, suitable camp sites to campers, hunters, and fishermen. The sale of material from the State forests has already yielded over $96,600 which will be set aside for "The State School Fund of Pennsylvania." THE STRUCTURE OF THE FOREST. Every region and, often, even every small locality has its peculiar kind of forest. The composition of the forests along streams, on slopes, and upon mountain tops usually shows great differences. The climatic factors and physiographic features of a region influence the composition of the forest very much. The more varied the factors of the habitat are, the more varied the composition of the forest usu- ally is. Upon the same mountain slope one can often find three and sometimes more zones of trees. Each zone is composed of different species or groups of species, which groups vary not only in composi- tion, but also in form, density, and thriftiness. The forester seldom considers trees raised in isolated positions, but rather concerns himself with trees raised in masses or stands. Such masses of trees, irrespective of their kind, size, density, form, number, or value are known as woodlands. Woodlands may be com- posed of a single species or of two or more species. If one species composes ninety per cent, or more of the total stand it is known as a pure stand and if the stand is composed of two or more species none of which forms ninety per cent, of the total stand it is known as a mixed stand. Woodlands are rarely quite pure. A slight ad- mixture of some species is usually present. The forests of Pennsyl- 20 vania are decidedly mixed in their composition. The conifers are found oftener in pure stands than the broad-leaved species. Since the forests of this State are composed largely of hardwood species it is rather unusual to find pure stands. Occasionally one may find small pure stands of such species as Pitch Pine, White Pine, or Bed Cedar and rather extensive ones of Chestnut. About 125 species of trees are native to the State of Pennsylvania but not more than 25 species are of sufficient importance to deserve to be developed in our future forests. A large proportion of our native trees is found as undergrowth. They form dense and some- times almost impenetrable thickets. This dense and complex struc- ture of our underwood aids considerably in increasing the number of participants in our forests. Dense and tall undergrowth tends to protect the soil from erosion, to conserve the fertility of the soil, and to afford shelter to birds which prey upon the insect enemies of the forest; but it may also impede the utilization of forest pro- ducts and make the tending of the forest more difficult. The tendency of forestry is to eliminate the undesirable species. We should eliminate cautiously since the despised species of to-day may be' prized to-morrow. If this process of elimination is devel- oped on an intensive scale, it means a reduction in the number of species and, in extreme cases, leaves only one species, i. e. a pure stand. This is especially true where a forester aims to establish a stand by artificial seeding or planting. He is apt to choose a species, which he thinks will give the highest returns. If he selects the proper species and it is not injured during its development he may possibly obtain satisfactory results. Before establishing stands one should consider the subjoined advantages of pure and mixed stands. The principal advantages of pure stands are: — 1. Pure stands are easier and cheaper to establish. 2. Pure stands are easier to tend and manage. The principal advantages of mixed stands are: — 1. Mixed stands utilize the available plant food in the soil and air more fully. Close utilization of the factors of the habitat and keen competition by every forest tree upon its neighbor are requisites for optimum quantity and quality production. 2. The forester can meet the demands of the market better with a few species than with one species. 3. A larger number of trees per unit of area is usually found in a mixed stand than in a pure stand. 4. Many species are less subject to damage by wind, frost, fire, fungi, and insects, in mixture than when grown pure. 5. Trees usually develop a better form if mixed properly than if grown pure. 6. Mixed stands are more attractive than pure stands. 21 A great many pure stands may be seen in the forests of Germany. Some of them were established over 100 years ago and are now ready to be cut. After more than a century of experience in planting, the German foresters are abandoning the policy of establishing pure stands and are advocating mixed forests. Mixed forests may con- sist of a mixture by single trees or of a mixture by groups. The mix- ture may be temporary or permanent, even-aged or uneven-aged. We should aim to improve the composition of our forests by re- ducing the percentage of inferior species and increasing that of the more valuable ones. The present cover types which consist of many despised, some neutral, and a few prized species, should be transformed into the future management types which will be charac- terized by a simpler but superior composition. THE ESTABLISHMENT OF THE FOREST. As rapidly as the mature forests on absolute forest soil are re- moved they sould be succeeded by young forests. These new forests which follow in the wake of those removed may be established by one or by a combination of the following methods: — (1) Natural, where nature, aided to a limited extent by man, sows seeds and produces sprouts. (2) Artificial, where man sows the seeds or plants the seedlings. The former is usually spoken of as natural regeneration and the latter as artificial regeneration. In both methods nature does most of the work; but man helps nature more in the artificial method than in the natural method. Nature working through many centuries produced the original forest. We cannot wait for nature to produce another original forest on our forest soils. It will take too long. We may assist nature and attempt even to improve upon its way of doing things; but we must be careful that we do not de- viate too far from its methods for fear of being punished. In the case of artificial regeneration it is necessary to collect seeds from desirable trees. These collected seeds may be sown imme- diately or stored. If stored, they must be protected from such ani- mals as mice, squirrels, and birds, and from drought. The seeds may be placed between layers of sand to prevent drying out. Those seeds which are sown immediately may be sown directly upon the area where they are expected to germinate and establish themselves or they may be sown in beds in a nursery where they in time develop into seedlings. Direct sowing may be in the form of broadcasting, where the seeds are scattered rather uniformly over the area or spot planting, and where only isolated or scattered spots, often regularly spaced, are sown with seeds. The nurseries in which the seeds are sown may be permanent and located in the open, or temporary and located in the forest under the 22 shelter of trees. The nursery is divided into a great number of beds which are usually about twenty-five feet long and four feet wide. The seeds may be sown in these beds in spring or fall, either by sowing them broadcast or in rills. Here the seeds germinate and after an incubation period of usually less than a month, but occa- sionally extending over a year, they appear above the ground. The germination can sometimes be stimulated by soaking the seeds in water before planting. These young tender plants like children suc- cumb very readily to adverse conditions. Consequently they must receive careful treatment and adequate protection while they remain in the nursery. They must receive protection from the intense sun, excessive moisture, drought, weeds, fungi, and animals. The plants which develop from the sown seed may remain for one, two, or three years in the nursery. Those plants which remain for more than one year may be kept in the same place where the seeds which produced them were sown. If too dense they must be lifted and planted in another place where they will have more room. This process of lift- ing the seedlings and planting them again is known as transplanting, and the resulting plants are transplants. Transplanting usually produces better plants because they are stockier and better prepared for the shock they will receive when planted in the forest. Species like. White Pine, Red Pine, and Norway Spruce are usually left in the nursery for two or three years and then transplanted while other species like Ash, Walnut, and Oak are left in the nursery only one year. The seedlings planted in the forest are usually raised in nurseries but occasionally they may be taken from the forest floor where na- ture often produces them abundantly. The cost of raising plants in the nurseries varies with the species, cost and quality of the seeds, and the length of time left in the nursery, but is usually from about |2.50 to $4.00 per thousand. The source, method of collection, pre- paration, and" storage of the seeds have a marked influence on the quality of the resulting plants. The plants, taken from the nursery or lifted in the forest, are usually planted in the forest about 4x4 or 5x5 feet apart. This requires from about 1,700 to 2,725 trees per acre. The total cost of planting an acre of cleared land to forest trees, including cost of plants, is about $12. In individual cases the cost may exceed this figure and again it may be lower. This ar- tificial method of regeneration is generally used where forests have been clear-cut or where openings are to be reforested. It is also used for underplanting where a better humus covering is desirable. In Europe, especially in Germany, this method was used extensively (luring the last century as may be seen in the many even-aged forests found there at the present time. During the last decade a reaction has been setting in, based on scientific investigations. Many of the Fig. 13. DEVELOPMENT OF WHITE PINE SEEDS. Seedlings taken from nursery May, 1914, after growth had started. From left to right: Four seeds; six seedlings from fall-sown seeds showing 3 stages of development directly after breaking through the ground; two 1-year old seed- lings ; two 2-year old seedlings . Fig 14. STUDENTS PLANTING TREES. From 1,200 to 2,750 trees are planted per acre. A crew of 20 men can plant 20,000 trees per day if conditions are favorable. Fig. 15. NATURAL REGENERATION OF THE FOREST. Norway Spruce before seeding cutting. Opening the leaf-canopy stimulates seed production . Fig. 16. NATURAL REGENERATION OF THE FOREST Norway Spruce after seeding cutting. Regeneration following regulated seed pro- duction. Fig. 17. NATURAL REGENERATION OF THE FOREST. Large Oak seed tree with its offspring. Fig. 18. NATURAL REGENERATION OF THE FOREST. An opening being filled by a dense growth of White Pine, Tulip, and Hemlock seed- lings, from seed scattered by bordering large trees. Fig. 19. PLANTATION OF WHITE PINP]. Six years old from seed, about 2,000 trees, 2-3 feet high, per acre. Fis. 20. PLANTATION OF WHITE PINE .leven years old from seed, about 2,500 trees, 5-12 feet high, per acre. 23 forests which were established artificially are now reaching maturity. Disadvantages of this method are becoming more evident and the foresters are gradually substituting the natural method for the ar- tificial. The natural regeneration of forests may take place in two ways: (1) By coppice and (2) by seed. By coppice is meant the shoots which spring up from the stump when the tree is cut (Figs. 23, 24, 69, 79) and the suckers which spring up from the roots. Coppicing is a rather important method of reproduction in Pennsylvania since some of our most valuable species, like Chestnut, Ash, and Oak re- produce readily by this method. Natural seed regeneration leaves most of the work to nature. Man attempts to hasten it somewhat by regulated cutting in the stand and by wounding the soil so that the seeds will find a favorable mineral soil upon which to germinate. The trees which produce the seeds may be scattered singly, or occur in groups, in strips, or in opened stands. These trees are known as seed trees or mother trees. Some form of natural regeneration must be used in protection forests, is advisable for game and park forests, and applicable to the forests which are managed for the production of wood. In some cases it is advisable to begin with natural regeneration and then fill in artificially all places which are not stocked with trees. THE DEVELOPMENT OP THE FOREST. The raising of some farm crops and the raising of a wood crop have many points in common. A farmer after planting his field to corn in spring does not leave it to nature to develop and mature, but he cultivates it and sometimes even cuts out undesirable sprouts called suckers, knowing that careful tending will result in a larger yield. Likewise the forester is not satisfied in establishing a forest but he also aims to develop or tend it so that it will yield a large and val- uable crop. The method of developing a forest depends upon the nature of the forest and the desire of the owner. The forest may have been es- tablished by nature and even partly developed by it or it may have been established by man. The forests established and developed by nature without the aid of man are usually in a rather unsanitary, unattractive, unproductive, and unregulated condition. Under such conditions it is necessary for man to transform these into forests which are clean, attractive, productive, and which show evidence of proper regulation on every hand. The forests which man establishes usually start out with 2,000 to 20,000 or even 50,000 seedlings to the acre, depending upon the method of establishment. If artificial methods of regeneration are used about 2,500 seedlings per acre are 24 required but where natural regeneration is used one may find 20,000 or even 100,000 seedlings per acre. If we go into a mature forest stand and count the trees per acre we will find probably 150, or some- times 250, and occasionally 400 ; hence, we must conclude that a large proportion of the trees which start out cannot survive. Two ques- tions suggest themselves: What happens with the large number of trees which cannot mature? Why is it necessary to plant so many when only a small number can mature ? If one inspects a plantation of trees a few years after it was established he will be able to note a difference among the trees. Some are thrifty, which is shown by their rapid growth, others are average, while still others show no signs of growth whatever or may have died. If one returns ten years later this condition is still more pronounced. By this time they will have grown to such dimensions that their branches are beginning to interlace. A struggle has started between them. There is no longer sufficient space for all of them. They must battle with each other for light and food. Some will conquer and be known as domin- ant trees, while others will just about hold their own and be known as intermediate trees, while still others will be conquered and be known as suppressed or dead trees. This struggle for existence is found in all places where trees grow in the form of a forest, and re- sults in the elimination of the weaker specimens. At the same time it gives such drastic discipline to the dominant ones that they will produce a much higher grade of wood. Trees grown in dense stands are usually free from lateral branches for a consider- able distance from the ground and as a consequence the logs cut from them will be relatively free from knots; while trees grown in open stands or in open situations bear crowns which often reach almost to the ground and produce numerous knots. Such trees as the latter, consequently, yield an inferior grade of wood. In developing forests the owner or forester in charge should aim to maintain a proper number of trees per acre and to treat them so that they will not only yield a large quantity but also a good quality of wood. He should not aim to differ from nature's ways of doing things but improve on them. In order to improve the for- est it is necessary that the forester carry on certain operations in the immature stand which aim to improve the composition of the stand and the form of the individual trees. He should also aim to increase the rate of growth of the individual trees and as a result increase the yield in volume and value of the final product. The principal operations which one must carry out in order to realize the above objects are: Cleanings, Liberation Cuttings, Thinnings, Damage Cuttings, Pruning, Weeding, and Underplanting. Cleanings are cutting operations in young rather even-aged stands which remove undesirable trees with little prospective value, and Fig 23. THINNED CHESTNUT STAND. About 35 years old. Approximately 280 trees over 4 inches in diameter, breast high, still standing. Eight cords of wood per acre were removed. AK 22 years 24. THINNED CHESTNUT STAND Fig. 25. WHITE PINE STAND BEFORE AND DURING PRUNING. Fig. 26. SAME STAND AS FIG. 25, 10 YEARS AFTER PRUNING Fig 27 OIL PIPE LINE AS A FIRE AND SUBDIVISION LINE. A base from which to fight fires. An excellent subdivision line. Fig. 28. COMPARTMENT LINE IN A YOUNG CHESTNUT FOREST. . Such lines afford a base for controlling fires, and make the forest accessible. 25 favor other species with a good prospective value. These latter may have been overtopped by the undesirable ones. Liberation Cuttings are operations in immature stands in which the main crop of trees is overtopped by scattered older trees with very wide-spreading crowns. These older trees with present but little prospective value retard the development of a great number of younger trees with good prospective value. The removal of the larger trees is known as a Liberation Cutting. Thinnings are cutting operations in immature stands for the pur- pose of accelerating the growth of individual trees and, as a con- sequence, increasing the total yield and improving the quality of the product. Thinnings result not only in a larger quantity and quality increment but aim to improve the appearance and health of the forest. They decrease the danger from fire since a large amount of inflam- mable debris is removed. If thinnings are conducted properly the remaining trees are usually more windfirm. Thinnings also enable one to get returns upon a forest investment without waiting until the crop is finally harvested. Today, under our crude method of regu- lating the returns from our forests, the thinnings or intermediate yield play a minor role, while the final yield comprises practically the total yield ; but as our methods are developed and perfected, the intermediate yields will comprise as in the intensively managed for- ests of Germany, 25%, and later, 50% of the total yield. All forest owners should aim to improve their forest stands by thinning them properly so that they will become more attractive, more sanitary, and more productive. This may be accomplished by thinning early, regularly, and with increasing intensity, but always cautiously, so that the fertility of the soil will be conserved and all available food properly utilized. Damage Cuttings comprise operations which remove all damaged material from the forest. The damage may be caused by wind, light- ning, snow, insects, fungi, fire, or any of the many other agents which operate in the forest. Damage cuttings should be made as soon as possible after the damage is done not only in order to utilize the ma- terial before it depreciates too much in value, but also to prevent the spread of such destructive agents as insects and fungi. Pruning is an expensive operation and consists mainly in cutting off the lower branches of trees where they were not pruned natur- ally, in order to produce stems with as few knots as possible and at the same time increase the beauty of the stand. Underplanting is an intensive cultural operation which is practiced only under systems of intensive management of the forest. It may aim to conserve or even improve the soil or to establish advance reproduction. The aesthetic value of underplanting is also a valu- able asset in developing our forest. 26 Environmental influences and inherent tendencies are factors which are constantly discussed in connection with the development of our youth into useful men and women. These same factors should be considered in developing the young seedlings of the present forest into the veterans of the future. THE PROTECTION OF THE FOREST. The protection of the forest surpasses in importance all other for- est activities during the early or formative period of forestry in any country. Forest protection is not only the oldest but also the most necessary branch of forestry. Many and varied are the destructive agents at work in the forest or upon the products derived from it. The destructive work of fire is very evident while that of fungi is often hidden. One cannot help but comprehend tho destructive work of a forest fire which may sweep over an entire mountain, kill every trace of tree growth, and, in addition, destroy buildings and oc- casionally human lives; but few even apprehend the extent of damage by such agents as fungi which often cause the decay of the entire interior of a tree without giving any external evidence of their pres- ence. In order to give adequate protection to our forests, it is nec- essary to know the dangers which threaten them. We must also know how to offset attack by employing preventive and remedial measures. The principal dangers which threaten the forest and against which man must protect it may be grouped as follows: — 1. Damage from human agencies. 2. Damage from organic agencies. 3. Damage from inorganic agencies. Man's disturbing influence in the forest can be comprehended in part when one compares our present forests with those of the past. Primitive man had few wants, but as his civilization progressed his wants multiplied and his destructive tendencies became more ap- parent. The early settler found it necessary to destroy valuable forests for the purpose of establishing a home and for opening agri- cultural and grazing lands. He had no alternative then, but now conditions have changed. He is just at the beginning of forest ap- preciation. He must introduce system and substitute conservative forestry for destructive lumbering, which latter has always been characterized by profligate exploitation and wanton waste. Man is directly or indirectly responsible for most forest fires, since they usually originate through his carelessness or malicious- ness. Lightning is responsible for a very small percentage. Of all the enemies of the forest none is so destructive as fire. A single fire may burn over a few acres only or it may burn over thousands of acres in a single day. It not only destroys present but prospective value, since it consumes or kills mature trees and the young seed- Fig. 29. HEMLOCK TRUNK WITH FRUITING BODIES OF A FUN- GUS. Fig. 30. BLACK BIRCH TRUNK AT- TACKED BY TWO DIFFERENT SPECIES OF FUNGI. Fig. 31. CHESTNUT POST ATTACKED BY BROWN ROT (POLYPORUS SULPHUREUS). Some fungi attack only living wood, ethers attack only dead wood. Fig. 32. WHITE OAK AND PINE LOGS ATTACKED BY FUNGI and fungous attack f Fig. 33. PRESIDENT JAMES BUCHANAN'S BIRTHPLACE. Buchanan State Forest, Stony Batter, near Mercersburg, Franklin County, midal rough stone monument. Norway Spruce in the foreground. Pyra- 27 lings and saplings which would have produced the forest of the fu- ture. In the years 1907, 1908 and 1909, 2,455 fires occurred in the State of Pennsylvania, and burned over 484,987 acres. The esti- mated amount of damage was almost $1,000,000. It is also esti- mated that the average annual direct loss from forest fires within Pennsylvania is $500,000. Three kinds of forest fires are usually recognized: Surface fires, which burn the surface layer of leaves, grass, twigs, and some trees; Ground fires, which burn through soils with abundant vegetable ma- terial; and Crown fires, which burn through the crowns of trees. Many fires can be prevented by educating the people concerning the real value and significance of the forests. Vigilant patrol dur- ing the danger season, the construction of fire- towers, telephone lines, roads, fire-lanes, compartment lines, and the proper disposal of com- bustible material, help to minimize the fire danger. The damage which man does in the forest is very noticeable to his fellowman, while that done by other agents often goes unnoticed. Due to the development of our biological sciences in the recent past we are beginning to appreciate the extent of the damage done by such agents as insects and fungi. The organic agencies which damage the forest are plants or ani- mals. The principal types of plants which do damage to the forest or to the products of the forest are parasitic flowering plants, as the mistletoe, and fungi which cause the decay of wood. The extent of damage which fungi do to trees as well as construction timber is usually underrated. They may be found upon living or dead trees, stumps, logs, railroad ties, and construction timber in bridges, houses and barns (Figs. 29-32). The Chestnut Bark Disease is an example of a parasitic fungous disease which attacks the Chestnut tree, doing enormous damage. Many different kinds of animals do damage to the forest. Domes- tic animals, as cattle, sheep, goats, and hogs, and wild vertebrates, as deer, rabbits, squirrels, mice, and beavers, are among the most im- portant damaging agents. Next to fire, insects are the most destructive enemies of the forest. They may infest young seedlings in the nursery, the fruit or seeds, the twigs, the cambial bark, and the wood. They also do consider- able damage by attacking the leaves. Complete defoliation is not uncommon. The damage from inorganic agents may be in the form of wind- fall, wind-break, snow-break, excessive cold, excessive heat, shifting- sands, erosion, floods, and noxious gases. Proper protective measures can sometimes be carried out success- fully by the individual, but in other cases the co-operation of the nation, state, or municipality may be required. Organizations or 28 establishments for carrying out protective measures are also re- quired where large areas are to be protected. On July 1, 1914, there were employed in Pennsylvania 56 Foresters and 91 Forest Kangers to look after the 998,773 acres of forest land which the State owns. Most of the foresters employed fey the State received their training at the State Forest Academy. By developing the forest fire organiza- tion in Pennsylvania, forest fires will be rare events, as in the man- aged forests of Europe, and if they do break out will cause relatively little damage. THE VALUE OF FORESTS. Prior to the time that the conquest of Constantinople closed the route to the Orient, the Atlantic was regarded the world's back door. Columbus, a mere sea captain, to his own surprise, discovered a land which, as the old voyagers related, no one approached without appreciating the beauty of the forest. Those old voyagers appreciated the beauty of the forests but not their prospective value. The forests at first had a negative value. They were something which must be conquered. Their removal was necessary for the establishment of homes and the opening of agricultural lands. Thousands of acres of the best forests were simply burned to get rid of them. They were obstacles in the way of development. Gradually as our forest acreage decreased, as our population in- creased, and as the demand for wood goods multiplied, the forests be- came not only objects of interest and beauty, but also of value. After four centuries of rapid development we are just beginning to comprehend the real importance of our forests. They supply us with wood which is the most indispensable and universally used product of nature. Wood as a necessity or a luxury is used in our various activities from the cradle to the coffin. Many of our houses are built, finished, and heated with wood. Most of the paper upon which we write and upon which our books are printed is made of wood. The forests supply us not only with wood but with many minor products like maple sugar, tanning materials, naval stores, charcoal, wood alcohol, etc. Artificial silk and even whole suits of clothing have been made from wood. In addition, the forests furnish leaves for stable litter, pasturage for cattle, pannage for swine, and great quantities of nuts which are used as food by man. Pasturage was formerly carried on more extensively than at present. It may be a legitimate industry if it pays and if it is so directed that the "young seedlings in the forest, which will produce our future forests, are not eaten or injured. As a rule, grazing should not be permitted in 29 young forests where the shoots are still tender and readily eaten by animals, nor where the grazing animals may tramp out the seed- lings. The original forest may be regarded a great reservoir of wealth filled by nature working through many centuries, and exploited by man either for its products or to establish in its place a more neces- sary industry. The present forest on the other hand may be rep- resented by a much smaller reservoir only partly filled, and with material which is inferior not only to that found in the original forest but also far inferior to that which we hope to develop in the future forest. The present forest if properly managed, which im- plies improvement, is capable of producing continuously a large quantity of major and minor forest products representing an enor- mous value. In addition to the usual monetary value of forests we should also consider their value as soil formers, soil fixers, soil im- provers, preventers of floods, sanitary agents, suppliers of natural blessings, and beautifiers of the earth. THE VALUE OP TREES. Trees are among the commonest and most conspicuous objects of nature. They vary considerably depending upon their kind, their environment, and the artificial treatment which they may have re- ceived during their development. The trees which surrounded the simple home of the early pioneer differed very much from those which adorn the grounds of some of our wealthy citizens today, showing that nature, unaided by man produces trees in the forests which differ considerably from those which man has planted and cared for. Environment is a very potent factor which not only in* fluences the general appearance of a tree but also the structural parts which compose it. Trees as members of the forest stand have been considered in the preceding chapter. The subjoined material treats of trees used for purposes other than forestry. Trees are not only valuable for their products, as wood, resin, fruit, and litter, but in addition have an aesthetic and a protective value. Although tree-planting for shade and ornament has been practiced assiduously in past generations, yet the value of such plant- ing and the care which such trees require and should receive has not been fully appreciated until lately. Today individual trees or small groups of them are planted rather extensively about homes, along streets, in parks and public squares, for their shade and shelter. They are also used about the home to screen objectionable objects, to direct and restrict the views along general lines, to frame the home picture and to give the surroundings the expression of comfort and homeliness. 30 The establishment and care of shade and ornamental trees is en- tirely different from the care of forest trees. Knowledge concern- ing the life-history of trees in general is, however, a prerequisite for the proper treatment of both classes of trees, but the art by which this knowledge is applied is entirely different. The forester grows trees to harvest and at harvest time he aims to obtain from them as much and as high grade wood as possible. The tree warden grows trees to preserve. He aims to develop a tree with as desirable an appearance as possible and to retain it as long as the vitality of the tree will permit. Thousands of dollars are spent annually by shade and park com- missions in developing the aesthetic side of our cities, towns, and many of our rural districts. The commissions or individuals who have this in charge, aim, by beautifying the environments, not only to improve the health and efficiency of the citizens, but also to raise their moral standard and hence increase their social worth. DECIDUOUS AND EVERGREEN TREES. All trees native to the State of Pennsylvania, when in a healthy condition, bear green foliage in summer. In autumn many of the green leaves change to brilliant colors, yellow, scarlet, deep red, or purple, and gradually fall to the ground. The species of trees whose leaves lose their green color and fall in autumn are known as deciduous trees. Most of the trees native to the State of Pennsyl- vania are deciduous. The deciduous trees are also known as hard- woods or broad-leaf trees. The Oaks, Maples, Birches, and Chest- nut are common examples of this group. Many of the representa- tives in this group yield valuable products and furnish interesting objects of study on account of their variation in form. In winter the deciduous trees are far more conspicuous than in summer since the dense leaf canopy is absent. This affords an opportunity to study the trees with special reference to their form, branching, and bark. These characters are among the most helpful in distinguish- ing our common trees, especially since they are at hand at all sea- sons of the year. The leaves of a few deciduous species like the Beech and some of the Oaks die in autumn but often persist through the winter. Some species, however, do not shed all of their leaves in fall. Such trees are known as evergreen trees. The evergreen habit is char- acteristic for most trees commonly known as conifers. Most of the conifers have needle-shaped leaves which persist for two or more years. The Larch, native to this State, and the introduced Bald Cy- press are, however, two species which shed all their leaves in fall and during the winter appear like dead conifers. The persistence of the 31 foliage of most of the conifers enriches the winter scenery and af- fords shelter for birds and other animals. Many conifers are highly prized for ornamental purposes and some yield valuable commer- cial products. The Pines, Spruces, Firs, Cedars, and Hemlocks are the commonest examples of this group. Tn addition to the conifers a few broad-leaf species, such as Rhododendron, Mountain Laurel, and American Holly, are evergreen. A transition from the evergreen to the deciduous habit may be found in the Deciduous Holly and the Laurel Magnolia which are deciduous in the northern and evergreen in the southern states. The deciduous trees are commonest in the eastern part of North America while the evergreen are commonest in the western part. The former are usually found in mixed stands, while the latter often occur in extensive pure stands. The hardwood species usually occur on rather fertile soils while the conifers may thrive on more sterile ones. Both the deciduous and the evergreen habits have their ad- vantages. The shedding of the leaves in fall is a protective adapta- tion since it reduces transpiration, danger from snow-break, and damage from noxious gases. The evergreen trees have the advantage of lower summer transpiration and are ready at any season of the year for constructive activity. They are also less subject to damage by frost during the growing season. The advent of forestry may change the structure and distribution of our forests. The present tendency seems to be gradually and cumulatively in favor of the conifers. THE AGE OF TREES. Some trees reach great size and enormous age while others re- main small and die young. The size and age which a tree attains depend upon the inherent tendency of the species and the factors of the environment. Some species which naturally grow tall and be- come old may remain small under unnatural and unfavorable growth conditions. Other species never become large and old even under the most favorable growth conditions since it is inborn in them to remain small. A definite age limit cannot be fixed for each species but for general convenience we may classify our common trees as short-lived or long-lived. Of the trees native to the State of Pennsylvania the Oaks, Chestnut, Button wood, Tulip Tree, White Pine, and Hemlock may be regarded as long-lived trees, and the Pop- lars, Willows, most Birches, and some Cherries as short-lived. Some of the White Oaks found in the original forest of Pennsylvania showed an age of approximately 500 years. Some of the trees of this State reach a great age and enormous size, still none approach such 32 trees as the Big Cypress Tree of Tule found in the state of Oaxaca, Mexico, or the Sequoia of California. It is not always easy to tell the age of a tree or that of an even- aged stand of trees. Planting records are often very valuable in determining their exact age. The best means of finding out the exact age of a tree is to ask the owner who kept a record when the tree was planted. This method may be used for some ornamental trees and for forest stands which were artificially established. De- tailed records should be kept of all forest stands whether established artificially or naturally. The determination of the age of trees in the original forest or in an unregulated forest is a more difficult task. The age of a young tree like that of a child is more readily determined than that of an old tree. The best test for telling the age of a tree, if planting records are wanting, is to count the an- nual rings on a cross-section of the stem near to the ground and adding to this number, as many years as it took the tree to grow to that height. (Plate I, two lower series of drawings, and Plate XI, 1, 3). Each ring usually represents the growth of one year. A sec- ond test will apply to such species as White Pine, which develop their lateral branches in distinct and rather regular whorls. (Plate I, upper right figure, and Fig. 19). Each whorl normally represents a year's growth. If the branches have fallen off one can often find the scars of the branches on the stem. (See Frontispiece and Figs. 25 and 26). The age of young trees or small branches can also be determined by counting the rings of terminal bud-scale scars (Plate I, upper left figure). The portion of the branchlet from the end down to the first ring of bud-scale scars represents the last season's growth while that between the first and second rings represents the next to the last season's growth and so on. To tell the age of trees may sometimes be difficult but it is usually fascinating. After you have been successful in determining the age of a few trees, you may find yourself questioning the age of others as you walk or drive by them. A careful study of their growth will often indicate the successes and failures which they met during their development, since a relatively narrow ring often indicates a struggle, while a wide ring often indicates favorable growth conditions. THE FORM AND STRUCTURE OF TREES. 1. FORM : By form is meant the general appearance of a tree. One can study the form of deciduous or broad-leaved trees best in winter when they are devoid of their foliage. After one is familiar with the general form of different trees it is possible to distinguish the different species even at a great distance. The form, together with PLATE I. THE AGE OF TREES. Fig. 34. OPEN GROWN PINES. " ° ' B"1 ™ eMurrOTt and developed in same envir- 01 per- u tnen repeatedly subdivides Such a trunk i« known as a deliquescent trunk. k ls Fig. 36. FORM OF LOMBARDY POPLAR. Fig. 37. FORM OF WEEPING WILLOW. Fig. 38. FORM OF A YOUNG PIN Fig. 39. FORM OF AN OLD PIN OAK. OAK. Fig. 40. FORM OF A SASSAFRAS. Fig. 41. FORM OF A YOUNG OPEN GROWN TULIP TREE. Fig. 42. FORM OF A RED PINE. Fig. 43. FORM OF A TABLE MOUN- TAIN PINE. It developed in a closed stand. Diameter 22 inches. 33 the color and figure of the bark, is a character by which many of our trees may be accurately distinguished. The form of trees varies with the species, the environment, and the sylvicultural treatment. Some trees attain an enormous size and great age while others never become large or old. The Sequoias of California, also known as Redwoods and Big Trees, and the Cypress trees of Mexico have representatives which are regarded the largest and oldest in exist- ence. A section of a Big Tree now in the American Museum of Natural History in New York City shows that the tree when cut was 1,341 years old. It was 90 feet in circumference at the base, over 050 feet in height, and estimated by lumbermen to contain 400,000 board feet of lumber. Probably the largest Cypress tree in the world stands in a churchyard about five miles from the City of Oaxaca in Mexico. This tree has a circumference, according to recent ineas urements, of 154 feet 2 inches, 6 feet above the ground. It is about 125 feet high and, according to various estimators, can scarcely be less than 4,000 years old, and may possibly be over 5,000 years. Specimens of this size and age have never been found in the State of Pennsylvania. Some of our native trees, the Chestnut, White Oak, Red Oak, Tulip Tree, Hemlock, and White Pine have, however, at- tained great size. A few large specimens which were cut in recent years, showed by count of their annual rings that they had started life before Columbus discovered America. In Forest Leaves, Vol. IX, No. 10, Dr. J. T. Eothrock describes a White Oak standing near Kutztown, Berks county. It was 31 feet in circumference at the level of the ground and had a spread of branches of 104 feet and an estimated height of almost 74 feet. This tree was probably the largest of this species in Pennsylvania. Larger specimens of Chest- nut have been found in this State. The largest Chestnut tree on record had a diameter of 17 feet. It was found near Waynesville, North Carolina. Other species like the Scrub Oak (Fig. 4), Gray Birch (Figs. 64 and 69), and Scrub Pine never become large. Some species may remain small in one region and yet become large in another. The Chinquapin which reaches its northern limit in Penn- sylvania seldom exceeds a height of 10 feet in this State while it reaches a height of 50 -feet in southern Arkansas. The character of the stem, to a large extent, determines the form of the tree. The main axis of a tree usually grows erect. The lateral branches vary according to the species and the position of neighbor- ing branches. In some species like the Weeping Willow (Fig. 37) they are drooping, in others like the Black Gum and Pin Oak (Fig. 38) they are horizontal, while those of the Lombardy Poplar are ascending (Fig. 36). If the terminal shoot is removed or killed a lateral branch in time may take its place. Sometimes two lateral 34 branches strive for the leadership but they are such close competitor* that neither can win out. The result is a "stag-headed" tree. Again a dormant bud may be stimulated into activity with the result that no lateral branch obtains the leadership. After studying these growth forms, one is inclined to think that the terminal shoot pre- vents the erect growth of the lateral branches. Environment has a marked influence. The form of a tree growing on an exposed mountain top differs very much from one growing on sheltered bottomland. An open grown tree has a form entirely dif- ferent from one grown in dense forest stand. The form of open grown specimens varies with the species. Two different species of Pine shown in Fig. 34 grew side by side in the same environment and still developed entirely different crowns. Open grown trees usually branch near the ground and have a broad, deep, symmetrical crown, while trees grown in dense forest stand usually branch far- ther from the ground and have a long clean trunk with a shallow and often irregular and unsymmetrical crown. Trees grown in a dense stand may not be so attractive as those grown in the open but they yield a much higher grade of wood, since the lateral branches which produce many of the knots in lumber are removed early in the life history of the tree. The density of the forest stand should be so regulated that on every acre of soil not only the greatest quantity but also the best quality of wood is produced. Two kinds of branching are usually recognized, the excurrent or upright and the deliquescent or spreading. When the main trunk is continuous and extends upward to the tip without dividing it is known as excurrent, and when the main trunk is not continuous but divides and subdivides into more or less equal parts it is known as deliquescent. Most of our evergreen species have the excurrent type of branching, while most of our deciduous trees have the deliques- cent type. A few of the latter, as the Pin Oak, Tulip Tree, and But- tonwood, often show an excurrent or upright tendency in the form of their trunk, especially when young. 2. BARK : If we examine the growing point of a seedling we will find that there is very little difference among the parts composing it. Soon, as a result of growth, various kinds of tissue will be formed. At the end of its first growing season we can differentiate roots, stem, and leaves. The stem is still further distinguished into pith, wood, and bark (Plate XI, 1.) Nature seems to know that the vital elementi in the stem need protection. This protection is given by the bark. Bark is that portion of the stem which lies outside of the cam- bium layer. It consists of an outer and an inner part. The former is commonly known as the outer or dry bark and functions primarily Fig. 44. WHITE PINE. Trunk 25 incheg in diameter. Fig. 45. RED PINE. Trunk 20 inches in diameter. Fig. 46. PITCH PINE. Trunk 22 inches in diameter. Fig. 47. YELLOW PINE. Trunk 29 inches in diameter. Fig. 48. JERSEY OR SCRUB PINE. Trunks 7 and 14 inches in diameter. Fig. 49. AMERICAN LARCH. Trunk 18 inches in diameter. Fig. 50. BALSAM FIR. Trunk 16 inches in diameter. Fig. 51. BLACK SPRUCE. Trunk 14 inches in diameter. Fig. 52. RED CEDAR. Trunk 24 inches in diameter. Fig. 53. HEMLOCK. Trunk 22 inches in diameter. Fig. 54. AMERICAN HOP HORN- BEAM. Trunk 18 inches in diameter. Fig. 55. RED MULBERRY Trunk 17 inches in diameter. Fig. 56. REDBUD. Trunk 8 inches in diameter. Fig. 57. BUTTON WOOD. Trunk 18 inches in diameter. Fig. 58. SWEET BUCKEYE. Trunk 32 inches in diameter. Fig. 59. HONEY LOCUST. Trunk 30 inches in diameter. Fig. 60. RED MAPLE. Trunk 8 inches in diameter Fig. 61. RED MAPLE. Trunk 30 inches in diameter. Fig. 62. SUGAR MAPLE. Trunk 32 inches in diameter. Fig. 63. STRIPED MAPLE, Trunk 4 inches in diameter. Fig. 64. GRAY BIRCH. Trunks 4-9 inches in diameter. Fig. 65. RIVER BIRCH. Trunks 6 inches in diameter, Fig. 66. SLIPPERY ELM. Trunk 26 inches in diameter. Fig. 67. SASSAFRAS. Trunk 26 inches in diameter. Fig. 68. YELLOW BIRCH, Trunk 8 inches in diameter. Fig. 69. GRAY BIRCH. Trunk 4 inches in diameter. Fig. 70. BLACK BIRCH (Young.) Trunk 7 inches in diameter. Fig. 71. BLACK BIRCH (Old.) Trunk 27 inches in diameter. Fig. 72. RED OAK. Trunk 46 inches in diameter. Fig. 73. WHITE OAK Trunk 30 inches in diameter. Fig. 74. BLACK OAK. Trunk 42 inches in diameter. Fig. 75. ROCK OAK. Trunk 34 inches in diameter. Fig. 76. PIN OAK. Trunk 15 inches in diameter. Fig. 77. SWAMP WHITE OAK. Trunk 32 inches in diameter. Fig. 78. SCARLET OAK. Trunk 14 inches in diameter. Fig. 79. BASS WOOD. Trunks 8-14 inches in diameter. Fig. 80. BUTTERNUT. Trunk 20 inches in diameter. Fig. 81. BLACK WALNUT. Trunk 24 inches in diameter. Fig. 82. CHESTNUT. Trunk 62 inches in diameter. Fig. 83. BLACK LOCUST. Trunk 18 inches in diameter Fig. 84. TULIP TREE. 'nink 21 inches in diameter. Fig. 85. CUCUMBER. Trunk 26 inches in diameter. Fig. 86. WHITE ASH. Trunk 30 inches in diameter. Fig. 87. BLACK ASH. Trunk 22 inches in diameter. Fig. 88. SHAG-BARK HICKORY. Trunk 26 inches in diameter. Fig. 89. PIGNUT HICKORY. Trunk 22 inches in diameter. Fig. 90. MOCKER NUT HICKORY Trunk 18 inches in diameter. Fig. 91. BITTER NUT HICKORY. Trunk 24 inches in diameter. Fig. 92. BEECH. Trunk 30 inches in diameter. Fig. 93. AMERICAN HORNBEAM. Trunk 6 inches in diameter. Fig. 94. HONEY LOCUST. Trunk 10 inches in diameter. Fig. 95. LARGE-TOOTHED ASPENS. Trunks 16 and 18 inches in diameter. Fig. 96. WILD BLACK CHERRY. Trunk 6 inches in diameter. Fig. 97. WILD BLACK CHERRY. Trunk 18 inches in diameter. Fig. 98. DOMESTIC CHERRY. Trunks 12 and 14 inches in diameter Fig. 99. TREE OF HEAVEN. Trunk 12 inches in diameter. Fig. 100. BLACK GUM. Trunk 22 inches in diameter. Fig. 101. PERSIMMON. Trunk 12 inches in diameter. Fig. 102. HACKBERRY. Trunk 8 inches in diameter. Fig. 103. FLOWERING DOGWOOD. Trunk 6 inches in diameter. . . . . • .•• .•••*:: •••"•*•••• •••• ••••£•* »••••" ••••• 35 as a protective covering while the latter is known as the inner or living bark and helps to convey the food which was manufactured in the leaves to various parts of the stem. Thickness of the bark is often determined by the rapidity with which it peels off. Its thickness, together with its larger number of dead, air-containing cells, makes it a very effective protective covering; but the chief protective feature of bark is the formation of corky layers. The chief function of the protective covering in plants is the prevention of excessive transpiration. The regular cork formations in the bark help very much in controlling transpiration. Cork is one of the most valuable elements of the bark. Its structure is complex and vari- able. Cork is impermeable to air and water, a poor conductor of heat, and a preventer of penetration by parasites. Local out-growths of cork like the wings of the Sweet Gum and Hackberry are prob- ably of no value to the plants producing them. In some species the bark is not fully "ripened" at the end of the growing season, con- sequently the subjacent tissues do not have the necessary protection and frequently die back during the winter. The color of the bark varies in different species, in different situations, in different parts of the same species, and with the age of the trees. Young bark is usually green, but it soon loses this color due to the formation of cork and other substances. A few species like Sassafras retain their green color for a relatively long time due to deferred or late cork formation. Gray, brown, and black are the prevailing bark colors while red and white are also common. Color of the bark is very helpful in distinguishing many of our common trees. All the species of Birch native to Pennsylvania may be distinguished from each other by the color of their bark together with a few other bark char- acteristics. The bark on some of the older trunks becomes rough and then the characteristic color of the species may be present only on the branches and young stems. The outer bark may be uniform, mottled, or variegated in color. The interior and exterior parts of the bark may differ in color. Black Oak bark is yellow within and black without, while Hemlock is reddish within and brown to black without. The bark of the Button wood is peculiar since it is dark brown without and green, yellow, or white within. The inner bark often becomes very conspicuous due to the complete peeling off of the outer bark. Young branches and stems are usually smooth since the bark ex- pands sufficiently to accommodate the increased diameter growth of the interior. Later, in most species, the bark begins to crack, since the growth of the interior is too rapid for the expansion of the bark. In a few species like Beech, Blue Beech, and Balsam Fir the bark remains thin and smooth throughout life. Other species like Basswood and Pin Oak remain smooth for a long time but be- come furrowed later, while many other species become rough early in life. The manner in which the bark cracks open or peels off af- lords a ready means of identification for many of our trees. The exfoliation of the bark is rather constant for each species. In some species like the Yellow Birch and Paper Birch it peels off in thin film-like papery layers. In the Shag-bark Hickory it is shaggy; in many species like the Pines and Spruces it is scaly ; while in others like the White Cedar it is shreddy. Many species have furrowed bark. The furrows run usually in a longitudinal direction but may run transversely. The furrows or fissures separate ridges. These vary with the species. The fissures may be short or long, close or distant, narrow or wide, longitudinal, transverse, or diagonal. The ridges may be pointed or broad, high or low, smooth or scaly. The bark may be broken up into small square or rectangular blocks as in the Black Gum. This form of bark is often spoken of as "alli- gator bark." See Figures 44-103 for bark of most of our important native trees. The bark may be of considerable technical value. Hemlock and some species of Oak and Spruce have bark which is rich in tannin. The bark of these species is used extensively in the leather industry. The bark of a European species of Oak is highly prized on account of the large quantity of cork which it produces. The inner bark of some species yields dyeing material while that of others is used in the manufacture of fibre cloth. Formerly the bark of the Paper Birch was used in the construction of canoes. 3. TWIGS : Twigs are the terminal parts of branches. The term twig usually refers to that portion of the terminal part of the branch which grew in the last season. Those portions of the branch which began their growth a few seasons ago are usually spoken of as older twigs or branchlets. The twigs have their origin in the vegetative buds which may be located on the terminal end of the twig of the previous season's growth or along its side. If they emerge from terminal buds they become leaders, and if from lateral buds they will develop into lateral branches. The lateral branches may be 'alternate, op- posite, or whorled (Plate II) . The method of branching is very help- ful in distinguishing our common trees. The lateral branches of most of them alternate with each other, while a fair number are opposite and a few whorled. The terminal twig elongates rapidly while the lateral ones usually remain shorter and occasionally are compressed to a stub or spur. When the vegetative buds burst open in spring young twigs, which are often covered with developing leaves, emerge from them. These twigs are, at first, usually delicate, greenish in color, and PLATE II. TYPES OF TWIGS AND PITH. 1. Tulip Tree (alternate branching). 2. Catalpa (whorled branching). 3. White Ash (opposite branching). 4. Gray Birch (slender and warty). 5. Staghorn Sumach (hairy). 6. Elderberry (lenticels prominent). 7. Black Cherry (lenticels transversely elon- gated) . 8. Chestnut (lenticels small and numerous). Drawings are about one-half natural size. 9. Black Gum (lenticels few and inconspicuous). 10. Black Walnut (chambered pith). 11. Sumach (large pith). 12. Sassafras (medium-sized pith). 13. Oak (star-shaped pith). 14. Black Alder (triangular pith). 15. Common Locust (angular pith). 16. Elm (circular pith). 17. Birch (semicircular or irregular pith). PLATE III. TYPES OF BUDS. 1. Sugar Maple (opposite). 2. Chestnut (alternate). 3. Butternut (superposed). 4. Red Maple (accessory). 5. Striped Maple (stalked). 6. Striped Maple (valvate). 7. Red Oak (scaly). 8. Buttonwood (sub-petiolar) . 9. Beech (solitary terminal). 10. Black Oak (clustered and hairy terminal). 11. Basswood (axillary and pseudo-terminal). 12. American Elm, showing (1) leaf buds and (f) flower buds. 13. Papaw (naked flower- and leaf -buds). 14. Common Locust (imbedded). 15. Trembling Aspen (sharp-pointed). Drawings are about one-half natural size. 37 often hairy. As they develop during the season they become firmer and often lose their green color and their hairs. The direction of the new growth is variable. In many species it takes at first a drooping direction and later, as its elements become firmer, it as- sumes a horizontal or ascending position. The new growth of the Pines is conspicuous in that it grows in an erect direction at first and later becomes horizontal or drooping. The taste, smell, and color of the twigs, are helpful in distinguish- ing some of our common species. The twigs of some species as the Black Birch, Spice Bush, Sassafras, and Wild Cherry have a char- acteristic taste and smell. The color of the twigs may be green as in the Sassafras, red as in the Basswood and Red Maple, or brown as in the Sugar Maple. Many other different colors and combina- tions of color aid materially in distinguishing our trees. Some twigs are rough while others are rather smooth. They may be roughened by hairs, lenticels, raised leaf-scars, bud-scale scars, warty or resinous exudations, corky projections, or decurrent projections of the bark. If we examine a young twig just after it has emerged from the bud we will find that it is usually green in color. At the end of the first season's growth a thick bark has usually developed which is no longer green on the surface, but, by cutting a cross section of a twig, one will often find that the inner bark is still green. This green tissue develops chlorophyll and manu- factures food just as* does the green tissue of the leaves. As the bark increases in thickness the chlorophyll decreases, eventually dis- appearing entirely from the stem. In order that this green tissue in the bark may function it is necessary that gases be exchanged through the bark. Special structural modifications on the bark known as lenticels (Figs. 96 and 98) make possible this exchange of gases just as the stomata on the leaf-surfaces allow and even regu- late the exchange of the gases of the leaf. The lenticels are very numerous and conspicuous on some species, while on others they are rare and inconspicuous. They are raised on some species like the Elder, while on others they are even with the bark. Their color varies. They may be white, gray, pinkish, yel- low, brown, or black. In outline they are usually circular or slightly elongated. In the Cherries and Birches they are confluent, a char- acteristic which results in the horizontally elongated lines of lenti- cels (Figs. 96 and 98) so common on their trunks. The duration of the lenticels varies with the species and its en- vironment. As a rule the more rapidly bark is formed the shorter is the duration of the lenticels. On some species it is difficult to find lenticels on any but the last season's growth while on others they may persist for some years, The exfoliation of the bark causes their disappearance. On a few species like the Birches, Cherries, and Honey Locust they persist for many years. The distribution of lenticels has not yet been systematized. They are distributed rather uniformly over the newer growth but are ir- regularly spaced. In some species they seem to be somewhat clus- tered just below the nodes and in others like Honey Locust they are more numerous on the lower side of horizontal branches. The pith usually occupies the central portion of twigs, branchlets, and roots. It is composed of thin-walled cells which are loosely ag- gregated. It seldom increases in size after the first year. The pith of a tree 100 years old is usually not wider than that in a year old twig of the same species. It becomes functionless early in the life of a tree. The pith of conifers is rather uniform in outline, structure, and color, but in the broad-leaved species it is very variable. In most species it is small in proportion to the size of the twigs, but in a few species like Sumach, Elder, Sassafras, Ailanthus, and Kentucky Coffee-tree it is relatively large. The outline in cross section may be 5-angled or star- shaped as in the Oaks, Chestnut, and Aspens, 3-angled as in Alder and some Birches, angular as in Common Locust, circular as in Elm, and ovoid as in Basswood. As a rule the pith is continuous, but in a few species like Black Walnut, Butternut, and Hackberry it is chambered. A few species like Catalpa have continuous pith except at the nodes where it is sometimes chambered. A less distinct separation of the pith is found in Black Gum, Papaw, Tulip Tree, and the Magnolias where plates of stone cells occur. The color of the pith may be white as in the Sugar Maple, pinkish as in Red Maple, brown as in Striped Maple, Mountain Maple, Sumachs, and Walnuts, red as in Kentucky Coffee-tree, or greenish as in Shad Bush. 4. BUDS : In temperate and colder climates the growing season extends over a part of the year only. During the warmer part of the year vegeta- tion is active, but as soon as the weather becomes cooler, many an- nual plants die while others make special preparation for the win- ter. One of the preparations is the formation of buds. They are formed in most trees and shrubs of cold and arid climates. If we examine a twig from one of our common trees in the month of July we can usually find buds starting to develop in the axils of the leaves. They continue to develop until they have reached a certain size, and then remain in an inactive condition for a few months in winter, only to become active again when favorable growth condi- tions return in spring. A year usually includes a period of rest alternating with a period of activity. Buds may be divided into 39 two classes, active and resting. Active buds are growing or develop- ing buds, such as one finds in late summer prior to the period of rest and early in spring when the resting buds have been awakened from their winter's slumbers. The resting buds are commonly known as winter buds (Plate ITT). Buds are protected growing points. The degree of protection given to the growing points varies with the species. A few of our trees and shrubs have buds which are nearly or quite destitute of a scaly covering. These are know as naked buds. The protection usually consists of scales which may be supplemented by hairy out- growths, resin, gums, or air spaces. These are known as scaly buds. The buds may be covered by numerous overlapping scales, known as imbricated bud-scales, or they may be covered by simply one or two visible scales which do not overlap. The buds of the Willows and Buttonwood are covered by a single visible bud-scale, while the buds of such species as the Striped Maple and the Black Alder have only two visible bud-scales whose margins simply meet and do not overlap. The latter are known as valvate buds. The buds may also receive protection from the enlarged bases of the stalk of leaves which often persist far into winter. The buds covered by the en- larged base of the leaf-stalk are known as subpetiolar buds. The buds of some of our common trees are very inconspicuous. It is often difficult to locate them when sunken so deeply into the bark that only the tip is visible. The size of the buds is not indicative of the size of the flowers or leaves which they will produce the fol- lowing season. Many of the trees which bear small and inconspicuous buds produce large and conspicuous flowers and leaves. The prin- cipal functions of the protective covering of buds are the prevention of the loss of water from the tender parts within and the protec- tion of their delicate interior from mechanical injury. Some add that the protection also minimizes the damaging effect of sudden temperature changes. The position of buds is of considerable value in distinguishing many of our trees and shrubs. They may occur at the end of the twigs or along their sides. The former are known as terminal buds and the latter as lateral buds. The terminal buds may be solitary as on the Beech or clustered as on the Oaks. On most of our trees and shrubs the lateral buds appear just above the origins of leaf- stalks and are known as axillary buds. They may occur in pairs, one on one side of the twig and the other exactly opposite, or singly forming a spiral around the twig. The former are known as opposite buds and the latter as alternate buds. The axillary buds may occur solitary or in groups, either one above the other, or side by side. If they occur one above the other they are known as super- posed buds and if they occur side by side they are known as accessory 40 buds. Sometimes axillary buds remain inactive for a long period of time without losing their vitality. Such are known as dormant buds. During their dormant period they remain on the surface of the trunk by the elongation of their connection with their point of origin. A superabundance of food, excessive light, or the death of a great number of terminally located buds, may stimulate them into activity again. A great number of these buds are often found along the stem of such species as Chestnut and Rock Oak. They develop into short branches which are known as "water sprouts." Some buds are produced at rather unusual points, and in irregular positions along the stem, and are called adventitious 'buds. They also form "water sprouts." One finds a wide variation in the size and form of the buds which our common trees produce. Some are long and slender; others are short and stout. Some of them are round in cross-section; others are angular. Some are sharp-pointed; others are blunt-pointed. The buds also vary in the manner of their insertion on the twigs. Some are inserted directly on the twig; others are separated from the twig by a stalk, and still others may be almost entirely covered by the twig. The former are called sessile buds, the next stalked buds, and the latter imbedded buds. The kind of buds which a tree produces is of considerable import- ance, especially where fruit trees are considered. Three principal kinds of buds may be distinguished: — leaf buds, also known as vege- tative buds, the contents of which will develop into stem and leaves; mixed buds, the contents of which consist of leaves and flowers in their formative stage; and flower buds, also known as propagative buds, which contain the elements of flowers only. How can one find out what kind of buds are at hand? The buds may be cut open by means of a sharp knife and their contents studied with the aid of a magnifying glass. One may also take a twig and place it in a jar of water in a warm room and in about a week the buds will have expanded far enough to reveal the nature of their contents. The twig with its buds may also be left on the trees and its development observed in spring when nature opens them. With all this varia- tion in the position, insertion, form, structure, and kind of buds we still find here, as in all nature, law and order. 5. LEAVES : The shoot of a seed plant consists of stem and leaves. The leav- of our common trees are excellent distinguishing characters by which the species may be recognized. They are variable in form. This variation, as well as the work they do, is little appreciated by the crowds which annually seek their shade and shelter. This chapter PLATE IV. TYPES OF LEAVES. 1. Black Cherry (simple). 2. Common Locust (compound). 3. Chestnut (alternate arrangement). 4. Sugar Maple (opposite arrangement). 5. White Pine (5-clustered). 6. Pitch Pine (3-clustered). 7. Jersey or Scrub Pine (2-clustered). 8. Larch (many clustered). 9. Larch (many clustered at base; solitary on leading shoots). Drawings are about one-half natural size. 10. Red Spruce (4-sided). 11. Balsam Fir (flat and sessile). 12. Hemlock (flat and stalked). 13. Red Cedar (scale-like needles). 14. Arbor Vitae (scale-like needles). 15. Arbor Vitae (section enlarged showing glands on leaves) . 16. Red Cedar (awl-shaped needles). Bnsf/e -pointed £nt/re Dentate Cac.roe/y-jerrtrte Oerrafe PLATE V. TYPES OF LEAVES. 41 aims to give a general description of leaves and a brief outline of their work. A typical foliage leaf consists of three parts: (1), the blade or flattened portion (lamina) ; (2), the leaf-stalk (petiole) ; and (3), the leaf -appendages (stipules). Two kinds of leaves are usually recognized: — simple and com- pound (Plate IV). Simple leaves have blades which are more or less united into one piece, while in compound leaves each leaf is composed of a number of smaller leaflets. Compound leaves may have all the leaflets originate from one point as in the Buckeyes (Plates CXII, CXIII), or scattered along the main petiole as in the Common Locust (Plate XCVII). Each primary division of a compound leaf may again be compounded as in the Kentucky Coffee-tree (Plate XCIV). Such a leaf is known as a doubly compound leaf. The arrangement of the leaves on the twigs and branches of our common trees may be alternate, opposite, or whorled (Plate IV). When the arrangement is alternate, the individual leaves are located singly at a node; when opposite, two leaves occur opposite each other at a node; and when whorled, more than two leaves occur at a node and are distributed regularly around the twig. In a few species as the Birches, the leaves of the lateral spurs appear to be opposite, but upon closer examination they are found to be alternate. The leaves of the trees native to this State may be classified as follows: (1), Trees with needle-shaped leaves, known as conifers or evergreens, and (2), trees with broad leaves known as hardwoods or deciduous trees. The needle-shaped trees show a wide variation in the form and distribution of their needles. They may occur singly, in fascicles of 2, 3, or 5, or in clusters on lateral spurs; they may also be stalked or sessile, scale-like or awl-shaped, and flat, semi-circular, triangular, or four-sided in cross-section. The broad- leaved trees have an even wider variation in form. This may be in part due to the greater number of representatives belonging to this order. A few of the commonest leaf forms are shown on Plate V. Other intermediate forms are commonly found among our trees. The size- of the leaves varies as much as their form. They may be small, scale-like, or awl-shaped as in the Arbor Vitae and Common Juniper respectively, or large and tropical-like as in the Magnolias and Papaw. The point, or apex, of leaves varies with the species and the gen- eral leaf -form. The commonest kinds of points recognized are shown on Plate V. The bases of leaves are also often characteristic and of consider- able value in distinguishing species, since different species may have the same general form but different bases. The commonest kinds of bases recognized are shown on Plate V. Intermediate forms may 42 readily be found, since leaves taken from the same tree or branch often show a wide variation. The margins of leaves are often more variable than their apexes and bases. The kinds most commonly recognized are shown on Plate V. The figures represent the margins of simple leaves, but the margins of the leaflets of compound leaves follow the same ter- minology. Most of the leaves of our common forest trees contain a rather complicated system of fibro- vascular bundles. These fibro-vascular bundles, known as veins, form the framework of the leaves. Sur- rounding and between these veins is found a green pulpy mass, the spongy parenchyma. The whole body of the leaf is covered by a protective covering known as the epidermis, the thickness of which varies with the species of tree and the climate. One can find variations in the petiole and stipules of leaves as well as in the blade. The petiole may be absent, short, or long. When the petiole is absent the leaf-blade is sessile. It may also be enlarged at the base, circular, heart-shaped, flat, or triangular in outline. The enlarged base may be hollow or clasping. The stipules are usually not very conspicuous. In many species they persist for a short time only and then fall off. The main function of the stipules is protection, but a special modification of the stipules is seen in the Common Locust (Plate XCVII), where the thorns are modified stip- ules and function as mechanical protectors. Leaves are the most industrious organs of a plant. They work day and night from early spring until autumn. The four chief func- tions of leaves are: (1) Photosynthesis; (2) Eespiration; (3) Transpiration, and (4), Assimilation. Photosynthesis is the process by which the leaf manufactures starch or sugar from carbon dioxide and water with the aid of the energy of light. That green plants require light for their growth and development is shown by the man- ner in which the axis and their leaves adjust themselves so as to re- ceive the greatest amount of light. By respiration in plants is meant the process by which oxygen is consumed and carbon dioxide and water are given off. It is primarily a process of oxidation and re- sembles in general the process of respiration as found in- man and higher animals. In order to facilitate this exchange of gases the plants are supplied with openings on the leaf surfaces, especially on the lower surface, and on the bark. The openings on the leaf sur- faces are known as stomata and those on the bark as lenticels. Each slit-like opening on the leaf is surrounded by two guard cells which are somewhat complicated in structure and very' sensitive to changes in temperature and water supply. They function primarily as breathing pores and as outlets for the water vapor given off during the process of transpiration. Their number varies, but it has been PLATE VI. TYPES OF LEAF-SCARS AND BUNDLE-SCARS. 1. Tulip Tree. 2. Catalpa. 3. American Hornbeam. 4. Sassafras. 5. Persimmon. 6. Maple. 7. Poplar. 8. Red Mulberry. 9. Button wood. 10. Chestnut. 11. Walnut. All drawings are slightly enlarged 12. Basswood. 13. Birch. 14. Box Elder. 15. Papaw. 16. Horse Chestnut. 17. Dwarf Sumach. 17a. Staghorn Sumach. 18. Hercules' Club. 19. Sour-wood. 20. Kentucky Coffee Tree. 21. Ash. PLATE VII. FLOWERS AND FLOWER ARRANGEMENT. 1. White Pine (staminate cluster), x J. 2. White Pine (2 pistillate), x J. 3. Willow (staminate ament), x i. 4. Willow (pistillate ament), x J. 5. Walnut (staminate ament) , x i. 6. Walnut (a pistillate flower), enlarged. 7. Hickory (staminate ament), x J. 8. Hickory (a pistillate flower), natural size. 9. Birch (a staminate ament). x J. 10. Birch (a pistillate ament), x J. 11. Beech (a staminate head), x J. 12. Beech (two pistillate flowers), natural size. 13. Chestnut (a staminate ament), x \. 14. Chestnut (a pistillate ament), x J. 15. White Oak (4 staminate aments), x 5. 16. White Oak (a pistillate flower), enlarged. 17. Elm (3 clusters of incomplete flowers), x 1. 18. Mulberry (a staminate spike), x J. 19. Mulberry (a dense pistillate spike)', x J. 20. Tulip Tree (a complete flower), x j. 21. Papaw (a complete flower), x J. 43 estimated that the lower leaf surface of Black Walnut contains about 300,000 per square inch. The leaf is not only peculiarly modi- fied for the reception of light and the absorption of gases, but also for the loss of water. This process of losing water in the form of vapor through the stomata is known as transpiration. The large amount of water given off by trees is usually not appreciated. The Austrian Forest Experiment Station has published data which show that an open-grown birch tree with 200,000 leaves transpired on hot summer days from 700 to 900 pounds. Assimilation, the fourth of the functions named above, comprises a series of changes which are necessary to transform the raw or newly manufactured food material into actual plant tissue. 6. LEAP-SCARS AND BUNDLE-SCARS: Most of our trees and shrubs, except the cone-bearers, shed prac- tically all their leaves in autumn. Those which shed their leaves in this manner are known as deciduous trees, while those which re- tain them for two or more seasons are known as evergreen trees. When the leaf falls a scar is left at the point of its insertion. The leaf-scars vary in size, form, position, occurrence, and the number of vascular bundles which they contain (Plate VI). They may oc- cur singly, in pairs, or in whorls, just as the leaves which precede them. They appear at points on the twigs known as nodes. The portion of the twig between the nodes is called the internode. They may be large, medium, or small in size depending upon the species. If they occur in pairs on opposite sides of the twig they may be so large that they completely encircle the stem, or only a portion of it. Their form may be round, oval, elliptical, heart-shaped, shield- shaped, crescent-shaped, lobed, or triangular. They may be raised, depressed, or even with the surface of the twig. Their surface may be flat, concave, smooth, or wavy. The leaf -scars contain bundle-scars. The bundle-scars mark the position of the vascular bundles which formed a connection between the leaves and the twigs. They carry liquid material to and from the leaves. Two distinct portions may be distinguished in these vascular bundles ; the woody portion which serves to carry water into the leaf, and the sieve- tube portion which serves to carry plant food from the leaves where it was manufactured, down into the twigs, branches, and stem. These bundle-scars vary in size, form, and num- ber in a leaf-scar, and the manner in which they are distributed. Some of our common forest trees have only one bundle-scar in a leaf- scar, while many have three, and others four, five, to many. The number is constant in some species and variable in others. The in- dividual bundle-scars usually are circular in outline but may be linear, crescent-shaped, or irregular. Where more than one is found 44 in a leaf-scar they vary in their arrangement. They may form a closed ellipse, a lunate line, a double line, a V-shaped or a U-shaped line, or they may be irregularly scattered over the leaf-scar, or grouped in clusters. A number of bundle-scars may sometimes be grouped so close together so as to form a compound bundle-scar or a line of confluent bundle-scars. The leaf-scars together with their bundle-scars are excellent characters with which to distinguish many of our common forest trees during winter when most of the distinguishing characteristics which one can use in summer are ab- sent. By carefully studying these characteristics, together with others, it is as easy to distinguish the forest trees in winter as in summer when the foliage is present. 7. FLOWERS : Sometime in their life history plants usually give rise to others of their kind. The method which they use to accomplish this varies with the species or the group. Most of our trees develop flowers whose chief function is pollination, the initial step in the production of seeds. The existence of flowers is consequently for the good of the plant and not for the good of man, even though their beautiful forms and colors do please his fancy and make his life happier. The flowers of our common trees vary considerably in form, struc- ture, and color (Plates VII, VIII). Most of them are very modest in appearance while a few of them are conspicuous on account of their large size and brilliant color. In speaking of the flowers of our trees collectively, one often hears the phrase "The uncommon flowers of our common trees." The truth of this phrase becomes clear when we think of the small and inconspicuous pistillate flowers which such trees as the Oaks, Birches, American Hop Hornbeam, Walnuts, Hickories, and .others produce. A few species like the Magnolias, Cherries, Dogwoods, Tulip Tree, and Basswood produce rather conspicuous flowers. The parts of a flower are of two general kinds — the essential organs which are concerned in the production of seeds and the floral en- velopes which act as protecting organs. The essential organs con- sist of two series, — the outer which is composed of stamens and bears the pollen, and the inner which is composed of pistils and bears the seeds. The floral envelopes also usually consist of two series, — the outer which is composed of sepals, collectively known as the calyx, and the inner which is composed of petals, collectively known as the corolla. The corolla is usually the showy part of a flower while the calyx is usually green in color. A flower which has calyx, corolla, stamens, and pistils is said to be complete. If any part is wanting it is incomplete. When both the floral envelopes are wanting it is naked. A flower in which the pistils are lacking is known as a staminate flower, while one in PLATE VIII. TYPES OF FLOWERS. 1. Sweet Gum (staminate heads), x J. 2. Sweet Gum (a pistillate head), x i. 3. Common Locust (a drooping raceme), x i. 4. Striped Maple (a drooping staminate raceme), x J. 5. Striped Maple (a drooping pistillate raceme), x 5. 6. Red Maple (staminate fascicles), x J. 7. Red Maple (pistillate fascicles), x J. 8. Basswood (a drooping cyme), x J. 9. Flowering Dogwood (a dense cluster), x J. 10. White Ash (a staminate panicle), x i. 11. White Ash (a pistillate panicle), x J. 12. Rhododendron (a single flower), x i. 13. Wild Black Cherry (a raceme), x |. 14. Buttonwood (a head), x |. 14 PLATE IX. TYPES OF FRUIT. 1. White Pine (cone), x 1. 2. White Pine (winged seed), natural size. 3. Willow (capsules), x J. 4. Willow (a winged seed), enlarged. 5. Trembling Aspen (capsules), x J. €. Trembling Aspen (a winged seed), enlarged. 7. Black Walnut (a nut with indehiscent husk), x i. S. Hickory (a nut with dehiscent husk), x J. S. American Hornbeam (a nut with 3 lobed bract), x }. 10. American Hop Hornbeam (a nut inclosed in bladder-like bract), x 1. 11. Black Birch (a membranous strobile), x i. 12. Black Alder (a woody strobile), x J. 13. Beech (a nut with prickly bur), x i. 14. Chestnut (a nut with spiny bur), x 1. 15. R«d Oak (an immature acorn), x i. 16. Red Oak (a mature acorn), x j. 17. Red Mulberry (an aggregate fruit ». « i 45 which the stamens are lacking is known as a pistillate flower. Some- times the staminate and pistillate flowers are not only found on dif- ferent parts of the same tree but on entirely different trees. The chief role of flowers is pollination. Pollination is the transfer of pollen from the anther of the stamen to the stigma of the pistil. When pollen is transferred from the anthers to the stigma of tin- same flower it is known as close-pollination, and when pollen is trans- ferred from the anthers of a flower of one plant to the pistil of a flower of another it is known as cross-pollination. Wind and in- sects are the chief agents which carry the pollen in the case of cross- pollination. The flowers of the Tulip Tree, Papaw, and Cherries, are examples in which close-pollination can take place, while the flowers of the Willows and Poplars are good examples in which cross-polli- nation takes place. When the staminate and pistillate flowers are on the same plants e. g. Oaks, American Hop Hornbeam, Beech, Chestnut, Hickories, and Walnuts, the plants are known as monoecious and when they are on different plants as in the Willows, Poplars, and occasionally some Maples, they are known as dioecious. Flowers vary not only in the size, form, shape of their parts, and color, but also in their arrangement. In a few cases the flowers of trees like the Tulip Tree and Papaw are borne singly and known as solitary flowers. The flowers may also be arranged in clusters like that of the Lily of the Valley or the Wild Black Cherry (Plate VIII, 13). Such an inflorescence is known as a raceme. A raceme may be compact as in the Wild Black Cherry; or loose as in the Common Locust (Plate VIII, 3) and the Striped Maple (Plate VIII, 4-5). When the flower cluster is dense and the flowers sessile, or nearly so, it is known as a spike. Spikes may be 2-5-flowered as in the pistillate flowers of the Hickory (Plate VII, 8), or densely flowered as in the staminate flowers of the Mulberry (Plate VII, 18). A very short and dense spike is known as a head (Plate VIII, 14). A spike is sometimes short, flexible, and rather scaly as in the Willows, Poplars, and rather long as in the staminate flowers of the Oaks, Hickories, Birches, and Alders (Plate VII, 7, 9 and 15). Such a spike is known as an ament or catkin. Other types of inflorescence are the umbels (Plate LXXXVII), panicles (Plate VIII, 10-11), and corymbs. The time at which the flowers appear and their duration varies with the species. The Alders, Hazlenut, and some Maples produce their flowers early in spring before the leaves are out. Others pro- duce them with the leaves, while still others produce them after the leaves. The Witch-hazel produces its flowers late in fall. It is the last of our trees to blossom. 46 8. FRUIT : Sometime after pollination the egg cell or ovule is fertilized, and as a result of fertilization, the ovule, together with the surround- ing ovary, enlarges. The enlarged ovules, together with inclosing ovary, form what is termed the fruit. The fruit may in addition comprise modifications of other organs intimately connected with the ovary. Seeds are products of the flower and are usually regarded as reproductive organs, but in reality they are the result of reproduc- tion. Their chief work is the dissemination and the protection of the offspring of reproduction. They are usually covered by hard and impermeable coats which protect the young plant contained within from the many dangers with which it is beset. Nature tries to guard against these dangers by developing suitable protective cover- ings for each species. Nature, however, is not always satisfied by simply developing a thick and impermeable coat, but in addition it develops an internal tissue which is compact and contains little water. If a seed possess these essentials it is well protected against most of the destructive agencies to which it is exposed. The chief dangers to which seeds are subject are premature germination, loss of vitality, and destruction by animals. Each seed usually has a suitable covering which regulates the germination in spring. This regulation is necessary so as not to allow the tender plant to emerge before the external growth conditions are favorable for its develop- ment. An embryo within a thin-coated seed would often be stimu- lated by a few warm days in spring with the consequence that the resulting tender plants would be killed by later frost. Nature acts as a guardian and places a thick coat around such embryos, and as a result they are not stimulated until later when frost danger is past. Food is stored in various plant organs such as roots, stem, and branches, and is usually most abundant and conspicuous in the seeds. It occurs in various forms and may often differ in composi- tion. Food stored in the seed is very valuable because it supplies nourishment to the small and tender plants before they have de- veloped the roots with which they draw nourishment from the soil and supply water to the leaves where starch and sugar are manu- factured. Primitive man obtained considerable food from the seeds of trees, and present man derives certain foods for himself and his animals from some of our common trees. The food value of seeds varies with the species. Some species like the Willows contain very little food, while others like the Chestnut are rich in food. The time at which the fruit matures varies with the species. Wil- lows, Poplars, and Elms mature their fruits in spring; others, like PLATE X. TYPES OF FRUIT. 1. Osage Orange (a compound drupe), x i. 2. Hackberry (a drupe), x i. 3. American Elm (one-seeded samara), x J. 4. Tulip Tree (a light brown cone composed of many carpels), x i. 5. Papaw (a fleshy or pulpy fruit), x \. 6. Sugar Maple (paired samara), x \. 1. Wild Black Cherry (a drupe), x J. 8. Basswood (a nut-like drupe), x J. 9. Sweet Gum (multicapsular head), x |. 10. Persimmon (a juicy berry), x J. 11. White Ash (samaras), x I. 12. Buttonwood (a head), x J. PLATE XI. THE STRUCTURE OF WOOD. 1. Gross section of six-year old stem of White Pine showing (b) bark, (c) cambium, (ar) annual ring, (p) pith, and (rp) numerous small circular resin passages, natural size. 2. A resin passage with bounding epithelial cells, enlarged. "3. Non-porous wood of White Pine showing (spw) spring wood, (sw) summer wood, (ar) annual ring, and (rp) resin passage, x 3. 4. Ring-porous wood of Chestnut, x 2. 5. Ring-porous wood of Red Oak, showing large medullary rays, x 3. •6. Diffuse-porous wood of Beech, x 4. 7. Block of Chestnut wood showing (cs) cross section, (rs) radial section, (ts) tangential section, (spw) spring wood, and (sw) summer wood, natural size. 47 the Cherries, Mulberries, and some Maples, in summer; but most of them, like the Oaks, Chestnut, Pines, and others, in autumn. The seeds of some species like the Willows die unless they germinate soon after they mature. Most species retain their capacity to germinate for several months or several years, while a few members of the Pulse family are reported to retain their vitality for more than 125 years. The mature fruit and seeds of our common trees show a wide variation in their form and structure. Fruits are usually classified on the basis of their texture, as fleshy fruits and dry fruits. Fleshy fruits are represented by the fruits of such species as Cherries, Papaw, Osage Orange, etc. (Plate X, 1, 2, 5, 7, 10). Dry fruits are those which do not have any flesh or pulp, and are represented by the fruits of such species as the Maples, Ashes, and Oaks (Plate IX, 1-16, and Plate X, 3, 4, 6, 8, 9, 11, 12). Fleshy fruits including the stone fruits, are indehiscent. Indehiscent fruits (Plate X, 1, 2, 5, 7, 10) are those which do not split apart regularly along certain lines for the liberation of the seeds, while dehiscent fruits do split open. Dry fruits may be indehiscent or dehiscent. The following general types of fruits are commonly recognized: the pome (Plate XCII), the drupe (Plate X, 7, 10), the nut (Plate IX, 7, 8, 9, 14, 15), the samara (Plate X, 3, 6, 11), the follicle (Plates LXXVI-LXXVIII), the capsule (Plate IX, 3, 5) and (Plate X, 9), the legume (Plates XCIV-XCVII), the cone (Plate IX, 1) and the collective or aggregate fruits, (Plate IX, 17). The species belonging to a single genus usually produce a common type of fruit, but genera belonging to the same family often have an entirely different kind of fruit. This difference of fruit of genera in the same family is shown very clearly in the Nettle family, to which belong the Elms, Hackberry, Osage Orange, and Mulberry, whose fruit are shown on Plate X, 3, 2, 1, and Plate IX, 17. A wide variation may also occur within the general types mentioned above. The nut is one of the commonest types of fruit found in the forest and will possibly show this wide variation best. Nuts may be small and light, as in the Buttonwood and Birches, or large and heavy as in the Oaks and Chestnut. Light nuts often have appendages attached to them in the form of a membranous wing or a tuft of hairs. The nuts may be produced singly or in strobiles as in the Birches and Alder. They may also be covered or naked. If covered, the covering may be indehiscent and semi-fleshy (Plate IX, 7), or dehiscent and dry (Plate IX, 8). It may also consist of a stalked prickly dehiscent bur (Plate IX, 13), a large spiny dehiscent bur (Plate IX, 14), a bladder-like bag (Plate IX, 10) or a leafy involucre, as in the Com- mon Hazlenuts (Plate LI). In some species the seeds are not cov- ered entirely but simply subtended by a leafy bract (Plate IX, 9). 48 In the Birches aiid Alder the small winged nuts are produced on 3- lobed bracts which are so arranged that they form a cone-like fruit- ing body known as a strobile. It is rather hard to classify the fruits of some species in terms of the types enumerated above, e. g., the fruit of the Basswood has the appearance of a nut, but is in reality a drupe; while the fruit of both the Mountain Ash and the Shad Bush has the appearance of a berry but is actually a pome. A super- ficial examination is often not sufficient to determine the type of fruit. The fruit of our common Sumachs is a drupe, but is usually covered with acid hairs, so that it is difficult to recognize the type of fruit to which it belongs. After the fruits and seeds have been produced, it is necessary that they be scattered on a mineral soil upon which they may germinate. The distance over which they are scattered may be short or long, depending upon the nature of the seeds and the agents by which they are dispersed. The fruit, as a whole, is usually scattered in the case of indehiscent fruits, while the seeds only are scattered in the case of dehiscent fruits. The drawings on Plates IX and X show various structural modifications of fruits and seeds which aid in their dis- persal. The chief dispersal agents are propulsion, man, animals, water, wind, and gravity. The Witch-hazel (Plate LXXXII), is a good example of a species whose seeds are scattered by mechanical propulsion. Man has been distributing seeds for forest trees inten- tionally or unintentionally for many centuries, with the result that the forest structure and landscape in many localities have been en- tirely changed. Many European and Asiatic species have been planted in America, and many of our native species like the Common Locust and White Pine have a wide distribution abroad. Wind is the most powerful of the dispersal agents. Many seeds have special structural modifications which adapt them to be scattered by the wind. The modifications may be a sac-like envelope (Plate IX, 10), a mat of straight capillary hairs (Plate IX, 4, 6) or a membranous winged, or flattened seed (Plate IX, 2 and Plate X, 3, 6, 11). Ani- mals also scatter many seeds. A great number are scattered involun- tarily by animals, especially such seeds as will hang fast to their bodies. Other fruits are juicy and edible and are often eaten by birds and other animals. A large number of our common birds swal- low seeds to get the juicy edible portion surrounding them. These seeds are not injured in passing through the alimentary canal of birds, but in some cases it is thought that the seeds are even bene- fited. The robins, thrushes, and blue birds eat a large quantity of fleshy fruit and should be regarded as valuable agents for dispersing seeds. The blue jay is also an agent that helps to scatter heavy seeds like chestnuts and acorns. Other animals, especially rodents, are also valuable as seed dispersal agents. Water, while not so 49 important as wind, must still be regarded as an agent of seed dis- persal. It transports some seeds over great distances, especially those which will float or are inclosed in bladder-like inclosures like the American Hop Hornbeam (Plate IX, 10), or the Bladder Nut, a small shrub very commonly found along our streams. Gravity on slopes, is a minor agent of seed dispersal, but sometimes does effective work, especially with heavy seeded species like Oak and Beech. 9. WOOD : Wood, next to food, and clothing, is probably the most useful and indispensable material which man uses. It is found in many of the higher plants but becomes of commercial importance only in the sper- matophytes or seed-bearing plants. In the timber-producing trees it is found in the roots, branches, and stems. The wood derived from the roots is limited in quantity and inferior in quality. The branches produce wood which, in some respects, -very closely resembles that of the stem, but is inferior on account of its smaller size, irregular shape, and more knotty structure. The wood obtained from the stem is of the greatest utility and value on account of its desirable dimensions and satisfactory structure. The stem should not only yield- a large quantity of wood but also a superior quality. The quality of wood which a stem will yield depends largely upon its age, inherent ten- dencies of the species, and its environment during its development. High grade material is usually obtained from the stems of valuable species which have attained a large size, are free from lateral branches, and possess little stem taper. The form and character of the stem are dependent on the environment. A suitable environment may be created by applying the fundamental principles of forestry which will not only increase the productivity of our forests but also the quality of the yield. In order to identify the different kinds of woods it is necessary to study them from the following three sections: cross, radial, and tangential (Plate XI, 7). An examination of a cross-section of a woody stem will show that the major part of the structure consists of wood which is covered with bark on the outside and has a narrow cylinder of soft tissue known as pith running through the center (Plate XI, 1). The woody portion of most of our trees, especially the older ones, may be differentiated into two parts on the basis of colors. The central colored part is known as the Jieartwood, while the outer al- most colorless part is known as the sapwood. A narrow zone of cells located between the sapwood and the bark is known as the cambium (Plate XI, 1). All the wood elements have their origin in this zone. For sometime after their origin these elements are living, but later 50 they become functionless and die. The sapwood comprises the peripheral zone of wood which lies next to the cambium and contains the only living elements of the wood. The heartwood comprises all the wood inside of this zone. The elements of the latter are dead and usually dark in color. The line of demarcation between the two regions is usually sharp. The width of the sapwood is variable. In some species like Sassafras it is very narrow, while in other species like Hickory it is wide. The depth of color of the heartwood is also variable. In some species like Persimmon it is very dark in color while in other species like Hemlock there is very little dif- ference in color between the heartwood and sapwood. The cross-section also shows that the wood is divided into numer- ous concentric zones or rings. These are known as annual rings since each one usually represents the growth of a season (Plate XI, 1, 3). Certain disturbances like frost, drought, and insect damage may cause the formation of a second ring in the same season. These rings are known as false or fictitious growth rings. Growth rings have a physiological origin. They represent alternating periods of rest and activity, and occur in practically all trees of the temperate region, characterized by an active vegetative period in summer and a resting period in winter. As one approaches the equator the growth rings disappear, since the seasonal changes are not so sharp. Each growth ring may be divided into two parts, the inner, called early or spring wood, and the outer, called late or summer wood (Plate XI, 3). The cross-section further shows radial lines crossing the growth rings at right angles. These are known as medullary or pith rays, or simply as rays. A few of them originate in the pith and extend through the wood into the bark. Such are known as primary rays. As the stem increases in size additional rays are necessary. These originate in the wood, extend into the bark and are known as sec- ondary rays. The rays are very valuable in distinguishing the wood of many of our common trees since the different woods possess rays which vary in height, width, and structure. The very wide rays of the Oaks enable one to distinguish their wood from that of all other species. These large rays are a valuable asset to Oak wood since they give rise to the beautiful figure which one finds on some oak furniture and interior finishings. The best figure is obtained by quarter-sawing i. e. cutting it radially. The end of a freshly cut log of pine is often covered with small drops of resin, which were given forth from small openings in the wood. These openings are known as resin ducts (Plate XI, 1, 2). They are long intercellular channels bounded by a layer of epithelial cells. Their presence in the wood. of the Pines, Larches, and Spruces enables one to distinguish them from all other trees. Injury may 51 sbmetimes stimulate the formation of abnormal resin ducts in woods in which they do not occur normally. In some woods elements occur, known as vessels, which facilitate the transportation of water in the stem. Their presence or absence and their structure and distribution are among the most valuable characteristics in classifying woods. On the basis of porosity one may divide the woods into three classes, viz: (1) Ring-porous or Unequal Pored, (2) Diffuse-porous or Equal Pored, and (3) Non- porous. Chestnut and Oak wood are excellent examples of the ring- porous class (Plate XI, 4, 5). A zone of large pores is found in the early wood and smaller pores in the late wood. Maple and Beech are common examples of the diffuse-porous class (Plate XI, 6). The pores of this class are approximately of the same size and distributed uniformly throughout the growth ring. Pine and Hemlock are com- mon examples of the non-porous class in which pores are entirely absent. (Plate XI, 3). The wood of this class is also classified as Homogeneous, while that with pores is classified as Heterogeneous. The various woods possess other characteristics which are valu- able in distinguishing them and in using them in the arts. The wood of the different species varies almost as widely as do their flow- ers, fruits, and leaves, especially with reference to grain, weight, hardness, color, gloss, smell, shrinkage, durability, penetrability, etc. These variable properties and the manifold uses to which the different woods are put are discussed under each species. (52) PART II. MANUAL OF PENNSYLVANIA TREES. The Identification, Tabulation, and Description of Species. (54) MANUAL OF PENNSYLVANIA TREES. IDENTIFICATION OP SPECIES. NAMES OF TREES: Trees have two kinds of names, common and scientific. Some species of trees have only one common name while others may have as many as thirty. The same species of tree may have one common name in one locality and an entirely different one in another locality. The Pitch Pine described on page 71 is known in some parts of this State as Jack Pine and in other parts as Nigger Pine. The common name given at the top of each descriptive page is the proper common name and the one used throughout this publication for that particular species. Under the heading "Distinguishing Characteristics," other common names are given. Since Linnaeus published his "Species Plantarum" in 1753, plants have been known by scientific names. These names, as a rule, consist of two parts, the generic and the specific, as is shown by the following species of trees: — Pinus Strobus, Quercus alba, Fraxinus americana, Acer rubrum. The first or generic part refers to the genus and corresponds to a surname. The second or specific part re- fers not to a group of plants but to a particular kind and corre- sponds to the Christian name of a man. The White Pine, Red Pine, and Pitch Pine are different kinds of pines. They belong to the same genus or group and hence have the same generic name, Pinus. Each one, however, is designated by a different specific name. For example, the White Pine is known as Pinus Strobus, the Red Pine as Pinus resinosa, and the Pitch Pine as Pinus rigida. Closely re- lated species are placed in the same genus and closely related genera (plural of genus) in the same family. Such closely related trees as the Pines, Spruces, Firs, and Larches, are placed in the Pine family— Pinaceae. At the time when plants first were studied seriously the Latin language was the one used most commonly to preserve knowledge. The plants consequently were given Latin names. The giving of Latin names to plants and animals has continued down to the present time and no doubt will continue. In the Latin language one finds that plant-names have gender, and that the termination differs (55) 56 in each gender. The specific part of the name must agree in gender with the generic part. The generic name Quercus is feminine, hence the Red Oak is known as Quercus rubra while the generic name Acer is neuter, hence the Red Maple is known as Acer rub rum. The scientific names used in this publication are those found in the Seventh Edition of Gray's Manual of Botany, and are in keeping with the rules of nomenclature laid down at a Congress in Vienna. On account of the present unsettled condition of our nomenclature it is often possible to find a certain species designated by two or more dif- ferent scientific names, e. g., the Scrub or Bear Oak is known as Quercus ilicifolia, Wang.; Quercus nana, Sarg.; or Quercus pumila, Sudw. The authorized scientific name is given at the top of each descriptive page, and where other scientific names are in common use, they are given as synonyms just below the authorized one or in the description. The mere knowledge of the names of trees is of little value or satisfaction. The name is simply a means by which to come nearer to the plant. Learning the names of trees serves about the same purpose as learning the names of persons. It is merely an introduc- tion which allows us, in fact often stimulates us, to become more intimately acquainted with their life-processes, associations, en- vironments, and commercial importance. EXPLANATION OF TERMS AND HEADINGS: Some readers no doubt will find terms in this publication whose meaning they do not know. Some of the terms have been discussed at length in Part I while others will be defined in a glossary follow- ing the description of the species. The description of the species of trees contained in this publication is subdivided into a number of headings. Most of these headings are discussed at length in Part I. The significance and scope of those headings not discussed in Part 1 will follow at this point. Under the several headings is given such descriptive material which will be of value not only to the student of Dendrology but also to the layman who may know little concern- ing the characters and habits of trees. The headings have been so selected and treated that one should be able to identify our com- mon trees at all seasons of the year. Under the heading "Distinguishing Characteristics" aj*e given both general and specific characteristics by which the species can be recognized. The species are usually compared with other rather closely related ones with whicK they might be confused. The dis- tinguishing characteristics and comparisons are based upon the trees native to Pennsylvania, and consequently do not embrace other closely related species found outside of the State. 57 The headings "Range" and "Distribution in Pennsylvania" are often of special importance on account of their identificational value. Many species of trees have a limit to their geographical distribution in this State, and by knowing this accurately one is often able to identify a species by the process of elimination. The Sweet Buckeye and Fetid Buckeye are found only in a few counties in the western part of the State. The Red Pine and Paper Birch are found only in the northern part, while the White Cedar is found only in a few counties in the extreme southeastern part of the State. If one finds a birch tree growing in the forest in the southern part of the State, he can feel certain that it is not Paper Birch, because this is beyond the southern limit of this species. A coniferous tree growing wild on the top of the South Mountains in Franklin county, Pennsylvania, must be a Pine, Hemlock, or Red Cedar, because no other coniferous trees grow there. Further we know that it cannot be the Red Pine, because this species does not extend so far south in the State, and on the basis of habitat we can also be reasonably sure that it is not the Yellow Pine, the Jersey or Scrub Pine, nor the Hemlock, because they very seldom ascend to the tops of the mountains, but usually re- main at lower elevations. Likewise, if a maple tree is found at the same place we know that it is the Red Maple or Mountain Maple because they are the only Maples found in that particular locality. If Magnolia trees are found in Centre county one can be certain tha t the species is not Laurel Magnolia, (Magnolia virginiana), because this species has its western limit of geographical distribution at Caledonia, near Chambersburg, Franklin county. The habitat also aids considerably in identifying various species. A birch tree found growing upon a mountain slope or mountain top is rarely the River Birch, because the latter usually frequents moist locations like banks of streams and lakes. Chemical composition of the soil also influences distribution. A soil rich in lime seldom has Chestnut growing upon it, at least in stands, while other species seem to thrive upon such soil. No doubt at least 99% of the Cumberland Valley in this State was originally timbered with a heavy forest, but very little of it was Chestnut, while on the adjoining mountain slopes of both the South and North Mountains, Chestnut is the prevailing species. Just as the Chestnut is essentially a tree of the slopes so the White Oak is essentially one of the bottom lands, and Table Mountain Pine of the mountain tops. The heading "Importance of the Species" was introduced simply to give general information concerning the forestal significance of the species and their adaptability for ornamental purposes. This heading is especially important when we realize that of the more than one hundred and twenty-five species of trees found in this State, 58 fewer than twenty-five are important for timber-producing purposes. Many inferior species which have little present or prospective value have been introduced into this publication, since it was thought just as important to know what not to plant as to know what to plant. Some species may not be valuable for the production of timber but they may have a value as shelter to other species or as soil pro- tectors and soil conservers. Many species which cannot be regarded as final members of a timber-producing forest may be of temporary value in helping to establish the more valuable permanent species. We should be cautious in eliminating the inferior species from our forest structure, because they may possess a value which is not evi- dent at the present time. It should be remembered that the species despised by myself may be prized by my neighbor, and that the species despised today by my neighbor and myself may be prized by both of us tomorrow. Only general statements are made with reference to the importance of the species. A fuller discussion of this heading may be found in any standard text on General Forestry or Silviculture. How TO IDENTIFY THE SPECIES AND USE THE KEYS: Since this publication is intended primarily for laymen and for students who are just beginning the study of trees, the omission of technical terms was thought advisable. We have many species of trees, some common, others uncommon, which the average layman may not know. He can learn them readily if their distinguishing characteristics are presented to him in ordinary language accom- panied by simple and exact drawings. This publication is designed so that the average layman with even a limited knowledge concern- ing trees can use it and identify the various species with little, if any, difficulty. The procedure or method of identification varies with the indi- vidual. One may take material from a tree and compare it with the drawings until he finds one with which it corresponds or to which it fits, and then feel satisfied that he has learned to know the tree. To check himself and to acquire additional information he may read over the descriptive material accompanying each plate. This method of comparison with plates, while the one commonly used by laymen who have little or no working knowledge concerning trees, is labor- ious and entirely unscientific. A better and yet simple method is the use of an analytic key for the identification of the species. Such keys according to their construction may be simple or complex, service- able or unserviceable to the average layman. In constructing the subjoined analytic key, an attempt was made to make it simple and yet exact, based upon permanent rather than transient, and constant 59 rather than variable characteristics. This publication will no doubt come into the hands of different classes of people, some of whom will recognize at a glance the genus to which a certain tree belongs, while others will not have the slightest idea as to what it is. An attempt has been made to satisfy both types of persons. The former can go at once to that portion of the publication where the genus under consideration is treated and by the use of the "Key to the Spec- ies" determine the exact species which they have at hand, while the latter should begin at the "Key to the Families" found on page 63, and use the key until the family to which it belongs is found, then go to the family and use the "Key to the Genera" and the "Key to the Species'7 until the species is determined. With a little practice one will find it easy to use such simple keys. Before attempting to use a key, it is necessary that good material be available. Parts of trees vary considerably, depending upon the environments in which they were developed. An abnormal environ- ment will produce abnormal organs, and if these should be the parts with which you are attempting to identify the species through the use of the keys, it is natural that it would be a difficult task. Struc- tural variations are commonly found in leaves, flowers, fruit, bark, as well as other plant organs. Upon the same tree or even the same branch one may find three or more distinct varieties of leaves. On account of this variation, which often makes identification difficult, abundant material should always be at hand, and especially that which is normal in appearance. The keys are based upon normal ma- terial and may not fit variable forms. Only by years of constant and careful study of trees will one be able to distinguish accurately be- tween normal and abnormal material ; but by carefully observing and constantly studying the trees one will unconsciously absorb many de- tails concerning them which can be appreciated but not described. This unconscious absorption of appreciable but indescribable detail in trees has a greater significance than we attribute to it at first. The writer, in conducting field work (Fig. 7) for five years in connec- tion with a course in Dendrology given at the Pennsylvania State Forest Academy, finds that the students learn to notice many differ- ences between species, which differences they cannot describe. The keys are subdivided into three classes, viz : "Key to the Fam- ilies," "Key to the Genera" and "Key to the Species." The "Key to the Families" is found on page 63, preceding the description of any of the species. The "Key to the Genera" is found under the descrip- tion of each family which contains more than one genus; and the "Key to the Species" is found under such genera which contain more than one species. The reason for subdividing the keys into three classes instead of combining all three into a general key to genera GO and species, was the fact that a combined key is often difficult to use on account of its great length, and tedious to operate for those who can recognize the family or genus at a glance but do not know the species. Besides, keys to the genera and keys to the species are more serviceable when placed close to the written description and its ac- companying plate than if they precede the descriptive material of all the species. The three classes of keys are constructed on the same plan; conse- quently, they can be used in the same manner. To use them it is necessary to make a choice for the most part between two alternatives stated in two paragraphs preceded by the same number. The choice leads to another number or to a family, a genus or a species followed by the page upon which a further description is found. The Sugar Maple may be taken as an example to show how to use the key. Un- der "Key to the Families," page 63, we start with 1. We have the choice between trees with "Leaves narrow, needle-like, awl-like, or scale-like, usually persistent except in the genus Larix" and trees with "Leaves broad, flat, rarely five times as long as wide, usually deciduous." We select the latter, which is followed by 2. Under 2 we have the choice between "Leaves opposite or whorled, i. e. 2 or 3 occur at a node" and "Leaves alternate, i. e. only one occurs at a node." We choose the former, which is followed by 3. Here we have the choice between "Leaves or at least most of them three at a node" and "Leaves always two at a node." We select the latter, which is followed by 4. Here we have the choice "Leaves simple" and "Leaves compound." We select the former, which is followed by 5. Here we have the choice between "Leaves palmately lobed" and "Leaves not lobed." We select the former, which is followed by Aceraceae, which is the family name for the Maples. This is followed by a number which indicates the page upon which a further descrip: tion of the family may be found. At this point it is advisable to check one's self. This can be done by carefully studying the descrip- tive matter of the family indicated in order to find out if the de- scription corresponds to the species under consideration. If the description does not correspond it is advisable to go back to the "Key to the Families" and attempt to find the mistake. If the de- scription does correspond it is reasonable to think that the "Key to the Families" was used correctly. If you feel certain that this is the correct family you should go to the "Key to the Genera," or to the "Key to the Species." No "Key to the Genera" is given under this family because it contains only one genus. Under the "Key to the Genera" and the "Key to the Species" the same method of procedure should be used that was used under the "Key to the Families." On account of the wide variation between the distinguishing characteris- Gl tics which are present in summer from those which are present in winter, it has sometimes been found necessary to make two keys to the species, one a summer key and the other a winter key. Two such keys are found under the Maple family. If the material at hand hap- pens to be a spray of leaves of the Sugar Maple, the summer key should be used, and if it happens to be a branchlet with buds, the winter key should be used. Since the family key which was used to this point was based pri- marily upon summer characteristics, the winter key will now be used in order to familiarize you with the slight variations which are found between the two keys. Under "Winter Key to the Species," page 191, we start with 1. Under 1 we have the choice between "Buds stalked with few exposed scales'7 and "Buds sessile or nearly so, with 6 or more exposed scales." We select the latter, which is followed by 4. Un- der 4 we have the choice between "Buds with 8-16 exposed scales, brown, acute, non-collateral; leaf-scars nearly encircle stem" and "Buds with 6-8 exposed scales, red or green, obtuse." We select the former which is followed by Sugar Maple (Acer saccharurn) page 194. On this page a full description of the species is found accompanied by a sketch on the opposite page of the principal characteristics. If the descriptive material and the sketches show that this is the species under consideration, one may feel satisfied that the key has been used properly. If the description does not correspond it is advisable to go back to the beginning of the key, follow the same pro- cedure indicated above but eliminating the mistake which must have been made. The same method of identification or procedure should be used for every other species. In a short time one will be familiar enough with the use of the key to identify the species and will do so with considerable accuracy. If you cannot identify the specimen at hand with the aid of the keys, description, and plates, there are still other means which you may use. It may be possible that an institution or a private person in your part of the State possesses an herbarium in which may be found a similar specimen properly labeled. If you can get access to such an herbarium and find that your specimen and the one in the herbarium are alike, and that the herbarium specimen was labeled by a reliable person, it is reasonable to assume that you have identi- fied your specimen correctly. It may also be possible that some one connected with some local educational institution will be able to as- sist you in identifying the material. All material sent to the Den- drological .Department of the Pennsylvania State Forest Academy, Mont Alto, Pa., will be identified free of charge. Persons sending material should always aim to send an abundance of it. If flow- ers, leaves, fruits, and bark are obtainable they should all be sent 62 The wider the range of material the easier and the more accurate the identification will be. Those who desire to collect and preserve material should proceed in the same manner as one would in making general botanical col- lections. The dried material may be secured on strong mounting paper. The writer has found the "Riker Specimen Mounts" very satisfactory for preserving and displaying the different parts of trees. Different sizes are obtainable, which allows one to select them in proportion to the size of the material to be preserved. GENERAL KEY TO THE FAMILIES. Page. 1. Leaves narrow, needle-like, awl like, or scale-like, usually persistent except in the genus Larix Pinaceae $7 1. Leaves broad, flat, rarely five times as long as wide, usually deciduous 2 2. Leaves opposite or whorled, i. e., two or three occur at a node, 8 2. Leaves alternate, i. e., only one occurs at a node 10 3. Leaves, or at least most of them, three at a node, Bignoniaceae 211 3. Leaves always two at a node, 4 4. Leaves simple, 5 4. Leaves compound 8 5. Leaves palmately lobed Aceraoeae 190 5. Leaves not lobed, 6 6. Leaves serrate, Viburnum in Caprifoliaceae 218 6. Leaves entire, 7 7. Leaves 3-6 inches long with curving parallel veins; bases of leaf stalks enlarged, encircling twigs Cornus in Cornaceae 204 7. Leaves 4-8 inches long without curving parallel veins; bases of leaf stalks do not en- circle twigs, Chionanthus in Oleaceae 217 8. Leaves palmately compound Sapindaceae 200 8. Leaves pinnately compound, 9 9. Leaflets usually 5-11; finely toothed or entire margined Fraxinna in Oleaceae 212 9. Leaflets usually 3, sometimes 5-lobed or coarsely serrate, ..Acer Negundo in Aceraceae 197 10. Leaves simple 11 10. Leaves compound, 40 11. Leaves persistent, 12 11. Leaves deciduous 14 12. Leaves not armed with spiny teeth 18 12. Leaves armed with spiny teeth, Ilex opaoa in Aquifoliaoeae 181 13. Small trees; leaves stout, white silky beneath, not taper pointed; flowers soli- tary, Magnolia virginiana in Magnoliaoeaa 156 13. Shrubs; leaves leathery, yellowish-green to scurfy beneath, often taper pointed; flowers in clusters Rhododendron and Kalmia in Ericaceae 207 14. Leaves with entire margins, 15 14. Leaves with toothed, lobed, or incised margins, 23 15. Leaves broadly heart-shaped; flowers reddish-purple, shaped like pea blossoms; fruit a pea-like pod, Cercis in Leguminosae 180 15. Leaves not broadly heart-shaped; flowers not shaped like pea blossoms; fruit not a pea-like pod, 16 16. Stout axillary spines present; fruit 3-5 inches in diameter, Maclura in Tlrticaceae 153 16. Stout axillary spines absent; fruit smaller 17 17. Leaves decidedly aromatic, often somewhat lobed; twigs spicy-aromatic, mucilagin- ous if chewed, Lauraceae 161 17. Leaves not aromatic or lobed; twigs not spicy-aromatic, nor mucilaginous, 18 18. Leaves 2-6 inches long; flowers small except pistillate of Diospyros, not soli- tary 19 18. Leaves more than 6 inches long; flowers large and solitary 22 18. Leaves bristle-tipped, linear-lanceolate to oblong; pith star-shaped; fruit an acorn.... Quercus imbrioaria and Q. phellos in Fagaceae 146 19. Leaves oval-ovate or obovate, not bristle-tipped; pith not star-shaped; fruit a drupe or a berry 20 64 Page. 20. Leaves thin, clustered at tip of twigs, with prominent curved parallel veins; small trees; twigs greenish streaked with white Cornus alternifolia in Cornaceae 205 20. Leaves thick, not clustered at the tip of twigs; veins not parallel; medium sized trees; twigs not greenish 21 21. Leaves 4-6 inches long; leaf petioles with one flbro-vascular bundle; fruit a globular berry 1-15 inches in diameter Ebenaceae 210 21. Leaves 2-5 inches long; leaf petioles with 3 flbro-vascular bundles; fruit a purple ovoid drupe f of an inch long Nyssa in Cornaceae 206 22. Stipules and stipule-scars encircle twigs; flowers greenish-white or yellowish; fruit cone-like; twigs often aromatic and bitter, Magnoliaceae 155 22. Stipules absent; flowers reddish-purple, ill-smelling; fruit banana-like, edible; twigs not aromatic or bitter Anonaceae 160 23. Leaf margins usually lobed or incised 24 23. Leaf margins usually toothed, 29 24. Leaves star-shaped Liquidambar in Hamamelidaceae 163 24. Leaves uot star-shaped , 25 25. Leaves silvery beneath Populus alba in Salicaceae 94 25. Leaves not silvery beneath, 26 26. Leaves rough on upper surface, with milky juice, Morus in TTrticaceae 154 26. Leaves not rough on upper surface, without milky juice, 27 27. Leaves decidedly aromatic, lobed or entire; twigs spicy-aromatic, mucilaginous, Lauraceae 161 27. Leaves not aromatic; twigs not spicy-aromatic nor mucilaginous 28 28. Leaves palmately veined; base of leaf petioles hollow; leaf lobes irregularly toothed. Platanaceae 175 28. Leaves pinnately veined; base of leaf petioles not hollow; leaf lobes rounded or bristle-pointed, intervening spaces deep or shallow, Most species in Fagaceae 123 29. Leaves with an oblique base, 30 29. Leaves uot with an oblique base, '. 32 30. Leaves ovate or ovate-oblong; rough on upper surface, TTlmus and Celtis in TTrticaceae 148 30. Leaves rounded, heart-shaped, or obovate; smooth on upper surface, 31 31. Loaves straight-veined with wavy margins; flowers in late autumn; fruit without bract. Hamamelis in Hamamelidaceae 162 31. Leaves not straight veined, deeply and sharply toothed; flowers appear in summer; fruit with bract Tiliaceae 202 32. Leaves dentate or coarsely toothed, 33 32. Leaves not dentate nor coarsely toothed 34 33. Leaves with laterally flattened petioles, Populus grandidentata in Salicaceae 97 33. Leaves not with laterally flattened petioles Few species in Fagaceae 124 34. Fruit dry, 35 34. Fruit fleshy 37 35. Leaves decidedly sour; flowers and fruit produced in racemes resembling the lily of the valley, .' Oxydendrum in Ericaceae 209 35. Leaves not sour; flowers and fruit nrt produced in racemes, 36 36. Fruit 1-seeded, nut or samara, subtended by bracts; seeds without tuft of hairs at apex; flowers monoecious; calyx present, Betulaceae 111 36. Fruit a small capsule inclosing numerous seeds; seeds with tuft of hairs at apex; flowers dioecious; calyx absent, Salicaceae 88 37. Thorns or spine-like spurs present, Prunus americana, Pyrus coronaria, and Crataegus sp. in Rosaoeae 164 37. Thorns or spine-like spurs not present 38 38. Fruit with a single stone Prunus in Rosaceae 165 38. Fruit several-seeded, 39 39. Leaves Heart-shaped or rounded at base, 3-4 inches long; flowers in loose racemes, Amelanchier in Rosaceae 174 39. Leaves wedge-shaped or rounded at the base, 4-5 inches long; flowers solitary or in one to few flowered axillary clusters Ilex monticola in Aquifoliaceae 189 65 40. 40. Leaves with entire margins ............................................................... 41 Leaves with toothed margins ........................... , ................................... 44 Page. 41. Leaves even-pinnate, .......................... Gleditsia and Gymnooladus in Leguminosae Leaves odd-pinnate ............................................................................ 42 177 42. 42. Leaflets small, elliptic; twigs thorny, ........................... Robinia in Leguminosae Leaflets large, ovate; twigs not thorny .................................................... 43 181 43. Leaflets 7-21, not toothed at base, without glands, Rhus Vernix and R. copallina in Anacardiaceae 183 43. Leaflets 11-41, sometimes with 2-4 blunt teeth at base which have glands on lower side at the point of each tooth Simarubaceae 187 44. Twigs and leaves prickly; leaves twice or thrice compound Araliaceae 199 44. Twigs and leaves not prickly; leaves once compound 45 45. 45. Large trees; stamina te flowers in aments; fruit a nut, .................. Juglandaceae Small trees; staminate flowers not in aments; fruit red and fleshy ....................... 46 100 46. Leaflets 13-15; sap not milky; branches heavy-tipped, Pyrus americana in Rosaceae 46. Leaflets 11-31; sap milky; branches heavy-tipped, Rhus typhina and R. glabra in Anacardiaceae 173 TABULATION OF GENERA AND SPECIES. Families, Genera, etc. Species. World. North America. Pennsylvania. Native. - Introduced. Gymnospermae. Fam. I. Pinaceae. Gen 1 Pinus 70 10 19 25 8 6 4 40 175 27 15 15 7 4 12 25 25 5 5 300 34 3 8 10 4 3 2 16 100 19 5 15 3 a i 15 10 1 3 55 6 1 2 1 1 1 ""z 4 (15)* 4 2 5(1) i (1) 1 1 1(1) 1 2 16 1 1 2 '"i 3 4 1 1 '"i i Gen 2 Larix, Gen. 3 Picea Gen 4 Abies Gen 5 Tsuga Gen 6 Chamaecyparis . Angiospermae. Fam. II. Salicaceae. Gen 9 Salix Fam. III. Juglandaceae. Fam. IV. Betulaceae. Fam. V. Fagaceae. Gen. 20. Quercus. . 5 Families, Genera, etc. Species. •d 1 North America. Pennsylvania. Native. Introduced. Fam. VI. Urticaceae. 15 60 4 25 1 8 2 3 3 7 40 30 700 90 2 7 11 7 7 120 275 70 15 20 30 40 7 100 6 1 160 40 2 7 100 2,819 6 1 3 8 1 8 1 1 1 3 10 23 60 43 1 3 3 7 1 16 22 13 7 8 15 15 5 10 6 1 a 16 1 2 20 661 2 f .... 1 3 1 1 1 1 1 1 2 (4) 1 (3) 2 (14) 4 (10) 1 1 1 2 3 (3) 2 (3) 6 2 2 1 (3) 2(6) |« 1 j<« 2(8) 113 (76)* 1 .... 1 1 ""s 1 2 1 2 29 Gen 22 Celtis • • • • • Gen 24 Morus Fam. VII. Magnoliaceae. Fam. VIII. Anonaceae. Fam. IX. Lanraceae. Gen 28 Sassafras Fam. X. Hamamelidaceae. Fam. XI. Platanaceae. Fam. XII. Rosaceae. Gen 32 Pyrus Gen 83 Amelanchier, Fam. XIII. Leguminosae. Gen 38 Gleditsia Gen 39 Robinia Fam. XIV. Simarubaceae. Gen 40 Ailaiitbus Fam. XV. Anacardiaceae. Gen 41 Rbus Fam. XVI. Aquifoliaceae. Gen. 42. Ilex, Fam. XVII. Aceraceae. Gen 43 Acer, Fam. XVIII. Sapindaceae. Fam. XIX. Tiliaceae. Gen 45 TiUa, Fam. XX. Araliaceae. Gen 46 Aralia Fam. XXI. Cornaceae. Gen. 48. Nyssa, Fam. XXII. Ericaceae. Gen. 49. Rhododendron, . . Gen. 50. Kalmia, Gen. 51. CKydendrum, Fam. XXIII. Ebenaceae. Gen. 52. Diospyros, Fam. XXIV. Oleaceae. Gen. 53. Fraxinus Gen. 54. Chionanthus, Fam. XXV. Bipnoniaceae. Gen. 55. Catalpa, Fam. XXVI. Caprlfollaceae. Gen. 56. Viburnum Total •The numbers giveu in parenthesis refer to species native to Peunsylvania but not described and rarely mentioned in this publication. 67 THE PINE FAMILY— PINACEAE. There is general agreement that the Pine and Yew families com- prise the two divergent branches of the conifers which differ from each other in morphological characters and geographical distribu- tion. The conifers comprise 34 genera and about 300 species, of which number 8 genera with 71 species belong to the Yew family (Taxaceae) and 26 genera with 226 species to the Pine family (Pinaceae). The representatives of these two families are found mainly in temperate regions, both northern where the genus Pinus predominates, and southern where the genus Podocarpus predomi- nates. The geographical distribution of these two families is pecu- liar since the genera of the northern temperate region are not found in the southern and those of the southern are not found in the northern, excepting the two genera (Heyderia and Podocarpus) which cross the tropics. Geological records together with the sim- plicity of floral structure show us that the members of this family are amongst the oldest living representatives of the ancient arbores- cent type of vegetation. Morphological evidence seems to point to the belief that the Yew family contains representatives of the most primitive form of conifers and that the genus Pinus in the Pine family contains the most highly specialized forms. The sole representative in Pennsylvania of the family Taxaceae is the Ameri- can Yew or Ground Hemlock (Taxus canadensis, Marsh.) It is a small evergreen shrub seldom exceeding 5 feet in height. The Pine family is of especial economic value on account of the many commercial products which are obtained from it and the wide range of silvicultural characteristics which its members possess. The annual wood production of the members of this family in the United States far surpasses that of the members of any other fam- ily. The wood differs markedly from that of the broad-leaved trees in its greater uniformity, smaller porosity, and less conspicuous medullary rays. Some members of this family yield large quantities of resin, tar, turpentine, and pitch. The fruit of some species is often of considerable importance as food, and the bark of many species is used in the process of tanning. The members of the Pine family have awl-shaped, scale-shaped, or needle-shaped entire leaves, which are usually persistent. The American Larch is the only coniferous species native to Pennsylva- 68 nia which is without foliage in winter. The subjoined key gives the characteristics of the genera commonly found in Pennsylvania: KEY TO THE GENERA. Page. 1. Fruit a dry cone with winged seeds 2 1. Fruit a fleshy, round, dark-colored berry with bony seeds, Juniperus 87 2. Leaves linear to needle-shaped, not closely overlapping; cone-scales numerous; buds scaly 3 2. Leaves scale-like, closely overlapping; cone-scales few; buds not scaly ..7 3. Leaves in bundles of two or more except on young seedlings and on terminal twigs of Larix, 4 3. Leaves solitary • 5 4. Leaves persistent, 2-5 in each bundle, Pinus 68 4. Leaves deciduous, more than 5 in each cluster, Larix 77 5. Leaves flattened, whitish on lower surface, 6 5. Leaves 4-angled, needle shaped Picea 78 6. Leaves with leaf-like stalks, about 2/5 of an inch long; twigs rough; cones small with persistent scales, Tsuga 83 6. Leaves without leaf-stalks, usually 4/5 of an inch or more in length; twigs smooth; cones large with deciduous scales, Abies 84 7. Leaves less than J of an inch long; twigs rather slender, not prominently flattened; cones globular with shield-shaped scales which do not overlap Chamaecyparis 85 7 Leaves J of an inch or more in length; twigs rather prominently flattened; cones elongated with 8-12 overlapping scales Thuja 86 THE PINES— PINUS (Tourn.) L. This genus comprises more species than any other belonging to the Pine family. About 70 species are known in the world, 34 of which are found in North America and 6 in Pennsylvania. Of the 34 species in North America, 13 are found in the eastern part and 21 in the western part. Besides the native Pines a number of exotic species have been planted extensively for ornamental, and locally for forestry purposes. The commonest exotic species are Scotch Pine (Pinus sylvestris, L.) and Austrian Pine (Pinus Laricio var. austriaca, Endl.). The Pines are adapted to a wide range of climate and soil. Cer- tain species may be found bordering streams and lakes or close to the ocean front while others are confined to mountain tops where they ascend to the timber line. This adaptability makes some of the species of considerable economic value even though they may produce no wood of commercial importance. They can be used for afforesting mountain slopes where protection forests are to be formed and maintained, and to reclaim sand barrens. The Pines are generally trees, rarely shrubs, and of considerable commercial importance on account of the excellent qaality and large quantity of major and minor forest products which they yield. Sev- eral species of Pine have always been foremost in the estimation of 69 lumbermen and the public since the American Forests began to be exploited. Until recently more pine lumber has been produced an- nually in the United States than all other kinds of lumber com- bined. The lumber-producing pine trees have played a very impor- tant role in our economic and industrial development. The Pines are distinguished commercially into two classes, Soft Pines and Hard Pines. In the United States there are 12 species of Soft Pine, and 22 species of Hard Pine. The White Pine is the sole eastern representative of the Soft Pines, while the Hard Pines have 12 repre- sentatives in the eastern and southern United States. The Pines have three lands of leaves: seed, primary, and secondary leaves. The primary leaves soon disappear and are seldom seen ex- cept on seedlings. The secondary leaves occur singly or in clusters of 2 to 5 and often have a persistent or deciduous sheath surrounding them at the base. They are semi-circular or triangular in cross- section, depending upon the number which occur in a cluster. The flowers usually appear in spring. The staminate are borne at the base of the season's growth in clusters and produce enormous quanti- ties of sulphur-like pollen. The pistillate occur near the terminal part of the new shoot or laterally along it, solitary or in whorls of 2-5 or more. Prior to pollination they normally stand erect but after this process has been completed they begin to droop. The wind is the chief agent of pollination. Fertilization takes place about 13 months after pollination. The result of these processes is usually a cone which matures at the end of the second or sometimes the third season. The cones are composed of numerous scales at the base of which the seeds are produced in pairs. KEY TO THE SPECIES. Page. 1. Leaves 5 in a sheath, slender, with 1 flbro-vascular bundle, P. Strobus 70 1. Leaves fewer than 5 in a sheath, usually stout, with 2 flbro-vascular bundles, 2 2. Leaves 3 in a sheath, P. rigida 71 2. Leaves 2 in a sheath, 3 3. Leaves 5-6 inches long; cones subterminal, scales unarmed, P. n&sinosa 72 3. Leaves less than 5 inches long; cones lateral, scales armed with spines or prickles, .4 4. Cones 2J-3J inches long, armed with stout spines; leaves very sharp-pointed and stiff, P. pungens 73 4. Cones 3 inches or less in length, armed with prickles; leaves slender to slightly stiff, .5 5. Leaves slender, straight, occasionally 3 in a sheath, 4 inches long or less, P. echinata 74 5. Leaves stout, twisted, 1J-3J inches long 6 6. Twigs smooth, greenish-purple to grayish-brown; cones at right angles to branch P. virginiana 75 6. Twigs rough, dull grayish-yellow; cones pointing backward; bark of tipper third of trunk reddish; European species, P. aylvestris 76 70 WHITE PINE. Pinus Strobus, Linnaeus. FORM — At present seldom exceeding 3 ft. in diameter and 125 ft. in height, usually 50-90 ft. high and 15 to 3 ft. in diameter. When grown in dense stands (Figs. 1 and 10) the trees are tall, straight, free from lateral branches for a considerable distance from the ground, have little stem-taper and shallow crowns. When grown in the open (Fig. 34, specimen on left), it has much stem-taper is relatively low, often forked, covered with persistent lateral branches almost to the ground which make it attractive ornamentally but of low commercial value. BARK — On young branches, thin, smooth, greenish -brown; later scaly and darker. On old trees thick, dark gray, and divided by long and shallow fissures into broad longitudinal ridges (See Fig. 44.) - TWIGS — Slender, flexible, at first hairy, slightly roughened by raised leaf-scars. New growth at first light green and erect. During first winter light brown in color, less erect in position, very resinous if punctured. BUDS — In terminal cluster, ovate-oblong, sharp-pointed, with numerous brown, long-pointed and overlapping scales. Apical bud I-* of an inch long. Lateral buds about i of an inch long. LEAVES — Light green when young and bluish-green, soft, flexible, 2|-5 inches long when mature; persist usually until end of second season, occur in clusters of five, are -triangular in cross-section, contain one fibro-vascular bundle, have finely serrate edges and are surrounded at the base by a deciduous sheath. FLOWERS — Appear about May. Staminate flowers clustered at base of new growth of season, yellow, oval, about i of an inch long. Pistillate flowers solitary or in small groups, lateral along new growth, pinkish-purple, cylindrical, about 1 of an inch long. FRUIT — A cone maturing in two seasons, 5-10 inches long, drooping, stalked, slightly curved, and covered with thin unarmed scales without thickened apex. Seeds are winged, J of an inch long, dark brown in color on both sides and mottled with black spots. WOOD — Non-porous; resinous, soft, straight-grained, easily worked, light brown except sapwood which may be almost white. Weighs 24.04 Ibs. per cubic foot. Formerly used for a wider range of purposes than any other native species and adapted for practically all uses except where strength, hardness, flexibility and durability in contact with soil are required. DISTINGUISHING CHARACTERISTICS— The White Pine is the only species of Pine native to eastern North America which has soft, flexible, bluish-green needles in clusters of five. The lateral branches, usually 3-7 in a whorl, are arranged in distinct horizontal layers. The cones are 5-10 inches long, long-stalked, and their cone-scales are thin, flat, and unarmed. RANGE — Newfoundland to Manitoba on the north, south through northern states to Penn- sylvania and along the Allegheny Mountains to Georgia, and southwest to Iowa. DISTRIBUTION IN PENNSYLVANIA— Common in the mountainous portion of the State. Originally formed heavy stands especially in the central and northern parts of the State. Some- times pure but usually mixed with other species. Found sparingly in the southwestern and south- eastern parts where it is usually limited to cool ravines and north slopes. Rarely found at present in valleys like the Cumberland, Lancaster, Chester, lower Lehigh and lower Delaware. HABITAT — Prefers a fertile, moist, well-drained soil, but will grow well on dry sandy, soils and gravelly slopes. Common on banks of streams, river fiats, in hollows and ravines, but rarely found in swamps. Any habitat in its natural range will be favorable to its develop- ment except swamps and ridges exposed to severe winds. IMPORTANCE OF THE SPECIES— White Pine is one of the most important timber trees of the United States. It is indigenous to America but was introduced into England by Lord Wey- moutb in 1705 and shortly afterwards into Germany where it is no longer regarded an exotic species but a naturalized member of the German forest. This species can be recommended for forestry purposes, because it may be regenerated successfully both naturally and artificially as shown by the numerous and extended German experiments. It adapts itself to a great variety of soil conditions, is a rapid grower, is very attractive ornamentally, and will thrive in pure or mixed stands; but the latter are best on account of less danger from disease, better natural pruning, and earlier financial returns from thinnings. PLATE XII. WHITE PINE. 1. Branch with needles and terminal cluster of buds, x i. 2. A cluster of five needles, x J. 3. Tip of needle with sharply serrate margin, enlarged. 4. Branch with staminate flowers, x J. 5. Branch with (a) pistillate flowers on new growth (b) one-year old cone on last season's growth, x |. 6. Branch with an open and a closed cone, x j. 7. Lower side of a cone scale, x J. 8. Upper side of a cone scale with two winged seeds, x J. 9. A winged seed, x J. 10. A seed, natural size. 11. Section of seed with embryo, natural size. 12. A seedling, x J. PLATE XIII. PITCH PINE. 1. Branch with needles and terminal cluster of buds, x J. 2. A cluster of three needles, x J. 3. Tip of a needle with serrate margin, enlarged. 4. Branch with needles and a closed cone, x i. 5. An open cone, x J. 6. Lower side of a cone scale, x J. 7. Upper side of a cone scale with two winged seeds, x }. 8. A winged seed, natural size. 9. A seed, natural size. 71 PITCH PINE. Pinus rigida, Miller. FORM — Usually attains a height of 40-50 ft. and a diameter of 1-2 ft. and seldom exceeds 70- 80 ft. in height and 3i ft. in diameter. Trunk rather tapering except in occasional pure and closed stands. Opeu grown trees have an irregular wide pyramidal crown. Branches numerous, irregular, gnarled, often drooping, and covered by small plate-like scales and numerous persistent cones. Crown is often so irregular and scraggy in appearance that it becomes picturesque. BARK — On young branches green and smooth soon becoming yellowish, later grayish-brown and roughened by persistent bases of the bud-scales. On young trunks roughened with red- di&h -brown scales, with age becoming rougher through deep furrows and flat ridges which separate into thin reddish-brown scales. The scales sometimes appear black, whence the name Nigger Pine. See Fig. 46. TWIGS— Stout, brittle, smooth, brown and very rough on account of persistent elevated and decurrent bases upon which the leaf-clusters rested. BUDS — Ovate, sharp-pointed, often resinous, 1-1 of an inch long, covered with imbricated, loose, brown, and shining scales. LEAVES — In sheathed clusters of 3, stout, rigid, dull-pointed, closely and sharply toothed, at first light green, later yellowish-green, 2J-5 inches long, with stomata on all sides, and contain 2 fibro-vascular bundles and 3-7 resin-ducts. FLOWERS — Appear in April or May. Staminate flowers clustered at base of new growth of season, are cylindrical, yellow, J of an inch long, and produce an enormous amount of pollen. Pistillate flowers solitary or clustered, lateral on new growth, at first green, later tinged with red. FRUIT — A cone maturing in 2 seasons, l$-3i inches long, sessile or short-stalked, ovate, occurs solitary or whorled, often stands at right angles to the branch, and persists for 10 or more years. Cone scales thickened at apex, armed with short rigid recurved prickles. Seeds winged, dull or glossy black, sometimes mottled with gray or red dots. WOOD — Non-porous: resinous, light, brittle, coarse-grained, rather durable, brownish-red with abundant lighter sapwood. Weighs 32.10 Ibs. per cubic foot. Used for railroad ties, charcoal, mine props, fuel, sometimes for construction timber and lumber. DISTINGUISHING CHARACTERISTICS— The Pitch Pine, also known as Jack Pine and Nigger Pine, is the only native Pine of Pennsylvania with leaves in sheathed clusters of 3. The Yellow Pine may occasionally have the needles in clusters of 3, but usually 2. Pitch Pine has a very irregular and scraggy appearance due to the dead and gnarled branches which are often covered with clusters of persistent cones. The bark is thick and irregularly fissured with In- tervening flat ridges which separate into thin reddish-brown sometimes black scales. Trunks are often fire scarred. Such trunks are frequently covered with dense mats or clusters of leaves and short branches. RANGE — New Brunswick to Lako Ontario on the north, south to Virginia and along moun- tains to Georgia, and west to western New York, Kentucky and Tennessee. DISTRIBUTION IN PENNSYLVANIA— Found in practically all parts of the State, but rare and local in the southeastern and southwestern parts. Occurs in excellent pure stands at the base of the South Mountains in Franklin county, and in Pike county. Sparse in the rich agricultural sections of the State. In many regions it occurs only as a scattered tree mixed with hardwoods. HABITAT — Common on dry burned-over areas, sterile plains, gravelly slopes, rocky cliffs, and sometimes found in swamps. In the glaciated area it is common on rocky glacial soil. IMPORTANCE OF THE SPECIES— From a commercial point of view this species is not so important as the White Pine or the Red Pine, but It is gradully growing in importance since new uses are found for the wood and prices of other woods are rising. Silviculturally it is valuable on account of its adapatability to poor soil and its fire resisting qualities. These qualities recommend it for reforesting neglected or fire endangered lands on mountain slopes as well as low sandy areas. It may not be the species ultimately desired upon the area, but may act as a shelter during the establishment of a stand of a more valuable species. 72 RED PINE. Pinus resinosa, Aiton. FORM — Usually from 50-75 ft. in height with a diameter of 2-3 ft. but reaching a maximum height of 140 ft. with a diameter of 4J ft. In closed stands trunk is straight, tall, slightly- tapering, and free from lateral branches for a considerable distance from the base while in, open stands the lateral branches extend nearly to the base and the trunk is often branched and strongly-tapered. Crown usually broad, irregular, pyramidal, with dark green foliage tufted at the ends of the branches. See Fig. 42. BARK — Reddish-brown, f-li inches thick, divided by shallow furrows into broad flat ridges which peel off in thin scales. See Fig. 45. TWIGS — Stout, slightly roughened by persistent bases of bud-scales; at first yellowish-brown, later reddish-brown. BUDS — Ovoid, pointed, 1-2 of an inch long. Bud-scales brown, thin, loose, and fringed on the margin. LEAVES — In sheathed clusters of 2, 4-6 inches long, dark green, rather slender and flexible, sharp, persisting for 3-5 years. FLOWERS — Appear in May. Staminate flowers about \ of an inch long, occur In dense clusters at base of growth of season, have dark purple anthers. Pistillate flowers subterminal, 2 to 3 in a whorl, short-stalked, scarlet. FRUIT — A cone about 2 inches long, nearly sessile, light brown, ovate-conical when closed and somewhat spherical when open, persisting until the following year. Cone-scales chestnut- brown with ends slightly thickened and transversely ridged but not armed with spines or prickles. WOOD — Nomporous; resinous, bard, pale red, with thin light sapwood, and very conspicuous medullary rays. Weighs 30.25 Ibs. per cubic foot. Green wood is very heavy and will sink. Used for heavy construction, piles, masts, in general for nearly all other purposes for which White Pine is used. DISTINGUISHING CHARACTERISTICS— The Red Pine, also known as Norway Pine, is es- sentially a northern tree and is the only native Pine of Pennsylvania with needles 4-6 inches long, sheathed in clusters of 2. Its cones are about 2 inches long, subterminal, and bear scales which are not armed with spines or prickles. The needles are torne in tufts at the ends of branches. RANGE — Distinctly a northern tree occurring from Nova Scotia and Quebec on the north to Pennsylvania on the south, and west to Minnesota. DISTRIBUTION IN PENNSYLVANIA— Found only in the northern part of the State. Its southern limit in the central part of the State is about at Williamsport. In the eastern and western parts it does not come so far south as in the central part. HABITAT — Usually found on dry gravelly ridges, mountain-tops, and dry sandy plains. Rare on flat lands with wet clay soil. IMPORTANCE OF THE SPECIES— The Red Pine is a valuable timber tree usually mixed with other species of trees but occasionally found in dense pure stands in Minnesota. This tree is remarkably well adapted to natural seed regeneration since it produces a great quantity of light, large-winged seeds which are readily disseminated by the wind and does not shed an its seeds at the same time. It readily adapts itself to variable conditions, Is attractive ornamentally, and should be regenerated naturally where seed trees are at hand and arti- ficially upon such areas where other more valuable trees will not grow. PLATE XIV. RED PINE. 1. Branch with needles and terminal cluster of buds x 4 2. A cluster of two needles, x J. 3. Branch with needles and cones, x J. 4. Lower side of an unarmed cone scale, natural size. 5. Upper side of a cone scale with t\vo wingi-d seeds, natural 6. A winged seed, natural size. 7. A seed, natural size. 8. A seedling, x J. size PLATE XV. TABLE MOUNTAIN PINE. 1. Branch with needles and terminal cluster of buds, x i. 2. A cluster of two stiff, twisted and sharp-pointed needles, x 4. 3. New growth with two pistillate flowers, x J. 4. Branch with needles and a whorl of three cones, x J. 5. Lower view of a cone scale with a spine, x J. 6. Lpper view of a cone scale with two winded seeds, x i 7 A winged seed, s J. 8. A seed, natural size. 73 TABLE MOUNTAIN PINE. Pinus pungens, Lambert. FORM — Usually attains a height of 30-40 ft. with a diameter of 1-2 ft., but when crowded In a closed forest stand it may attain a height of 60 ft. with a diameter of 2J-3 ft. Crown in closed stands shallow, irregular, narrow, and round-topped. In the open the trunk is short, bearing short lateral branches, the upper ones ascending and the lower ones drooping. Often the tree is covered with branches to the base of the trunk so that the lower branches lie prostrate on the ground. See Fig. 43. BARK — Dark reddish-brown, J-| of an inch thick, roughened by shallow fissures into irregular plates which peel off in thin films. TWIGS — Stout, rather brittle, at first smooth and light orange to purplish, later rather rough and dark brown. BUDS — Resinous, narrowly elliptical, blunt-pointed, covered with overlapping brown scales. Terminal buds about J-2 of an inch long, the lateral shorter. LEAVES — In clusters of 2 surrounded by a persistent sheath, 2-4 inches long, light bluish- green, stout, very stiff, more or less twisted, very sharp-pointed, tufted at the end of the branches, persisting for 2-3 years. FLOWERS— Appear in April or May. Staminate flowers occur in long, loose clusters at the base of the growth of the season; have yellow anthers. Pistillate flowers appear laterally along new growth in whorls of 2-5 or 7, and are very short and stout-stalked. FRUIT — A cone 3-4 inches long, sessile, oblique at the base, in whorls of 2-5 or 7 or even more, light brown, short ovoid, persisting for 15 or more years but shedding seeds soon after maturity. Cone-scales, especially those near base, much thickened and provided with a strong curved spine. A branch 7 years old, li inches thick at the thickest end and 31 ft. long bore 36 cones. Trees 5 years old and 2-3 ft. tall can be found which bear developing cones. WOOD — Non-porous; resinous, brittle, coai-se-grained, pale reddish-brown with light sapwodd. Weigh 30.75 Ibs. per cubic foot. Used primarily for fuel and charcoal, and occasionally sawed into lumber. DISTINGUISHING CHARACTERISTICS— The Table Mountain Pine, also known as Poverty Pine, can readily be distinguished by its coarse and massive cones armed with very stout curved spines. The cones appear usually in whorls of 3, 5, 7 or more and persist for many years. The stout, twisted, and very sharp-pointed needles are also characteristic. The growth is rather slow and the terminal shoots are stout, stiff, and rough. RANGE — From Pennsylvania and New Jersey along the mountains to North Carolina and north- ern Georgia. DISTRIBUTION IN PENNSYLVANIA— Sparse to abundant upon the mountains In- the south- central part of the State and extends northeast on the mountains to Schuylkill county. It is primarily a southern species which occurs in pure stands on the mountains in Franklin county. Common on some mountains in Fulton, Blair, Huntingdon, Mifflin, Perry, and Union coun- ties. Small outposts of it are also reported from Lancaster and York counties. HABITAT — Commonly found on dry, rocky, and gravelly slopes. Occasionally found at the base of the mountains on somewhat moist clayey soil. IMPORTANCE OF THE SPECIES — The lumber obtained from this tree is of little commercial importance on account of its small size and the numerous knots which it contains. It is a very aggressive species and is adapted for the regeneration of worn-out fields as well as to pro- tect rocky slopes and prominences from erosion. It occasionally reaches a size which will yield lumber. Trees 20 inches in diameter and with a clear length of 25 feet are not uncommon locally in the southern part of the State. YELLOW PINE. Pinus echinata, Miller. FORM — Attains height of 80-100 ft., occasionally 120 ft. and diameter of 2-3 ft., occasionally * ft. Crown shallow, wide, pyramidal or rounded. Trunk clean, tall, and slightly tapering. Lateral branches relatively light, very brittle, intolerant of shade, and consequently drop off very early producing the clean, tall, and stately trunk. See Figs. 11 and 34. BARK — On young branches at first pale green and smooth, later reddish-brown and scaly. On old trees dark brown tinged with cinnamon-red, often i-1 inch thick, broken by distinct fis- sures into irregular, often rectangular plates which peel off very readily into numerous thin filmy scales. See Fig. 47. TWIGS — Stout, brittle, slightly rough, at first often covered with glaucous bloom, later be- coming reddish-brown. BUDS — Ovoid, dull-pointed, covered with sharp-pointed dark brown scales. LEAVES — Usually in clusters of 2 sometimes 3 or even 4, slender, flexible, faintly toothed, abruptly pointed, dark bluish-green, 3-4 inches long, surrounded by persistent sheath, and per- sisting for 2-5 years. FLOWERS — Appear in April or May. Staminate flowers clustered at base of new growth of season, nearly sessile, pale purple. Pistillate flowers rarely solitary, but usually 2-4 in a whorl Just below end of new growth, borne on stout erect stems, and pale rose colored. FRUIT — A cone maturing In 2 seasons. One year old cones short-stalked, oval, about 1/6-i of an inch long. Mature cones short-stalked or sessile, conic when closed and ovoid when open, 11-2 inches long, often persisting for 2 or more years. Cone-scales have slightly enlarged ends terminated by weak or deciduous prickles. Seeds small, triangular, 3/16 of an inch long, i of an inch wide, pale brown mottled with black spots. WOOD — Non-porous; resinous, hard, strong, with distinct spring and summer wood, yellow- ish or dark brown. Weighs 38.04 Ibs. per cubic foot. It furnishes the most desirable of the yellow pine lumber of commerce and is largely manufactured into lumber used for general construction and carpentry. DISTINGUISHING CHARACTERISTICS— The Yellow Pine, also known as Short-leaf Pine, is rarely found in the northern part of Pennsylvania which will prevent confusing It with the Red Pine native only to the northern part of the State. It can be distinguished from the other species of Pine found growing with it in this State by its rather slender flexible leaves in sheathed clusters of 2, sometimes 3 or 4, its conic cones with scales terminated by weak or deciduous prickles, ,its brittle branchlets, and its clean, stately, slightly-tapering trunk, the bark of which is marked off by deep furrows into irregular or rectangular plates which peel off very readily into numerous thin film-like scales. The needles are shorter and slenderer than those of the Pitch Pine. RANGE — Southeastern New York and northern Pennsylvania to Florida, westward to Illinois, Kansas and southeastern Texas. DISTRIBUTION IN PENNSYLVANIA— This is essentially a southern species but extends into Pennsylvania. It is usually mixed with hardwoods. Large specimens of it are found in the Benjamin George tract (Fig. 11) near Mont Alto, Franklin county. It is also reported on the Cook tract in Jefferson and Forest counties, and in Fulton, Lancaster, Perry, Lycoming, and Union counties. HABITAT — Common on poor, sandy, or clayey soil. It is a tree of the plains and foothills. Reaches its optimum development on the uplands and undulating plains west of the Mississippi. In the east it is usually mixed with hardwoods. IMPORTANCE OF THE SPECIES — Next to the Long-leaf Pine this species is the most im- portant of the Southern Pines. It is destined to play a very important role in future forest management in the regions where the conditions of growth are favorable, on account of its economic and commercial value. This species, on account of the ease with which it regenerates naturally, requires little assistance from the hands of the forester. It can be planted upon favorable situations anywhere in Pennsylvania. PLATE XVI. YELLOW PINE. 1. Branch with needles and terminal cluster of buds, x J. 2. A cluster of two needles, x J. 3. Tip of a needle with flnel> serrate margin, enlarged. 4. Branch with needles and an open cone, x \. 5. Upper side of a cone scale with two winged seeds, x 4 6. Lower side of a cone scale, x J. 7. A winged seed, natural size. 8. A seed, , slightly enlarged. PLATE XVII. JERSEY OR SCRUB PINE. 1. Branch with needles and terminal cluster of buds, x |. 2. A cluster of two needles, x 4 3. Tip of a needle with finely serrate margin, enlarged. 4. Branch with needle and closed cones, x |. I 5. Lower side of a cone scale, x i. 6. Upper side of a cone scale with two winged seeds, x S. 7. A winged seed, natural size. 8. A seed, natural size. 75 JERSEY OR SCRUB PINE. Pinus virginiana, Miller. FORM — Usually attains a height of 30-40 ft. with a diameter of 18 inches, but reaches larger dimensions, especially in Indiana. Trunk usually short since the long horizontal or pendulous branches cover It almost to the base. Young trees have a pyramidal form while older trees develop a rather flat-topped conic form. BARK — On the trunk i-i of an inch thick, dark reddish-brown, shallowly fissured into small flat plates separating into thin film-like scales. Smoother than that of our other native Pines. See Fig. 48. TWIGS — Slender, tough, flexible, rather smooth, at first greenish-purple and covered with a glaucous bloom, later light grayish-brown. BUDS — Ovate, sharp-pointed, 1-J of an inch long, covered with overlapping, sharp-pointed, brown scales. LEAVES — In clusters of 2 with persistent sheath, 1J-3 inches long, twisted, bright green, rather stout, fragrant, sharply thick-pointed, finely toothed, divergent above the sheath, and closely dispersed on twigs. FLOWERS — Appear in April or May. Staminate flowers crowded at base of growth of season, J of an inch long, oblong, with yellowish-brown anthers. Pistillate flowers appear near the middle of the season's growth and are long-stalked, sub-globose, solitary, or few in a whorl. FRUIT — A cone, 2-3 inches long, usually sessile, sometimes slightly curved, conical when closed and ovoid when open, seldom persisting for more than 3 or 4 years. Cone-scales thin, nearly flat, thickened at apex, and terminated with a prickle. Seeds rounded, i of an inch long, J of an inch wide, and pale brown. WOOD — Non-porous; slightly resinous, light, soft, brittle, pale orange, with very light sap- wood. Weighs 33.09 Ibs. per cubic foot. Used for fuel, and to some extent for railroad ties and lumber. DISTINGUISHING CHARACTERISTICS— The Jersey or Scrub Pine can be distinguished by its short, twisted, and divergent needles distributed in pairs along the smooth, purple, slender, often curved, and tough branchlets. The cones are small, with thin rather flat scales and provided with slender prickles. The divergent and twisted needles closely dispersed on the twigs give rather a disheveled appearance to them, and permits one to distinguish this tree at a distance since the light of the background is diffused through it so evenly. The bark is smoother than in the other native species of Pine, and upon older specimens decidedly reddish in color. RANGE — Southeastern New York and Pennsylvania, south to Georgia and Alabama, west to Indiana and Kentucky. DISTRIBUTION IN PENNSYLVANIA— Found locally throughout the southern part of the State. It is primarily a southern species and extends as far north as Allegheny county in the western part, Clinton and Lycoming counties in the central part, and Northampton county in the eastern part. In Franklin county it is usually found at the base of the mountains, seldom ascending the mountains or extending into the valley. HABITAT — Common on light sandy or poor rocky soil. It is common on the sand barrens of New Jersey, and on exhausted farm land and cut-over areas. IMPORTANCE OF THE SPECIES— It is not of much importance as a timber tree on ac- count of its small size. While it is of little commercial importance still it is of considerable economic value as a reforester of worn-out and neglected lands. For ornamental purposes it has been used very little, other species being preferred. 76 SCOTCH PINE. Pinus sylvestris, Linnaeus. FORM— Usually 70 ft. high with a diameter of 1J-3 ft. but may attain a height of 120 ft. with a diameter of 3-5 ft. In the United States it is usually planted in the open and consequently it has a short, clean, often branched trunk bearing numerous, more or less drooping lateral branches. Trees in closed stands produce straight and clean trunks with little taper and a short compact crown. At a distance it resembles the Pitch Pine. BARK — On the trunk scaly and peels off in flakes from the ridges which are separated by long shallow fissures. Lower part of the trunk is rough while the upper is rather smooth and distinctly reddish in color. Outside bark on the lower trunk is grayish-brown while the inner is reddish-brown. TWIGS — Fairly stout, brittle, dark yellowish-gray, smooth, not glossy. BUDS — Ovate, blunt-pointed, brown, often somewhat resinous. LEAVES — In sheathed clusters of 2, 15-35 inches long, bluish-green, or dark green, stout, twisted, semi-circular in cross-section and containing 2 fibre-vascular bundles. FLOWERS — Appear in April or May. Staminate flowers clustered on the lower half of this season's growth, ovate, scarcely 2/5 of an inch long. Pistillate flowers appear singly or in 2s Just below the terminal buds of this season's growth, are ovoid and short-stalked. FRUIT— A cone 1}-2J inches long, short-stalked, conic-oblong, solitary or in 2s usually pointing backward and grayish or reddish in color. WOOD — Non-porous; resinous, light, reddish-brown with thick light yellowish or reddish sap- wood. Used for general construction, lumber, railroad ties, hop-poles, grape vine poles and fuel. DISTINGUISHING CHARACTERISTICS— The Scotch Pine, a native of Europe, may be dis- tinguished from the other Pines of Pennsylvania by the reddish appearance of the upper part of the trunk and adjoining branches, the bluish-green leaves l$-3$ inches long, and the backward- pointing cones. It has rougher twigs than the Jersey or Scrub Pine, shorter needles than the Red Pine, stouter needles than the Yellow Pine, and blunter-pointed needles than the Table Mountain Pine. RANGE — Not native to America. Abroad it extends over the greater part of Europe and part of western Asia. In the United States it can be planted over a large area in the northeastern states, the lake states, and some of the prairie states. Planted for ornamental purposes in many parts of this State and by the Pennsylvania Department of Forestry in numerous plantations. HABITAT — This species is indifferent to soil requirements, water, heat of summer, and cold of winter. It will grow on all classes of soil, even dry, sterile sand. The rate of growth depends more on the physical structure than the chemical composition of the soil. It pre- fers deep well drained sandy loam. It is very intolerant of shade. IMPORTANCE OF THE SPECIES— The Scotch Pine is a very important tree in its native and adopted European home. It plays a prominent role in the forest structure of parts of Ger- many, such as the sandy plains along the Rhine and the large sandy areas of northern and eastern Prussia. Excellent forests of this species can be seen in Germany, but it is not necessary to introduce it into the United States extensively for forestry purposes since we have superior native species It grows very rapidly in youth, but later more slowly. PLATE XVIII. SCOTCH PINE. 1. A branch with needles and buds, x J. 2. A cluster of two needles, x J. o. Cross-section of two needles, enlarged. 4. Branch with needles; i, immature cone; m, mature cone, x J. 5. A closed cone, x J. 6. A cone scale with two winged seeds, enlarged. 7. A winged seed, enlarged. 8. A seed, enlarged. 9. A seedling, natural size. 10. A small portion of a branch with two pistillate flowers, x j. 11. A branch with a cluster of staminate flowers at the base of the new growth, x J. PLATE XIX. AMERICAN LARCH. 1. Branch with developing leaves and flowers, x J. 2. Branch with needles (clustered and solitary) and fruit, x 4. I. A cone scale with two winged seeds, enlarged. 4. A winged seed, enlarged. 5. A seed, enlarged. 6. A seedling, enlarged. mtural 7. Terminal portion of a winter branch, size. 8. Section of a winter branch, enlarged. 9. A winter branch with lateral spurs, x J. 10. A cone of European Larch (Larix decidua), x *. 11. Leaf of European Larch, x 1. 12. Cross-section of leaf of European Larch, en- larged. 77 AMERICAN LARCH. Larix laricina, (Du Roi) Koch. GENUS DESCRIPTION — This genus comprises about 10 species found in the cooler portion of the northern hemisphere and occasionally extends beyond the Arctic Circle. Of the 10 known species 3 are found in North America, 2 in the western part and 1, a transcontinental species. The latter is found in Pennsylvania. The Larches all shed their leaves every fall and the following spring put out new ones. This deciduous habit gives the trees an appearance in winter of dead conifers. A single foreign species known as the European Larch (Larix decidua Mill.), is planted ex- tensively for ornamental purposes and lately to a limited extent for forestry purposes. It is a very rapid grower and will thrive on drier and less fertile soil than our native eastern species. It should not be planted pure but mixed with other species. FORM — A medium-sized tree usually attaining a height of 30-60 ft. with a diameter of 1-2J ft., but may reach a height of 110 ft. with a diameter of 3 ft. Shrubby towards the northern limits of its range. Trunk straight, continuous, and bearing rather straight, slender, and slightly ascending branches which form in the open a narrow pyramidal crown. BARK — On main trunk rather close but roughened by small, thin, roundish, reddish-brown scales. On the smaller branches it is smooth, thin, bluish-gray. See Fig. 49. TWIGS — At first covered with a bloom, slender, smooth, later becoming dull brown, covered with numerous, short, stout, spur-like lateral branches. BUDS — Occur at end of spur-like lateral branches and along last season's growth; small, about 2/5 of an inch long, globose, smooth, shining, and dark red in color. LEAVES — Linear, triangular in cross-section, I-1J inches long, rounded above, keeled below, and deciduous. They occur either singly along terminal shoots or clustered in fascicles on short spur-like lateral branches. LEAF-SCARS — 'Distinctly decurrent, very small, triangular in outline, and contain a single bundle-scar. FLOWERS — Appear about May with the leaves. Staminate flowers sessile, sub-globose, yel- low, and borne on one or two year old branches. Pistillate flowers short-stalked, oblong, reddish, and borne on lateral branches of previous year. FRUIT — A cone, ovoid, light brown with blunt apex, 5-1 of an inch long, consisting of about 20 scales which are largest near the middle and smaller towards the base and apex. Seeds winged, about J of an inch long and mature in one year. WOOD — Non-porous; somewhat resinous, very heavy, hard, strong, very durable in contact with the soil; heartwood bright red; sapwood narrow and white. Weighs 38.86 Ibs. per cubic foot. Used for fence posts, telegraph poles, railroad ties, and in ship building. DISTINGUISHING CHARACTERISTICS — The American Larch, also known as Tamarack, Hack- matack, and Black Larch, is the only native deciduous conifer of Pennsylvania. In winter it is without leaves and presents the appearance of a dead tree. The leading branches with their spur-like lateral branches bearing tufts of linear leaves in summer and small reddish buds in winter, are characteristic. It bears little resemblance to any of our native conifers but does resemble the European Larch (Larix decidua Mill.) which may be distinguished by its larger cones, stouter and yellower twigs, and longer and more abundant leaves. RANGE — Newfoundland south to Pennsylvania, west to Minnesota and the Rocky Mountains, through British Columbia to Alaska. It is one of our few transcontinental species. DISTRIBUTION IN PENNSYLVANIA — Found locally in moist locations in Carbon, Centre, Clinton, Crawford, Lackawanna, Lycoming, Monroe, Pike, Potter, Tioga and Warren counties. HABITAT — Frequents swamps, banks of lakes and rivers, but also thrives on well drained hill- sides. It is one of the most boreal of eastern conifers, extending north beyond the Arctic Circle to the limit of tree growth. On account of its wide range it experiences great diversity hi climate. Each varied habitat seems to stamp the tree with some peculiarity which is evident in its form and structure. It requires abundant light throughout life. IMPORTANCE OF THE SPECIES — The American Larch is essentially a northern tree but grows naturally in parts of Pennsylvania and may be grown artificially in other parts. The tree is especially adapted for wet locations and hence may be used where other more valuable species will not grow. Seedlings can be grown in the nursery and transplanted with success, but they should not be planted in dry locations. It has a very destructive enemy in a saw fly, which has recently destroyed a large number of trees over an extensive territory in the north- east. THE SPRUCES— PICEA, Link. The Spruces are evergreen trees with stiff, often sharp-pointed needles which persist for 7-10 years. All the species of Spruce found in eastern North America and all but two species found in western North America have four-sided needles. The two exceptions have flattened needles and bear stomata, commonly known as breathing pores, only on the upper surface, while the species with four-sided needles have stomata on all sides. The needles are spirally ar- ranged on the branches and are not stalked but borne on decurrent projections of the bark known as sterigmata. The staminate and pistillate flowers are separate on the same tree, usually on the same branch. The staminate, which bear the pollen, are yellow to red in color, cylindrical in outline, and open lengthwise. The pistillate, which develop into cones, are erect, cylindrical, short-stalked, and pale yellow to scarlet in color. The cones mature at the end of one season and are always drooping and usually cylindrical to ovate in outline. The cones usually fall entire during the first winter or sometimes persist for a few years. They consist of numerous per- sistent cone-scales which are thin and unarmed, and consequently stand in strong contrast with the thick, usually armed, cone- scales of the Pines. The cone-scales are largest near the center and de- crease in size towards the apex and the base. The fertile scales bear two winged seeds on each cone-scale. The seeds are usually light and bear a rather large wing, by means of which they are dissemi- nated over great distances by the wind. The trunks of the Spruces are straight, continuous, and taper gradually to the top. The lumbermen for a long time looked un- favorably upon the Spruces but owing to changed economic condi- tions and a more thorough knowledge of their technical value, these same species are now considered among our most important com- mercial species. The wood of these same species is now considered amongst the most important of the northern hemisphere and espec- ially adapted for the manufacture of paper pulp. The spruce for- ests of North America for a long time remained practically un- touched, but are now being exploited on a gigantic scale. The march of forest destruction is very rapid since an enormous supply is required for the paper pulp industry. In order to supply this growing demand and not diminish the available supply of spruce wood it is necessary that proper and systematic treatment be given to the existing spruce areas, since we cannot hope to import a supply sufficient to satisfy our demand. 79 This genus comprises about 18 to 20 known species, of which num- ber 8 are found in North America, 3 in the eastern part and 5 in the western part. Two of the eastern species are native to Pennsylva- nia. In addition to the native species 2 species, exotic to the State, are commonly planted for ornamental purposes, viz., the Norway Spruce (Picea Abies (L.) Karst.), and Colorado Blue Spruce (Picea pungens Engelm.). The subjoined key will distinguish the Spruces commonly found in Pennsylvania. KEY TO THE SPECIES. Page. 1. Cones cylindrical, over 3 inches long; terminal part of lateral branchlets pendulous; leaves slender, dark green, glossy, sharp-pointed, P. Abies 82 1. Cones ovate to oblong, less than 3 inches long; terminal part of lateral branchlets not decidedly pendulous; leaves rather stout, often blunt-pointed, 2 2.- Leaves dark yellowish-green; cones elongated-ovoid with clear brown, entire-margined scales, P. rubra 80 2. Leaves bluish-green; cones short-ovoid; often persisting beyond iirst season; cone-scales dull, grayish-brown with jagged margin P, mariana 81 80 RED SPRUCE. Picea rubra, (Du Roi) Dietrich. FORM— A medium-sized tree usually reaching a height of 70-80 ft. with a diameter of 1J-2 ft., but may attain a height of 110 ft. with a diameter of 3 ft. Trunk straight, continuous, slightly tapering, bearing long persisting lateral branches which are horizontal in the middle, ascending above and drooping below. Crown narrow, conical in form. BAiRK — Up to i of an inch in thickness and roughened by irregular, • thin, close, reddish- brown scales. TWIGS — Rough, slender, light brown to dark brown, covered with pale to black hairs. BUDS — Ovoid, sharp-pointed, i-i of an inch long, covered by overlapping sharp-pointed reddish-brown scales. LEAVES — About i-i of an inch long, 1/16 of an inch wide, 4-sided, yellowish-green, rounded at apex, crowded, and pointing outward in all directions on twig, without real leaf- stalka but raised on decurrent projections of bark, known as sterigmata. LEAF-SCARS — Small, with a single bundle-scar, borne on decurrent projections of bark. FLOWERS — Appear in April or May. Staminate and pistillate flowers separate, but appear on the same tree. Staminate. oval, almost sessile, reddish in color. Pistillate cylindrical, 1 of an inch long, and consist of rounded thin scales. FRUIT — A cone about 1J-2 inches long, elongated-ovoid, short-stalked, maturing at the end of first season; cone-scales rounded, reddish-brown, with entire margin. WOOD — Non-porous; light, soft, not strong, pale in color, tinged with red, with resin pas- sages present. Weighs 28.13 Ibs. per cubic foot. Used in the manufacture of paper pulp, sounding boards for musical instruments, and construction. DISTINGUISHING CHARACTERISTICS — The Red Spruce, sometimes known as the Spruce Pine, can be distinguished from the Black Spruce by its larger cones, which usually fall during the first winter, while those of the latter usually persist for a longer time. The cone- scales of the Red Spruce are a clear brown and entire-margined, while those of the Black Spruce are grayish-brown and more jagged. The needles of the Red Spruce are dark green to yellowish-green, while those of the Black Spruce are bluish-green. It can readily be dis- tinguished from the White Spruce and the Colorado Blue Spruce by its hairy twigs, and from the Norway Spruce by its much smaller cones and absence of long pendulous branchlets. RANGE — Newfoundland to Pennsylvania and south along the Alleghanies to Georgia, west to Minnesota. Heavy stands occur upon the high mountains of western North Carolina. DISTRIBUTION IN PENNSYLVANIA — Frequents the swamps of Monroe, Pike and a few other counties. HABITAT — Common upon mountain slopes and well drained upland, but also found on moun- tain tops and on the margin of swamps and streams. IMPORTANCE OF THE SPECIES— The Red Spruce is one of the most important species which supply the wood used in the manufacture of paper pulp. Where natural regeneration is pos- sible this species deserves to be developed, especially in places too wet for other species to grow. In this State, the Bear Meadows in Centre county and the lake regions of Pike and, Monroe counties, with their adjoining swamps, give excellent conditions for the natural develop- ment of this species. PLATE XX. RED SPRUCE. 1. Branch with pistil!afe flowers, x I. 2. Branch with staminate flowers, x 1. 3. Branch with needles and cones, x I. 4. A cone scale with two winged seeds, x 5. 5. A winged seed, natural size. 6. A seed, enlarged. 7. Terminal portion of a twig with buds and without needles, natural size. 8. A seedling, natural size. PLATE XXI. BLACK SPRUCE. 1 Branch with pistillate flowers x I 2. Branch with staminate flowers, x'i 3. Branch with needles and cones, x i 4. A cone-scale with two winged seeds, x J. 5. A winged seed, natural size 6. A seed, enlarged. Withoilt 81 BLACK SPRUCE. Picea mariana, (Miller) BSP. FORM— A small tree usually attaining a height of 20-30 ft. with a diameter of 1 ft., but may reach a height of 100 ft. with a diameter of 3 ft. Trunk straight, continuous, very taper- ing, bearing irregular, rather short, horizontal branches, often with ascending tips which give the tree a very narrow, irregular, conic form. BARK — Up to * of an inch in thickness and roughened by irregular, thin, close, grayish- brown scales. See Fig. 51. TWIGS — Rough, stout, brown to yellowish-brown, covered with pale to black hairs. BUDS — Ovoid, sharp-pointed, i-J of an inch long, covered with overlapping, sharp-pointed, reddish-brown scales. LEAVES — About 1-2 of an inch long, 4-sided, bluish-green, rounded at apex, straight or slightly curved, without real leaf-bases, but resting on decurrent projections of bark known as sterigmata. LEAF-SCARS — See "Leaf -Scars" under Red Spruce. FLOWERS — Appear about May. Staminate and pistillate flowers occur on same plant but often on different parts of it. Staminate sub-globose, almost sessile, i of an inch long, reddish in color. Pistillate oblong, cylindrical, i of an inch long. FRUIT — A cone about li inches long, short-ovoid, short-stalked, maturing at the end of the first season; core-scales rounded, dull grayish-brown with jagged margin. WOOD — Non-porous; with resin passages present; light, soft, not strong, pale yellowish- white in color. Weighs 32.86 Ibs. per cubic foot. Used in the manufacture of paper pulp and occasionally in lumber. DISTINGUISHING CHARACTERISTICS — See "Distinguishing Characteristics" under Red Spruce page 80. RANGE — It is a transcontinental species extending from Labrador to Alaska and south to Pennsylvania and Wisconsin. DISTRIBUTION IN PENNSYLVANIA — Frequents swamps, rather common along lakes and in swamps of Monroe and Pike counties and in Bear Meadows, Centre and Huntingdon counties. Also reported in Cambria, Clinton, Lackawanna, Lycoming and Mifllin counties. HABITAT — The Black Spruce, also known as Swamp Spruce, usually frequents cold, poorly drained swamps throughout its range. It sometimes ascends well drained hillsides, but is usually stunted in such situations. It makes its best growth on moist alluvial soils and is very tolerant of shade. IMPORTANCE OF THE SPECIES — The Black Spruce is of little commercial importance in Pennsylvania and should be considered for forestry purposes in extremely swampy locations only, where other more valuable species will not grow. It cannot be recommended for orna- mental planting since other species of Spruce far surpass it for this purpose. NORWAY SPRUCE. Picea Abies, (Linnaeus) Karsten. FORM — A large tree usually attaining a height of 50-80 ft. with a diameter of 2 ft., but may reach a height of 125 ft. with a diameter of 3 ft. Trunk straight, continuous, slightly tapering, and sometimes free from lateral branches for a considerable distance from the base. Crown less acutely pyramidal than that of our native species. BARK — On old trunks roughened with large, rather thick reddish-brown scales; on younger trunks the scales are thinner and closer. Used in tanneries in Europe, but only slightly charged with tannin. TWIGS — Slender, rather pendulous, light reddish-brown and roughened by projecting leaf- BUDS — Ovate to conical, smooth, pointed, covered by overlapping, sharp-pointed, light brown scales. LEAVES — About i-1 inch long, sharp-pointed, 4-sided, dark green, without real leaf-stalks, but resting on decurrent projections of bark known as sterigmata. LEAF-SCABS — See "Leaf -Scars" under Red Spruce. FLOWERS — Appear about May when pollination takes place. Fertilization takes place In June. FRUIT — A cone about 4-7 inches long, cylindrical-oblong, pendant, almost sessile, maturing at the end of the first season; cone-scales thin, stiff, rather broad reddish-brown with finely toothed margin. WOOD — Non-porous; resin passages present; straight-grained, strong, not durable in con- tact with the soil, medium in hardness, works easily, heartwood yellowish-white with thin white sapwood. Weighs 30 Ibs. per cubic foot. Used in the manufacture of paper pulp, general construction, interior finish, basket making and for masts and oars on small vessels. DISTINGUISHING CHARACTERISTICS — The Norway Spruce, also known as the European Spruce, can readily be distinguished by its large cones, which are from 4-7 inches long, and by the long, pendulous branchlets terminating the lateral branches. The sharp-pointed, bluish- green, 4-sided needles will also aid in distinguishing it from some of the other closely related species. RANGE — Its native home is in middle and northern Europe. It forms a very important part of the forest structure of Germany, Switzerland, Austria and Russia. Planted extensively in the United States for ornamental purposes from Maine south to Washington and west to Kansas. DISTRIBUTION IN PENNSYLVANIA — It is found throughout the State as an ornamental tree, and planted rather extensively for forestry purposes by the State Department of Forestry. HABITAT — In Europe it grows in valleys and upon the mountain slopes. It prefers rather rich moist soils, in this respect somewhat resembling the White Pine. It cannot endure very dry, very sterile, or extremely rich vegetable soil. It is rather tolerant of shade and some- what susceptible to late frosts. IMPORTANCE OF THE SPECIES — The Norway Spruce is a foreigner in our forest flora, but before long it will be regarded a naturalized member of our forest structure. It will be an extremely valuable addition to the list of species of forestal significance. To the present time it has been planted mostly for ornamental purposes and for wind breaks, but in the future it will also be planted extensively as a forest tree. It grows rapidly and is rather hardy and free from organic enemies and produces valuable wood. A noted European authority on forestry has said: "Spruce is the best paying forest species in the world." It should be planted as a seedling and preferably mixed with such species as White Pine, European Larch, Douglas Fir, Red Oak, White Ash, and Tulip Tree. It is also possible that it could be grown at a profit for Christmas tree purposes. 10 PLATE XXII. NORWAY SPRUCE. 1. Branch with stamina te flowers, x 1. 2. Branch with pistillate flowers, x J. 3. A needle, natural size. 4. Cross section of a needle, enlarged. 5. Branch with needles removed showing winter buds, x 1. €. Branch with needles and a o<.m>. x \. 7. A cone scale with two winged seeds, natural size. 8 A winged seed, enlarged. 9. A seed, enlarged. l(r. A seedling shedding a seed coat, natural size. 11. A seedling, natural size. PLATE XXIII. HEMLOCK. needles anS— POPULUS (Tourn.) L. This genus comprises about 27 species native to the north temper- ate and arctic zones, of which number 19 are native to North America and 4 to Pennsylvania. The trees belonging to this genus have many common names, as Aspens, Cottonwoods, Poplars, or Popples. Although some of them are called Poplar, still they are in no way related to the well-known Yellow Poplar or Tulip Tree which belongs to the Magnolia family. The leaves of some of the representatives become very conspicuous on account of their trembling or quaking habit. This fluttering of the leaves, even when only a slight breeze is at hand, is due to their laterally compressed leaf-stalks. The buds of a few species are evi- dently resinous and often pungent. Possibly no group of trees, ex- cept the Willows, is so well equipped to disseminate its seeds. The seeds are very light, produced in great abundance, and furnished with a dense covering of long white hairs which aid in their dispersal. The wood of the members of this genus is just beginning to be of commercial importance. It was formerly despised but is now used for various purposes, especially for paper pulp. These trees have some valuable merits in that they grow very fast, often on situations where other species refuse to grow, especially in wet places, and may easily be reproduced by cuttings, sprouts, or seeds. In addition to the 4 species described and contained in the sub- joined key, a few other species are rather common throughout the State especially as ornamental trees. The White or Silver-leaf Poplar (Populus alba L.) is a native of Europe and Asia but very common as an ornamental tree. It can be distinguished by its lobed leaves, covered by a dense white persistent wool on the lower surface, and by its twigs, usually covered with white cottony felt which rubs off easily. The Lombardy Poplar (Populus nigra var. italica Du Koi) is frequently cultivated in this State. It can best be distin- guished by its form (Fig. 36). The lateral branches are almost erect forming! a high but Inarrow urown., The leaves have flattened petioles, are finely toothed, smooth, and sharp-pointed. The Balm of Gilead (Populus candicans Ait.), sometimes regarded a variety of the Balsam Poplar, is occasionally found as a cultivated tree and frequently escapes cultivation. It can be recognized by large resi- nous buds, reddish-brown twigs, and its ovate leaves with round or channeled petioles and heart-shaped base. The leaves of the closely related Balsam Poplar (Populus balsainifera L.) do not have a cor- date base. 95 SUMMER KEY TO THE SPECIES. Page. 1. Leaves with round or channeled petioles; twigs with orange colored pith, P. hetfcrophylla 98 1. Leaves with flattened petioles; twigs with white pith 2 2. Leaves brcadly deltoid, abruptly acuminate; stigina-lobes expanded in all direc- tions, P. deltoides 99 2. Leaves brondly ovate to nearly round, usually acute at apex; stigma-lobes thread- like 3 3. Leaves finely serrate on margin; bark greenish-white P. tremuloides 96 3. Leaves coarsely dentate on margin; bark yellowish-gray to black, P. grandidentata 97 WINTER KEY TO THE SPECIES. 1. Terminal buds i to 1 of an inch long, decidedly resinous; lateral branches with a tend- ency to become vertical, P. deltoides 99 1. Terminal buds about i of an inch long, devoid of resin or only slightly resinous; lateral branches without the vertical tendency 2 2. Twigs with orange-colored pith P, heterophylla 98 2. Twigs with white pith, 3 3. Buds smooth, glossy, conical, sharp-pointed; often incurved and closely appressed, bark greenish-white, P. tremuloides 96 3, Buds downy, dull, ovate, blunt-pointed, straight, divergent; bark yellowish-gray to black P. grandidentata 97 AMERICAN ASPEN. Populus tremuloides, Michaux. FORM — A small tree usually 30-40 ft. high but may reach a height of 80 ft. with a diameter of 20 inches. In Pennsylvania usually very small. Trunk continuous, tapering, bearing slender, brittle, and rather ascending lateral branches. Crown high, narrow, rather round-topped. BARK— On old trunks thick, deeply fissured and black; on upper portion of trunk and young stems yellowish -green to white, with dark blotches below the branches. Usually whiter at high altitude. TWIGS — Rather slender, reddish-brown, glossy, smooth, round, sometimes covered with a scaly bloom; marked by reddish-yellow lenticels; roughened by leaf -scars; pith white and 6-angled. BUDS — Alternate, narrowly conical, sharp-pointed, smooth, shiny, usually appressed, often incurved; covered by 6-7 reddish-brown, smooth, shiny, bud-scales; basal scale of lateral buds outside. LEAVES— Alternate, simple, ovate to nearly round, cordate to truncate at base, acute at apex, finely serrate on margin, 1J-2 inches long, thin, dark green and shiny above, pale green below. Leaf-stalks laterally flattened. LEAF-SCARS — Alternate, large, conspicuous, lunate, with a cork-like surface; bundle-scars 3, simple or compounded. Stipule-scars linear, blackish, rather distinct. FLOWERS — Appear about April. Staminate and pistillate flowers occur on different trees. Staminate aments drooping, 11-2J inches long, bearing many closely packed individual flowers with 6-12 stamcus. Pistillate aments drooping, 1J-2J inches long; when mature 4 inches long, bearing relatively few individual flowers with thick stigmas divided into thread-like lobes. FRUIT — An oblong-conical capsule, 2-valved, light green, borne on a drooping stalk about 4 inches long. Seeds light brown, surrounded by a mat of long, soft, white hairs. WOOD — Diffuse-porous; medullary rays very fine and Indistinct; pores very minute, invisible without a leus. Fine In texture, light brown to white in color, neither strong nor durable. Weighs 25 Ibs. per cubic foot. Used for paper pulp, boxes, Jelly buckets, lard palls, spice kegs, wooden dishes. DISTINGUISHING CHARACTERISTICS — The American Aspen, also known as Quaking Aspen, Trembling Aspen, Small-toothed Aspen, Popple, Poplar, and Aspen, may be distinguished by the round or ovate leaves which have a finely serrate margin and are short-pointed. The petioles of the leaves are decidedly flattened which causes them to tremble or flutter in response to even a light breeze, whence the name Trembling Aspen. The alternate, sharp-pointed, conical, often incurved, closely appressed, shiny buds are also characteristic. The buds of the closely related Larg*-toothed Aspen are stouter, not so sharp-pointed, usually divergent, and covered with a flour-like, crusty, pale, woolly substance. The twigs are reddish and usually smooth while those of the Large-toothed Aspen are yellowish-brown often pale-downy or pale-scaly. The lateral branches ara more ascending and the bark is lighter in color than that of the Large-toothed Aspen. The bark is yellowish-green to white often marked with dark blotches. RANGE— A transcontinental species extending from Newfoundland to the Hudson Bay region and Alaska, south to Pennsylvania and along the mountains to Kentucky, west to the Rocky Mountains, Mexico, and California. The widest range of any species of tree in North America. DISTRIBUTION IN PENNSYLVANIA— Found locally throughout the State. Most common in the mountainous part. HABITAT — Found upon practically ail soil conditions except swamps. Prefers dry situations. Common in abandoned fields, on cut-over areas and burns. Frequently mixed with Scrub Oak which shades out in time. IMPORTANCE OF THE SPECIES — The American Aspen is of no commercial importance in Pennsylvania. It remains too small and is too local in its distribution. Next to Spruce and Hemlock it is the principal pulpwood of the country. It is also beginning to be used for lumber. The wood is white and turns well. Ordinarily it is a poor competitor in the forest but it does overcome the Scrub Oak upon burnt-over areas by shading It out. It is also valuable as a temporary shelter species for other valuable trees. PLATE XXXII. AMERICAN ASPEN. 1. A staminate flowering branch, x i. 2. A staminate flower, enlarged. 3. A pistillate flowering branch, x i. 4. A pistillate flower, enlarged. 5. Section of a fruiting branch, x J. 6. A seed with hairs, enlarged. 7. A branch with mature leaves, x i. 8. A winter twig, x J. 9. Section of a twig with a bud and a leaf- scar, enlarged. PLATE XXXIII. LARGE-TOOTHED ASPEN. 1 A staminate flowering branch, x J. A staminate flower, enlarged. A pistillate flowering branch, x J. A pistillate flower, enlarged. A fruiting catkin with capsules, x J. A seed with hairs, enlarged. A branch with mature foliage, x J. A winter twig, x J. Section of a winter twig, enlarged. 97 LARGE-TOOTHED ASPEN. Populus grandidentata, Michaux. FORM — Usually a small tree 30-40 ft. high but may reach a height of 70 ft. with a diameter of 2 feet. More frequent and larger In this State than the American Aspen. Trunk continuous and tapering. Crown often irregular, due to the absence of branches which have been broken off on account of theii brittleness. Branches usually less ascending than those of the American Aspen. BARK — Near the base of old trunks black, very rough, thick, hard, does not heal over branch wounds rapidly. Large smooth surfaces found on flat ridges between fissures. Smaller branches similar to those of the American Aspen but with a more pronounced yellow color. See Fig. 95. TWIGS — Rather stout, reddish to yellowish-brown, round, often covered with a coating of pale, woolly, crusty down which occasionally peels off in small flakes. BUDS — Alternate, ovate to conical, pointed, dusty, dull, usually divergent, covered by 6-7 light chestnut-brown scales which are often coated with a dusty flour-like mat of a pale, woolly substance. Basa! scale of lateral buds on outside. LEAVES — Alternate, simple, broadly-ovate, wedge-shaped to cordate at base, acute to acuminate at apex, coarsely dentate on margin, 3-4 inches long, dark green above, pale green below. Leaf-stalks laterally flattened. LEAF-SCARS — Same as leaf-scars of American Aspen, page 96. Stipule-scars are less distinct. FLOWEK.S — See "Flowers" under American Aspen, page 96. FRUIT — An ament bearing scattered, light, green, 2-valved capsules which contain minute dark brown seeds surrounded by a mat of long white hairs. WOOD — Same as American Aspen, page 96. DISTINGUISHING CHARACTERISTICS— The Large-toothed Aspen, also known as Popple and Poplar, may be distinguished by its coarsely wavy-toothed leaves, larger than those of the American Aspen which it closely resembles. See "Distinguishing Characteristics" under the latter. It does not have the resinous buds, nor the ridged bark on the twigs, nor the deltoid leaves so characteristic of the Cottonwood. The bark is often covered with oyster-shell-like bodies whicn are the armored portion of the oyster-shell scale. Many small trees are killed by this scale. RANGE — \ova Scotia and Ontario south to Pennsylvania, along mountains to North Carolina and west to Minnesota DISTRIBUTION IN PENNSYLVANIA— Rather common throughout the State especially on lumbered and burnt-over areas, in abandoned fields, and on charcoal hearths. Usually found in mixture, but occasionally in small pure stands. HABITAT — Prefers rather rich moist soil, but is also found on dry gravelly soil. Usually large on moist situations and smaller, often scrubby, on very dry situations. Frequent asso- ciates are Birch, Bird Cherry, Shad Bush, and Scrub Oak. IMPORTANCE OF THE SPECIES— The Large-toothed Aspen is of no commercial importance in this State. It is of value in our lumbered areas because it covers the soil rapidly, acts as a soil-conserver, and often as a soil-improver. It may also act as a temporary shelter for more valuable species while they are young and establishing themselves. It also aids in shading out our most aggressive forest weed — Scrub Oak. 98 DOWNY POPLAR. Populus heterophylla, Linnaeus. FORM — In the north usually a small tree from 30-50 ft. high; in the south may reach a height of 100 ft. with a diameter of 3 ft. Crown high, rather broad and round-topped. Trunk short, con- tinuous, and tapering. BARK — On old trunks thick, light reddish -brown, rough, broken by long fissures into long narrow plates. Cn younger trunks and large branches thinner, not so rough; fissures shallower and ridges smoother than on old trucks. TWIGS— Stout, light yellowish, marked by a few scattered pale lenticels, roughened by elevated leaf -scars; pith orange-colored. BUDS — Alternate, broadly ovate, slightly resinous, bright reddish-brown, covered with 4-7 scales which arc slightly pubescent towards the base. Leaf-buds about J of an inch long. Flower-buds about i of an inch long. LEAVES — Alternate, simple, broadly ovate, cordate, rounded or truncate at base, rounded or acute at apex, coarsely serrate on margin, 4-7 inches long, dark green above, pale green below; leaf -stalks round. LEAF-SCARS— Alternate, large, elevated, often 3-lobed, indented on upper margin; with 3 conspicuous bundle-scars. FLOWERS — .Appear in March or April. In general similar to the Cottonwood only both staminate and pistillate aments are shorter. FRUIT — A drooping ament, when mature about 4-6 inches long, bearing a few, scattered, dark green, 3-4-valved capsules containing small seeds surrounded by a mat of white hairs. WOOD — Same as that of Che Cottonwood only slightly heavier. See description page. 99. DISTINGUISHING CHARACTERISTICS— The Downy Poplar, also known as Swamp Cotton- wood, Black Ccttonwood, River Cottonwood, and Swamp Poplar, may be distinguished from all the Aspens. Poplars, ani Cottonwoods native to this State by its round leaf-stalks. The leaf-stalks of all the others are laterally flattened. The leaves are large and more bluntly pointed than these of the other species. The leaf-margins are not so finely toothed as those of the American Aspen but finer than the other two native species. The bark on old trunks is light reddish browu. The twigs are stouter than those of the Aspens and contain orange colored pith. The Aspens have white pith. The buds are bright reddish-brown, slightly resinous, covered with scales which are often pubescent near the base. RANGE — Connecticut along coast to Georgia, west to Louisiana, and northward to Kentucky and Missouri. Its range suggests a somewhat contorted horseshoe. DISTRIBUTION IN PENNSYLVANIA— Reported from Chester, Delaware, and Franklin counties. Very rare and local. Recent investigations indicate that this species is probably not native to the State. HABITAT — Found only in low wet situations, and always mixed with other species in this State. IMPORTANCE OF THE SPECIES — This species is too rare and local to be of any commercial importance. It is not attractive ornamentally on account of its heavy limbs and sparse, rounded crown. The wood is not listed separately on the market but bought and Bold at Cottonwood. PLATE XXXIV. DOWNY POPLAR. 1. A staminate flowering branch, x J. 2. A staminate flower, enlarged. 3. A pistillate flowering branch, x J. 4. A pistillate flower, enlarged. 5. Section of a branch with a fruiting catkin and capsules, x 1. 6. A seed with hairs, enlarged. 7. A branch with mature foliage, x J. 8. A winter twig, x J. 9. Section of a winter twig, enlarged. PLATE XXXV. COTTONWOOD. 1. A staminate flowering branch, x J. 2. A staminate flower, enlarged. 3. A pistillate flowering branch, x i. 4. A pistillate flower, enlarged. 5. Section of a branch with a fruiting catkin and capsules, x 1. 6. A seed with hairs, enlarged. 7. Section of a branch with mature foliage, x 4. 8. A winter twig, x J. 9. Section of a winter twig, enlarged. 99 COTTONWOOD. Populus deltoides, Marshall. FORM — A large tree usually 50-75 ft. high but may reach a height of more than 100 ft. with a diamoter of 6 feet. Trunk tapering, continuous, sometimes clean for a considerable distance from the ground. Crown usually high and pyramidal. Lower lateral branches horizontal, while most of the upper branches are decidedly ascending. BARK — On old trunks thick, ashy-gray, roughened by long deep furrows which are usually longitudinally parallel, and often connect with one another. Rather thin, smooth, and greenish- yellow on younger trunks. TWIGS — Stout, "usually yellow tinged with green or brown, round or ridged below the buds; covered with large, longitudinally-elongated lenticels; pith white and angular. BUDS — Alterrate, large, resinous, glossy, smooth, chestnut-brown, covered with numerous bud-scales which are sticky, resinous on the interior and smooth on the exterior. Terminal buds often 5-angled and larger than lateral ones; lateral buds usually divergent and often recurved. LEAVES — Alternate, simple, broadly deltoid, truncate to wedge-shaped at base, acuminate at apex, coarsely serrate on margin, 3-5 inches long, thick, deep shining green above, pale green below. Leaf-stalks laterally flattened. LEAF-SCARS — Alternate, large, lunate, elevated, depressed on upper margin, sometimes 3-lobed; with 3 bundle-scars. Stipule-scars dark and conspicuous. FLOWERS— Appear about March or April. Staminate and pistillate flowers occur on different trees. The staminate are arranged in drooping aments 3-4 inches long and are densely flowered; the pistillate, in drooping aments 2J-3J inches long and sparsely flowered. FRUIT — A drooping ament bearing dark green, 3-4-valved capsules which contain small seeds surrounded with a mat of long white hairs. Fruiting aments longer than in the other native species, 8-12 inches. WOOD — Diffuse-porous; with very indistinct rays; pores in early wood visible to unaided eyes; heartwood dark brown; sapwood wide and white; wood is soft, warps easily, and is ditflcult to split. Weighs about 23 Ibs. per cubic foot. Used for paper pulp, boxes, crates, berry boxes, pails, and tubs. DISTINGUISHING CHARACTERISTICS — The Cottonwood, also known as Carolina Poplar, Cotton Tree, and Whitewood may readily be distinguished at any season of the year by its lateral branches which have a tendency to ascend like the Lombardy Poplar (Fig. 36), and by its yellowish twigs which often have prominent ridges running down from the leaf- scars. The bnds are larger, more resinous, and often more flattened than those of any other member of this genus; usually divergent and often incurved. The leaves are very character- istic since they have laterally flattened leaf -stalks, are deltoid in outline, truncate at the base and long-pointed at the apex. The pores in the early wood are visible to the unaided eye while those of the American and Large-toothed Aspens are not visible. RANGE — Quebec and Ontario south to Florida, west to the Rocky Mountains. DISTRIBUTION IN PENNSYLVANIA— Natural distribution is very limited. Reported from Presque Isle, Erie county and from Lancaster county. Locally escaped cultivation. Planted extensively for ornamental purposes and in a few plantations for forestry purposes. HABITAT — Prefers rich moist soil, like banks of streams, borders of lakes, and semi- swamps. IMPORTANCE OF THE SPECIES — The Cottonwood is planted extensively as an ornamental tree but as such it has few merits except its rapid growth, rather attractive form In winter, and the pleasant balsamic odor from its coated, young, developing leaves. It is well adapted to wet locations and may be planted where other more valuable trees will not grow. It grows rapidly, and produces an excellent pulp-wood. This tree is known to grow 5 feet in a single year and 40 feet in 10 years. Cuttings taken from trees and placed in the ground grow very readily. When planted in the streets its roots often lift pavements, and clog drains and sewers. Not adapted for street planting. 100 THE WALNUT FAMILY— JUGLANDACEAE. This family comprises about 6 genera with 35 species of trees and shrubs found chiefly in the warmer portion of the north temperate zone. Two genera with about 19 species are native to North Amer- ica. Both of these genera, Juglans and Carya, have representatives in Pennsylvania. The former genus has 2 species and the latter 5 species native to the State. In addition to the existing species a great number of fossil species have been referred to this family. Thirty fossil species belonging to the genus Juglans .and 10 species belonging to the genus Carya have been described. This is one of the most important families of trees native to Penn- sylvania. Both the Hickories and the Walnuts yield very valuable wood. The wood of the Walnuts is esteemed especially for cabinet work and that of the Hickories on account of its strength and flexi- bility. The bark and husks of the Walnuts are used sometimes as a dyestuff. The fruit of both genera is edible. The staminate and pistillate flowers are separate but borne on the same tree and usually in the same branch. The staminate flow- ers are in long drooping aments while the pistillate appear as buds and occur in small few-flowered clusters. The leaves of both genera are compound and alternate. The fruit is a nut. The nut of the Walnuts is sculptured and covered with a fleshy, indehiscent, pulpy husk while the nut of the Hickories is not sculptured but covered with a dehiscent husk. KEY TO THE GENERA. Page. 1. Pith of twigs chambered; nuts sculptured or rugose with indehiscent husk; staminate catkins thick, compact, usually sessile and solitary; wood diffuse-porous Juglans 101 1. Pith of twigs continuous; nuts smooth or ridged with dehiscent husk; staminate catkins slender, loose, long-stalked, in 3s; wood ring-porous, Carya lOi 101 THE WALNUTS— JUGLANS, L. This genus comprises about 15 species which are found chiefly in the north temperate zone. Five species are native to North Amer- ica, two of which are native to Pennsylvania. In addition to the native species a European species known as the English Walnut (Juglans regia L.) is widely distributed in the Uui&d'v&t&tes as aa ornamental tree. It is this European species which yiejcjs the val- uable Circassian Walnut wood used so extensively3 IF rte/ wai}irfavv ture of furniture and it also produces the English walnuts so com- mon on our markets. Our native species produce materials which are of considerable commercial importance. The wood is highly prized. The nuts are delicious and valuable as a food. The bark and husks are used as dyes and tans. The wood of our species is diffuse-porous and brown to black in color. The leaves are alternate and compound. The pith is chambered. The fruit ripens in one season and consists of a sculptured or rugose nut covered by a pulpy husk which does not split open into regular segments. The kernel of the nut is 2-4 lobed, large and oily. The nuts are scattered mainly by rodents, which bury them for food, and by floods which carry them along their courses. SUMMER KEY TO THE SPECIES. Page. 1. Leaflets 11-17, often viscid-hairy, the terminal leaflet usually present; tpith dark brown; bark gray; fruit sticky-hairy; nut elongated-ovate J. cinerea 102 1. Leaflets 13-23, not viscid -hairy, the terminal leaflet often absent; pith light brown; bark dark brown; fruit not sticky-hairy; nut globose, f J. nigra. 103 WINTER KEY TO THE SPECIES. 1. Bark gray; pith dark brown; nut elongated-ovate; upper surface of leaf -scar not notched; hairy transverse fringe above leaf -scar present; terminal buds evidently , flattened, not less than J of an inch long, J. cinerea 102 1. Bark dark- brown; pith light brown; nut globose; upper surface of leaf -scar notched; hairy fringe above leaf -scar absent; terminal buds slightly flattened, J of an inch or less in length J. nigra 109 102 BUTTERNUT. - ,-. • : j ; Juglans cinerea, Linnaeus. 1 FORM— A small to medivin-sized tree usually attaining a height of 30-50 ft. with a diameter .of 1-jJ ft,., ,tut' may 'ref)'ch a freight of 80-100 ft. with a diameter of 3-4 feet. Trunk usualy short, "like " *Ffft df the s.p.^le', tree. Crown usually broad, deep, round-topped, rather open, often nmsymmetrical.' BARK — On branches and young trunks rather smooth, light gray; on older trunks roughened by black fissures which separate wide, smooth, light gray ridges. Inner bark bitter, light in color, becoming yellow on exposure. See Fig. 80. TWIGS — Alternate, stout, round; at first hairy and sticky, later smooth; roughened by leaf-scars, bitter to taste, greenish-gray to buff in color, covered with a few pale lenticels; pith chambered, dark brown. If chewed, twigs and young bark color saliva yellow. BUDS — Alternate, covered with dense pale down. Terminal bud J-3 of an inch long, flattened, blunt-pointed with its outer scales lobed. Lateral buds smaller than terminal, ovate, very blunt-pointed, often superposed. Scaly cone-like lateral buds often present. These are in reality partially developed catkins. LEAVES — Alternate, compound, 15-30 inches long, with 11-17 leaflets. Leaflets 3-5 inches long, serrate on margin, acute at apex, unequally rounded at base and usually sessile or nearly so. Petioles hairy and sticky. LEAF-SCARS — Alternate, large, 3-lobed, concave, with raised margins, with 3 clusters of bundle-scars arranged in a U-shaped line. Upper margin of leaf-scar usually convex, rarely notched. FLOWERS — Appear about May when leaves are half developed. Staminate and pistillate flowers separate, but occur on the same tree and usually on the same branches. Staminate arranged in nnbranched catkins, which become 3-5 inches long. Pistillate produced in 6-8-flowered spikes. FRUIT — An elcngated-ovate sculptured nut covered with a fleshy indehiscent husk. Husk very hairy and sticky. Nut four-ribbed, pointed at one end; contains a sweet edible and very oily kernel. WOOD — Diffuse-porous with ring-porcus tendency; with inconspicuous medullary rays; soft not strong, light brown, and coarse-grained. Weighs 25.46 Ibs. per cubic foot. Used in furniture, interior finishings, and occasionally in church altars, ceiling, and flooring. DISTINGUISHING CHARACTERISTICS — The Butternut, also known as White Walnut and Oilnut, resembles the Black Walnut, but is distinguished from it by its shorter and light- barked trunk, dark brown pith, larger and more flattened terminal buds, lighter colored wood, elongated-ovate fruit, unnotched upper margin of the leaf-scar with a hairy fringe above it. RANGE — New Brunswick and Quebec, west to Minnesota, and south to Delaware and Arkansas, and along the mountains to Georgia. DISTRIBUTION IN PENNSYLVANIA— Local throughout the State in rich bottomlands and on fertile hillsides. Very common locally in the southeastern and southern parts. HABITAT — Prefers rich moist soil. Common along fences, streams, and roads. Occasionally found on high mountains. IMPORTANCE OF THE SPECIES— The Butternut can hardly be classified as a valuable timber tree. It produces a beautiful wood and delicious nuts but the trees seldom reach a large size. The old trees are very susceptible to the attack of wood-destroying fungi. The tree is attractive ornamentally. It branches freely often forming many crooks and crotches which yield the highly figured wood. PLATE XXXVI. BUTTERNUT. 1. Branch with one-half developed leaves, (s) 3 unbranched catkins of staminate flowers, and (p) a cluster of pistillate flowers, x I. 2. A mature leaflet, x J. 3. A staminate flower, slightly enlarged. 4. A pistillate flower, slightly enlarged. 5. A cluster of mature fruit, x J. 6. A winter twig showing buds, lenticels, leaf- scars, and pith, x J. 7. Longitudinal section of twig showing cham- bered pith, slightly enlarged. 8. Section of winter branch showing leaf-scars, hairy fringe above leaf-scars and superposed buds, slightly enlarged. 9. A nut with husk removed, x |. 10. A terminal bud, natural size. 11. A terminal bud (broad-side view), natural size. 12. Section of a branch showing superposed lat- eral flower buds, enlarged. PLATE XXXVII. BLACK WALNUT. 1. Branch with developing leaves and (s) three solitary catkins of staminate flowers and (p) a spike with three pistillate flowers, x *. 2. A staminate flower, slightly enlarged. 3. A pistillate flower, slightly enlarged. 4. A branch with a mature leaf and fruit, x \. 5. A winter twig, x J. 6. Longitudinal section of twig showing chambered pith, enlarged. 7. Section of twig showing superposed and gaping buds, and leaf-scars with 3 clusters of bundle- scars and notched upper surface, slightly enlarged. 8. A nut with husk removed, x J. 3. Terminal section of winter twig showing leaf-scar and terminal bud with bud-scales, slightly enlarged. 103 BLACK WALNUT. Juglans nigra, Linnaeus. FORM— A large tree, usually attaining a height of 80-100 ft. with a diameter of 2-3 ft., but may reach a height of 150 ft. with a diameter of 6-8 feet. Trunk usually straight, clean, slightly tapering, bearing a round-topped crown. BARK — Semi-fibrous, thick, rough, longitudinally and occasionally diagonally fissured. Outer bark dark brown to grayish-black. Inner bark light, but turns yellow upon exposure. See Fig. 81. TWIGS — At first hairy, later smooth, orange-brown to dark brown, stout, covered with rather inconspicuous, somewhate raised lenticels; pith light brown, chambered. BUDS — Alternate, covered with thick, pubescent scales. Terminal buds usually less than J of an inch long, flattened, ovate, blunt-pointed. Lateral buds usually less than 1/6 of an inch long, obtuse at apex, often superposed. LEAVES — Alternate, compound with 13-23 leaflets. Leaflets 3-4 Inches long, oblique at base, acute at apex, serrate on margin, almost sessile and arranged opposite or alternate to each other. LEAF-SCARS — Alternate, large, 3-lobed, often heart-shaped, raised; upper margin notched in which an axillary bud is often located. Bundle-scars grouped in three clusters, arranged in a U-shaped line. FLOWEHS — Appear in May when the leaves are about half developed. Staminate and pistillate flowers separate, but occar on same tree and usually on same branch. Staminate arranged in unbranched catkins. Pistillate produced in 2-5-flowered spikes. FRUIT — A sculptured nut with a fleshy indehiscent covering. Nut round, very rough, 1-2 inches in diameter, occurs solitary, in pairs, sometimes in 3s; contains an edible somewhat oily kernel. WOOD — Diffuse-porous with a ring-porous tendency; medullary rays inconspicuous; rich dark brown, very durable, hard, strong, splits easily, takes glue well. Weighs 38.11 Ibs. per cubic foot. Used In furniture, interior finishings, musical instruments, automobiles, sewing machines, fire-arms. DISTINGUISHING CHARACTERISTICS— The Black Walnut, also known as Walnut, some- what resembles the Butternut or White Walnut but bears little resemblance to other trees. It may be distinguished from the Butternut by its light brown chambered pith, shorter and less flattened terminal buds, darker bark, larger size, more globose nut, notched upper margins of leaf -scars, and the absence of a hairy fringe above the leaf -scar. RANGE — New England and New York to Minnesota, and south to Florida. DISTRIBUTION IN PENNSYLVANIA— Local throughout the State In rich bottomlands and on fertile hillsides. HABITAT — Prefers rich moist soil. Requires plenty of light and deep soil since it is evidently tap-rooted. IMPORTANCE OF THE SPECIES — The Black Walnut Is one of the most valuable timber trees native to this State. It reaches a large size, is attractive ornamentally, and produces wood valuable for its color, figure, and the fine polish which it takes. The nuts are highly prized. Forest grown trees rarely produce much fruit. Open grown trees produce abundant fruit and often highly figured wood. 104 THE HICKORIES— CARYA, Nuttall. The Hickories and the Walnuts belong to the same family. All species of Hickory, so far as known, are native to the part of North America lying east of the Rocky Mountains. Geological records in- form us that the ancient forests of hickory extended into Greenland and Europe. None of the fossil species shows evidence of living after the ice age. This suggests the presumption that the hickory forests were completely destroyed by sheets of ice advancing from the North towards the South. These sheets covered a large part of Europe and North America. To-day no native species of Hickory are found in Europe, showing that they were completely exterminated during the ice age. In North America the ice covered only a portion of the range of hickory. Hickory is found today not only in the non- glaciated region of North America but in addition it has regained some of the lost territory. The northern limit of Hickory is, how- ever, still about 1,000 miles south of its northern limit in the ancient flora of Greenland. The range of some of the more important species of Hickory has been extended by man. The Hickories have alternate, compound and odd-pinnate leaves. The leaf-scars are large and conspicuous. The flowers 'are unisex- ual. The staminate or male (poll en -bearing) flowers are produced in long slender, drooping aments. The aments are usually in 3s, united near the base of twig into a common stalk which is attached to the twig at the base of the new growth. The pistillate or female flowers which develop into the fruit occur at the end of the season's twigs in spike-like clusters of 2-0. The fruit resulting from the development of the pistillate flowers matures in one season. The nuts are ovoid to cylindrical and covered with a husk which is 4-valved. In most species the husk splits open at least to the middle when it becomes dry but in a few species it separates very little. The Hickories are amongst our most important timber trees. They are not important because they produce a large quantity of wood but because they produce a special quality of wood used for special purposes for which no substitutes have been found. The wood is unsurpassed for such uses where strength combined with lightness is desired. It is largely used for handles and in the manufacture of our best carriages, especially in the construction of the wheels. Not all of the species, however, produce valuable wood. The wood of the Bitter Nut Hickory is relatively of little value. The nuts of a few species are edible. These nuts were used for food and for oil by the Indians and at the present time they are used extensively 105 for food. The most valuable and edible nuts are obtained from the Shag-bark Hickory (Carya ovata). This genus comprises about 10 species found in eastern North America and 1 species in Mexico. Six species are native to this State. One species, the small-fruited Hickory (Carya microcarpa, Nutt. ) , sometimes considered a variety of the Pignut Hickory, is found locally in the State but not described in this publication. In addi- tion to our native species the Pecan Hickory (Carya illinoensis) is planted extensively for ornamental purposes and for the sweet nuts which it produces. SUMMER KEY TO THE SPECIES. Page. 1. Leaflets 7-11, small, lanceolate, usually curved C. cordiformis 110 1. Leaflets 5-7, larger, broader than lanceolate, rarely curved 2 2. Husk of fruit splits tardily into 4 valves; valves of fruit thin and rather friable at maturity; twigs smooth, relatively slender, cherry-colored to gray 0. glabra 109 2. Husk of fruit splits promptly into 4 valves; valves of fruit thick and hard at maturity; twigs often hairy towards tip, rather stout, buff, gray, or brownish 3 3, Bark closo, rough but not shaggy on old trunks; twigs relatively stout; foliage scurfy or pubescent C. alba 108 3. Bark shaggy separating into long plates on old trunks; twigs not so stout; foliage smooth -or sometimes downy beneath, 4 4. Leaflets usually 7; nuts dull white or yellowish and pointed at both ends, C. laciniosa 107 4. Leaflets usually 5; nuts white, rounded or notched at the base, C. ovata 106 WINTER KEY TO THE SPECIES. 1. Buds yellow with 4-6 bud-scales valvate in pairs; lateral buds often evidently- stalked; terminal buds elongated and flattened C. cordiformis 110 1. Buds not yellow, truly scaly; bud-scales 10 or more usually overlapping, except outer ones on lateral buds which may form a closed sac but in time split from the top; inner scales, hairy, 2 2. Buds small; terminal buds 1/5 to 2/5 of an inch long, their outer scales glandular dotted; twigs smooth, relatively slender, cherry-colored to gray; husk of fruit thin, not freely splitting to base, with thin-shelled nut,, .- C. glabra 109 2. Buds large; terminal buds 2/5 to 3/5 of an inch long, their outer scales almost glandless; twigs often hairy towards tip, rather stout, buff, gray, or brownish, husk of fruit thick, freely splitting to base 3 3. Twigs relatively stout; bark rough and close, not shaggy; nut brownish, thick- shelled, with small kernel; terminal buds broadly-ovate with their outer scales early deciduous, , C. alba 108 3. Twigs not so stout; bark shaggy; nut white, 'dull-white, or yellowish with large kernel; terminal buds elongate-ovate with their outer scales tardily deciduous 4 4. Nuts dull white or yellowish and pointed at both ends C, laciniosa 107 4. Nuts white, rounded or notched at the base, 0. ovata 106 100 SHELL-BARK HICKORY. Carya ovata, (Miller) K. Koch. FORM— A large tree usually reaching a height of 50-75 ft. with a diameter of 2 ft. but may reach a height of 120 ft. with a diameter of 3-4 feet. Trunk straight, slender, in dense stands free from branches for the greater part of its length; in open grown trees short, with an oblong-cylindrical high crown. BARK — On old trunks shaggy, light gray, 2/5-1 inch thick, peeling off in rough strips or plates which are usually loose at both ends and fastened in the middle. On young trunks smooth and light gray. See Pig. 88. TWIGS — Intermediate in thickness between the Mocker Nut and the Pignut Hickory, usually slightly downy, sometimes smooth anl glossy; reddish-brown to grayish, covered with numerous conspicuous and longitudinally-elongated lenticels; pith angular. BUDS — Alternate, more than 2-ranked. Terminal bud broadly ovate, blunt-pointed, 2/5-4/5 of an inch long, usrally covered by about 10 bud-scales. The 8-4 outer scales dark brown, broadly triangular, sharp-pointed, often hairy especially along margin, sometimes smooth, and often with the apex terminating in a long rigid point. Inner scales increase In size in spring, are tardily deciduous, yellowish -green or reddish, densely downy on outer surface and smooth within. LEAVES — Alternate, compound, with 5-7 leaflets, 8-14 inches long. Leaflets differ In size; basal pair small, relatively short and widest near the base; upper pair obovate and larger than basal pair; terminal large and obovate. Leaflets serrate on margin, acute at apex, tapering or rounded at base, usually smooth but sometimes hairy on lower surface. LEAF-SCARS — Altornate, more than 2-ranked, large, conspicuous, somewhat raised, heart- shaped or 3-lobed or inversely-triangular or sometimes elliptical, containing numerous con- spicuous bundle-scars which are distributed irregularly or grouped in 3 clusters or arranged In a curved line. FLOWERS — Appear about May when leaves are almost fully developed. Staminate and pistil- late flowers occur separately. Staminate hairy and arranged In aments which are clustered In 3s and 4-5 inches long. Pistillate rusty-woolly arranged in 2-5 large spikes. FRUIT — Globular or depressed at apex, 1-2 inches long, with a thick husk which splits into four pieces completely to the base. Nut white, oblong, somewhat flattened, ridged, barely tipped with a point, with thin shell and large sweot kernel. WOOD — Ring-porous; pores of summer wood rather large, isolated, rather evenly distributed, not in groups or lines; medullary rays rather abundant but Inconspicuous; conspicuous lines of wood parenchyma present. Wood very heavy, hard, strong, tough, elastic, close-grained, usually straight-grained, not durable in contact with soil. Heartwood light brown or reddish with white sapwood. Weighs from 50 to 52 Ibs. per cubic foot. Used chiefly for handles and light vehicles. Valuable for fuel and smoking meat. DISTINGUISHING CHARACTERISTICS — The Shell -bark Hickory, also known as Shag-bark Hickory, can be distinguished from the Bitter Nut Hickory by means of its larger many-scaled buds which are not flattened nor yellow, and by its bark which is shaggy, while that of the latter is close and rough. The bark of the Pignut Hickory, is also close and rough. The Pignut Hickory has scaly buds but they are much smaller than those of the Shell-bark Hickory. The fruit of both the Pignut Hickory and Bitter Nut Hickory Is smaller and has a thin tardily or non-splitting husk and a small bitter kernel, and their leaves are smoother and their leaflets narrower than those of the Shell-bark Hickories. The Mocker Nut Hickory has stouter twigs, scurfler pubescent foliage, closer and rougher bark, and browner nuts with a small kernel. For distinguishing characteristics between Carya ovata and Carya laciniosa, see page 107. RANGE — Quebec west to Minnesota and south to Florida and Texas. DISTRIBUTION IN PENNSYLVANIA — Most common in the southeastern and southwestern parts of the State. Rare in the mountainous parts, except locally In the valleys. Rather abundant lo- cally east of the Allegheny mountains especially in the fertile valleys and along the rich foothills. Reported rather abundant locally in the northern part. HABITAT — Prefers rich moist soil and plenty of light. Common In the valley and in moist hillside woods. Also common along streams, and on the border of swamps. IMPORTANCE OF THE SPECIES — This Is a very important species on account of the valuable wood and nuts which It produces. It is not very common in the State as a whole, but where it does occur it should be protected and regenerated as much as possible. Seeds should be planted rather than seedlings because the latter are sensitive to transplanting on account of their long taproot. PLATE XXXVIII. SHELL-BARK HICKORY. 1. A flowering branch, x J. . 2. A branch with fruit and a mature leaf, x i. 3. A nut with part of husk removed, x J. 4. A nut, x J. 5. Cross-section of a nut showing kernel, x J. 6. A winter twig, x J. 7. Terminal part of a winter twig, natural size. 8. Section of a winter twig showing a lateral bud and leaf-scar, enlarged. PLATE XXXIX. BIG SHELL-BARK HICKORY. 1. A flowering branch, x 5. 2. A branch with fruit and a mature leaf, x i. 3. A nut, x J. 4. Cross-section of a nut, x J. 5. A winter twig, x J. 6. Terminal part of a winter twig, slightly enlarged. 7. A leaf -scar with bundle-scars, slightly enlarged. 107 BIG SHELL-BARK HICKORY. Carya laciniosa, (Michaux f.) Loudon. FORM — In general it is the same as the Shell-bark (Carya ovata) except that it does not attain so large a diameter. When grown in a dense forest its trunk is very long, clean, and slightly tapering. BARK — Same as Shell-bark Hickory (Carya ovata) or probably somewhat less shaggy. TWIGS — Stout, usually a little velvety or tomentose, buff to nearly orange in color, covered with numerous rather inconspicuous longitudinally-elongated lenticels; pith angular. BUDS — Similar to thos.e of the shell-bark (Carya ovata) except that they are a little larger and have less keeled and more hairy outer scales. LEAVES — Alternate, compound, with 7-9 leaflets, 10-22 inches long. Leaflets differ in size; basal pair smallest, about i size of the terminal; the upper pair broadest between the middle and the apex. Leaflets sharp-pointed at apex, serrate on margin, tapering or rounded at base, thick, firm, dark green and smooth above, pale green to brownish and hairy below. Leaf-stalks grooved, stout, smooth or hairy, thickened at base, often persist for a long time. LEAF-SCARS — Alternate, more than 2-ranked, large, conspicuous, somewhat raised, heart-shaped or 3-lobed or inversely triangular or sometimes elliptical, containing numerous conspicuous bundle- scars which are distributed irregularly, grouped in 3 clusters or arranged in a curved line. FLOWERS— Similar to those of Shell-bark Hickory (Carya ovata). See page 106. FRUIT— Ovoid or broadly-oblong, 4-ribbed above the middle, covered with very thick husk which splits readily to the base. Nut dull white or yellowish, thick-walled, usually strongly pointed at both ends, containing a sweet, light brown and deeply lobed kernel. WOOD — Similar to that of the Shell-bark (Carya ovata), see page 106. Lumbermen do not and manufacturers cannot distinguish between the wood of the two species. DISTINGUISHING CHARACTERISTICS— The Big Shell-bark Hickory, also known as Shag-bark Hickory and King Nut, is most closely related to the Shell-bark Hickory (Carya ovata). It can best be distinguished by its dull white or yellowish nuts which are usually strongly pointed at both ends, while those of the latter are white and barely tipped with a point and often rounded or notched at the base. The leaflets of this species number 7-9 to a leaf and are more downy on the lower surface than in Carya ovata which has only 5-7 leaflets to each leaf. For distinguishing char- acteristics between this species and other Hickories see "Distinguishing Characteristics" under Carya ovata, page 106. RANGE — Central New York and Pennsylvania west to Iowa and Nebraska and south to Ten- nessee and Arkansas. DISTRIBUTION IN PENNSYLVANIA— Common in the southeastern part of the State. Most common east of the Allegheny mountains. Rare in the mountainous region except locally In the fertile valley between the mountains. Locally present in the western part. Probably most com- mon in Northampton, Bucks and Montgomery counties. HABITAT — Prefers wet, rich soil. Often found on situations which are temporarily flooded in spring. Frequent in rich bottomlands and on fertile hillsides. IMPORTANCE OF THE SPECIES — This is a very important species on account of the valuable wood and nuts which it produces. It is not very common in the State as a whole, but where it does occur it should be protected and regenerated as much as possible. Seeds should be planted rather than seedlings because the latter are sensitive to transplanting on account of their long taproot. 108 MOCKER NUT HICKORY. Carya alba, (Linnaeus) K. Koch. FORM— A large tree usually 50-75 ft. high with a diameter of about 2 ft. but may reach a height of 90 ft. with a diameter of 3 ft. Crown narrow oblong to broad round-topped. Trunk often swollen at base, in dense stands straight, clean, with little taper and free from branches for one- half of its height. BARK — Dark or light gray, 5-1 of an inch thick, close, not shaggy nor smooth, roughened by Irregular furrows which separate broad, flat, close, more or less scaly and rounded ridges. See Fig. 90. TWIGS — Compared with the other Hickories very stout, usually decidedly downy, reddish-brown, covered with numerous pale and longitudinally-elongated lenticels; pith angular. BUDS — Alternate, more than 2-ranked. Terminal bud very large, ovate, 2/5-4/5 of an inch long, densely hairy, usually blunt-pointed, covered with overlapping scales, the outer pair of which drops oft" in autumn and exposes the inner yellowish-gray silky scales. Lateral buds reddish- brown and do not split open very early. LEAVES — Alternate, compound with 7-9 leaflets, 8-12 inches long. Leaflets lanceolate-obovate, sharp-pointed at apex, toothed on margin, rounded or tapering at base, very fragrant, often downy on lower surface. Leaf-stalks hairy, flattened, grooved, and enlarged at base. Upper pair of leaflets largest with greatest width between the middle and the apex; lower pair often oblong- lanceolate. LEAF-SCARS— Similar to those of Shell-bark Hickory (Carya ovata). FLOWERS — Appear about May when the leaves are half developed. Staminate and pistillate flowers separate. Staminate borne in slender catkins 4-5 inches long, which are clustered in 3s en a common stalk. Pistillate borne in 2-5-flowered pale hairy spikes. FRUIT — Globular or ovoid, 15-2J inches long, with a very thick or hard husk which splits to the middle or base. Nut globular, brownish, not evidently-flattened but 4-ridged towards apex, with a very thick shell and comparatively small and sweet kernel. WOOD — Similar to that of the Shell-bark Hickory (Carya ovata). See description page 106. Has a somewhat wider sapwood which is very white in color whence its specific name — alba. Heartwood dark brown. DISTINGUISHING CHARACTERISTICS— The Mocker Nut Hickory, also known as the Bull Nut Hickory, the Big Bud Hickory and the White-heart Hickory, can be distinguished from the two species of Shell-bark Hickory by its bark, which is rough and close and does not shag off, its stouter twigs, its scurfy pubescent foliage and its globular fruit which contains a globular brownish thick-shelled nut with a relatively small kernel. The buds are somewhat larger than those of the Shell-bark Hickories and thicker than the Pignut and Bitter Nut. The kernel of the latter two species is bitter and their leaflets are narrower and smoother. RANGE — Massachusetts and Ontario, west to Nebraska, and south to Florida and Texas. DISTRIBUTION IN PENNSYLVANIA— Found most commonly in the rich valleys in the east- ern and southern parts of the State with local outposts in the central part. Also found in the hardwood forest region in the western part. HABITAT— Prefers rich, moist woods. Requires considerable moisture and sunlight. Does not thrive in shaded situations. Found mainly in valleys and in fertile situations at the bottom of slopes. IMPORTANCE OF THE SPECIES— This species produces as valuable a wood as any of the Hickories. Some think that the wood is better than that produced by our other native Hickories because of the large amount of white sapwood. It is difficult to transplant on account of its long taproot, hence it is advisable to plant the seeds rather than seedlings. Every effort which one puts forth in developing and perpetuating this species in our forests, especially in the farmer's woodlot, is Justified. The fruit is large but the kernel Is small and as a consequence it has no special market value. PLATE XL. MOCKER NUT HICKORY. 1. Branch with immature leaves and flowers, 2. Branch with a mature leaf and fruit, x J. 3. A nut with husk removed, x J. 4. Longitudinal section of a nut, x J. 5. A winter branchlet, x J. 6. A winter branchlet, slightly enlarged. 7. Section of winter branch, enlarged. 8. Section of winter branch, enlarged. x 5. PLATE XLI. PIGNUT HICKORY. 1. Branch with immature leaves and flowers, x |. 2. Branch with mature leaves and fruit with husk partly removed, x 3. A nut with husk removed, x |. 4. Cross-section of a nut, x I. 5. A winter brancn, x J. 6. Terminal section of a winter branch, enlarged. 7. A leaf-scar with bundle-scars, enlarged. 109 PIGNUT HICKORY. Carya glabra, (Miller) Spach. FORM — A fair-sized tree usually 50-60 ft. in height with a diameter of 2-3 ft., but may reach a height of 90 ft. with a diameter of 3-4 ft. Trunk slender, slightly-tapering, often clean and long. Crown oblong in shape, rather narrow, sometimes high, formed by short, spreading branches, the lower ones often drooping. BARK — Rarely peels off or exfoliates, is close, dark gray, shallowly -fissured, narrowly ridged, tough, J-l of an inch thick. Resembles the bark of the White Ash. See Fig. 89, TWIGS — Rather slender, usually smooth, at first yellowish-green, later reddish-brown, covered with numerous pale longitudinally-elongated lenticels, roughened by leaf-scars and bud-scale scars; pith angular. BUDS — Alternate, more than 2-ranked, reddish-brown to gray, oval, blunt-pointed. Terminal bud J-J of an inch long, larger than the laterals. All buds covered with reddish-brown, smooth, sharp-pointed, somewhat keeled outer scales and pale-silky inner scales. Outer scales often drop off during winter. LEAVES — Alternate, compound, with 5-7 leaflets, 8-12 inches long. Leaflets oblong to obovate- lanceolate, sharp-pointed at apex, finely toothed on margin, tapering or obliquely rounded at base, thick, smooth, dark green above, paler below. LEAF-SCARS — Alternate, heart-shaped or oblong or inversely triangular or 3-lobed, contain- ing numerous prominent bundle-scars irregularly scattered or arranged in a curved line or In 3 clusters. FLOWERS — Appear about May when leaves are about half developed. Staminate and pistillate flowers occur separately. Staminate in aments about 3-5 inches long and clustered in 3s on a common stalk. Pistillate in 2-5-flowered spikes on the new growth. FRUIT — Matures about October, variable in shape and size, pear-shaped or spherical to obovoid, 1-2 inches long, tapering at the base, reddish-brown, sometimes pubescent. Husk may remain closed or split open from apex towards the middle or occasionally along the entire length. Nut; oblong to oval, with thick bony shell containing a kernel which is at first sweet, later bitter. WOOD— Similar to that of the other Hickories of the State, except the Bitter Nut Hickory. See description of wood page 106. DISTINGUISHING CHARACTERISTICS— The Pignut or Broom Hickory, also known as the Bitter Nut Hickory, can be distinguished by its smooth and rather slender twigs which bear small oval reddish-brown buds covered with scales, the outer hair of which is smooth or glandular' dotted and often falls off before spring, thus exposing the inner velvety scales. Its buds are not yellow like those of the Bitter Nut Hicku.-y and smaller than those of the other species of our native Hickories. The pear-shaped to ovoid fruit, with a thick bony-shelled nut is characteristic.' The bark 13 close and does not exfoliate like that of the Shag-bark Hickory. The leaves, with 5-7 usually smooth and oblong to obovate-lanceolate leaflets, are distinctive. RANGE — Maine and Ontario west to Minnesota and Nebraska, and south to Florida and Texas. DISTRIBUTION IN PENNSYLVANIA— Common in the southeastern and southwestern parts. Also fcund locally elsewhere. More common in the mountainous portion of the State than any other Hickory. HABITAT — Most common on dry ridges and hillsides. Rarer in swampy situations. Commonly scattered amidst our Oaks and Chestnut. Prefers plenty of sunlight. IMPORTANCE OF THE SPECIES— The Pignut Hickory produces a very valuable wood, espe- cially for the farmer. The fruit is not edible. It should be grown in the farmer's woodlot and in our larger forests in mixture with other species. The seedlings are difficult to transplant on account of their long taproots, which are rather sensitive. In attempting to grow this species, one should plant the nuts and not the seedlings. The great value of its wood justifies every effort that one can put forth in growing it. 110 BITTER NUT HICKORY. Carya cordiformis, (Wangenheim) K. Koch. FORM — A rather large tree usually 50-75 ft. high with a diameter of 1-2 ft. but may reach a height of 100 ft. with a diameter of 25-3 feet. Trunk long, clean, with little taper. Crown round-topped, broadest near top, rather shallow in forest grown specimens. Lateral branches stout and ascending, often with semi-pendulous branchlets. BARK — Light gray, rather thin, roughened by shallow fissures and narrow ridges; tight- fitting and does not peel off or shag off 1n loos? scales like the Shag-bark Hickory. See Fig. 01. TWIGS— Slender, smooth, glossy, often yellow-glandular and hairy towards apex, grayish or orange-brown or reddish, roughened with numerous pale and longitudinally-elongated lenticels: pith brown, angular. BUDS — Alternate, covered by 4 yellowish, glandular-dotted scales occurring in valvate pairs. Terminal bud evidently-elongated, flattened, blunt-pointed. Lateral buds usually superposed; the lowest or axillary one usually small and sharp-pointed; the upper one larger, evidently- stalked and angular. LEAVES — Alternate, compound, with 7-11 leaflets, 6-10 inches long. Leaflets lanceolate to ovate-lanceolate, lateral ones sessile, sharp-pointed at apex, finely toothed on margin, obliquely tapering or heart-shaped at base; when mature dark yellowish-green above, paler below. LEAF-SCARS — Alternate, large, conspicuous, raised, heart-shaped, triangular to elliptical, lighter than twigs, containing numerous bundle-scars arranged in 3 groups or in a single curved line or occasionally scattered irregularly over whole scar. FLOWERS — Appear about May when leaves are half-developed. Staminate and pistillate flowers separate. Staminate green and arranged in triple-clustered aments about 3-4 inches long. Pistillate, and small clusters on the new growth about 2 of an inch long, somewhat angled and scurfy-hairy. FRUIT — Matures about October; spherical to obovate about f-li inches long. Husk thin, yellowish glandular-dotted, splits open to about the middle into four valves; before splitting appears 4-winged from apex to about the middle. Nut thin-shelled, at least as broad as long, smooth, short-pointed, with reddish-brown and very bitter kernel. WOOD — Wood of this species resembles the wood of the other Hickories, described on page 106, only it is somewhat lighter, not quite so strong, of somewhat less fuel value, more brittle, less stiff, and yields more ash when burned. DISTINGUISHING CHARACTERISTICS— The Bitter Nut Hickory, also known as Tight Bark Hickory, Swamp Hickory and Bitter Hickory, can be distinguished by its lanceolate leaflets which are pubescent beneath, and smaller than those of any other native Hickory. It is the only native species which has yellow buds with 4-6 bud-scales arranged in valvate pairs. Its terminal buds are flattened and elongated while the lateral buds are evidently-stalked and superposed. The nut is globular, short-pointed, thin-walled, containing a bitter kernel, and is covered by a thin husk which in time splits open from the apex to about the middle. The bark is rough, but does not scale off, which characteristic it has in common with the Pignut and the Mocker Nut. RANGE — Quebec to Minnesota and Nebraska and south to Florida and Texas. DISTRIBUTION IN PENNSYLVANIA — Local throughout the eastern and southern parts. Com- mon in the southwestern part. Also reported from the central and northern parts. Usually solitary and scattered. HABITAT — Prefers low, wet, and fertile situations such as border of streams and farmers' woodlots located in rich agricultural regions. Often found, however, far up the slopes of moun- tains. It ascends to the top of the South Mountains in Pennsylvania. Not very tolerant of shade. IMPORTANCE OF THE SPECIES — This species produces valuable wood but its fruit Is not edible. It grows best on rich moist ooil such as one usually finds in a farmer's woodlot. It endures transplanting better and grows more rapidly than any other of our Hickories. This valuable wood is becoming rare. A future supply should be insured by developing this tree in mixture with others in the farmer's woodlot and in fertile portions of larger forests. It is not gregarious but prefers to grow as a single specimen in mixture with other species. PLATE XLII. BITTER NUT HICKORY. 1. Branch with immature leaves and flowers, x *. " ^ 2. Branch with a mature leaf and fruit, x |. \^ 3. A fruit with husk partly opened, x *. 4. A nut with husk removed, x J. , "• ., 5. Longitudinal section of nut, x i. • • •* "*•, 6. A winter branch, x i. jS' -. » , 7 Section of winter branch showing superposed buds, slightly enlarged. S. Section of winter branch showing superposed buds and leaf-scar, slightly enlarged. 9. A leaf -scar with bundle-scars, enlarged. Ill THE BIRCH FAMILY— BETULACEAE. The Birch family comprises 6 genera with about 75 species of trees and shrubs which are confined to the colder part of the northern hemisphere. Of this number 5 genera with about 30 species are native to North America and 5 genera with 11 species to Pennsylva- nia. All the members of this family, even though they may belong to different genera, have many morphological features in common. The leaves are simple, alternate, borne singly or in pairs on the branches but never opposite each other. The staminate and pistillate flow- ers are separate, but are borne on different parts of the same tree and usually on different parts of the same branch. The staminate flowers are long, usually in drooping aments, or in spike-like or knob- like aments and may be with or without a perianth. The fruits are small, one- celled, usually subtended by a large bract which in the most important genera develops into a cone-like structure called a strobile. Various products of high commercial importance are produced by this family. The wood of the Birches is used extensively for furni- ture, flooring, interior finishing and has a very high fuel value. The fruit of the Hazelnuts is prized as food. The wood of some of the Alders is especially adapted to the manufacture of gunpowder and charcoal. The bark of the Black Birch yields a volatile oil of consid- erable importance. The technical value of the products from the members of this family are becoming more important every year. The wood of some of the species which was despised formerly, is now considered of high value in some particular industries, on account of the new uses to which it is being put. The science of Xylology, which is merely in its formative period, will do much in advancing the position of the wood of species at present despised or at least not fully known. The subjoined key will aid in distinguishing the genera of this family. KEY TO THE GENERA. Page. 1. Staminate flowers solitary on each bract; pistillate flowers with a perianth; fruit not a. strobile 2 1. Staminate flowers 2 to several on each bract; pistillate flowers without a perianth; fruit i\ strobile 4 2. Shrubs: twigs covered with stiff red hairs standing out at right angles; nuts large covered by leaf-like Involucre Corylus 122 2. Trees: Twigs not covered with stiff red hairs; nuts small and subtended by a large bract 3 3. Bark close, smooth and fluted; nut subtended by a flat 3-lobed bract, terminal lobe serrate on one side, Carpinus 120 3. Bark thin covered by loose ribbon-like narrow brown scales; nut subtended by a closed bract arranged In hop-like clusters Ostrya 119 4. Shrub with close, somewhat fluted bark; wood yellowish upon exposure; buds stalked, obtuse at apex, covered with two exposed valv«te scales; fruit woody and persistent Ainu* 121 4. Small to large trees with loose bark usually peeling off into thin film-like layers; buds not stalked, acute at apex, covered with 3 or more overlapping scales; fruit membranous and deciduous, Betula 112 112 THE BIRCHES— BETULA, Tournefort (L.) This genus comprises about 35 known species of which number 25 are trees and the others shrubs.. Of the known species about 15 are native to North America and 5 to Pennsylvania. The members of this genus are without exception called Birches. In most of them the bark of the trees when young is ' smooth and peels off into film-like papery layers which vary in color according to the species from chalky white to reddish-brown. A few species have, however, a close and smooth bark which does not peel off into thin film-like papery layers. The wood is dense and hard, does not show the annual rings very clearly, is of high fuel value and usually reddish-brown in color, sometimes possessing a highly prized curly or wavy figure. The twigs of the season produce only one leaf at a point, while the twigs of the previous season produce two leaves from the lateral buds situate on the short spur-like branches. The leaves are simple, always alternate, occur singly or in pairs but never op- posite. The flowers appear before or with the developing leaves. The staminate flowers appear clustered in long tassel-like bodies hanging down from the end of the twigs and are known as aments. The pis- tillate flowers appear below the staminate and are nearly erect, rather small and slender. The fruit is a cone-like structure known as a strobile consisting of a central axis to which numerous scales are attached. The scales are thin, 3-lobed, and bear the small flat nuts with their wings. The nuts are very light and easily scattered by the wind for considerable distances from the mother or seed trees. The commercial products derived from some of the members of this genus are rather important and valuable. The species found in the eastern part of North America yield products of more value than those found in the western part. Most of the species found in the western part of North America are too small, or infrequent in the form of stands, to be commercially important for general or even domestic use. Some of the species found in the eastern part of North America are also small shrubs but others reach the size of large tim- ber trees which yield not only excellent wood but also valuable oils, flavors, and bark. The subjoined key will aid in distinguishing the species of Birch found in Pennsylvania. Separate summer and winter keys were not developed since the following key is based primarily upon bark char- acteristics which are present at all seasons of the year. 113 KEY TO THE SPECIES. Page. 1. Bark usually separating Into thin film-like papery layers 2 1. Bark close, not separating into thin film-like papery layers, 4 2. Outer bark white in color, B. alba var. papyriffcra 114 2. Outer bark not white in color. 3 3. Outer bark yellow in color; strobiles usually sessile; leaves usually rounded at base , ; ; B. lutea 115 3, Outer bark reddish-brown, close, inner bark tinged with red; strobiles slender- stalked; leaves usually wedge-shaped at base B. nigra 116 4. Bark chalky white covered with black triangular spots below insertion of lateral branches; small tree, often in clumps; leaves long-acuminate, B. populifolia 117 4. Bark dark reddish-brcwn; large tree, usually occurs singly; leaves ovate with acute apex; twigs and inner bark with wintergreen-like taste, i..... — B, lenta 1H 8 114 PAPER BIRCH. Betula alba var. papyrifera, (Marshall) Spach. FORM— A large tree usually attaining a height of 50-75 ft. with a diameter of 1-2 ft., but may roach a height of 80 ft. with a diameter of 3 feet. Trunk in open grown trees short and covered nearly to the base with lateral, often ascending branches; in close stands branchless below and bearing a narrow open head. BARK — On trunk and older branches chalky to creamy white and peeling off in thin film- like layers which are tinged with yellow and covered with horizontally-elongated lenticels. On older trunks rough and often fissured into irregular thick scales. TWIGS — Rather stout, somewhat viscid, decidedly hairy, at first greenish, later becoming smooth, reddish-brown, and" after several years, bright white, like the trunk, covered with pale, horizontally-elongated, orange-colored lenticels. BUDS — Alternate, ovate, sharp-pointed, divergent, about 1 of an inch long, dark chestnut- brown in color, covered by a few overlapping bud-scales with downy margins. LEAVES — Alternate, simple, ovate, 2-3 inches long, 15-2 inches wide, rather firm in texture; upper surface dark green, under surface light green; narrowed or rounded at the base, sharply toothed on the margin and sharp-pointed at the apex. LEAF-SCARS— See "Leaf -Scars" under Black Birch, page 118. FLOV7ERS — Appear in April or May before the leaves. The staminate are arranged in aments, which occur in groups of 2-3 and are about J to 1$ inches long, becoming 3J-4 inches long in spring. The pistillate have light green lanceolate scales and bright red styles, and are arranged in clusters about 1-11 inches long. FRUIT — A cylindrical, short-stalked strobile about 13 inches long. Scales long, with thick lateral lobes and a rather long terminal lobe. Seeds small and winged. Wings wider than the nut. WOOD — Diffuse-porous; rays small and inconspicuous; light, strong, hard, light brown tinged with red, with rather thick, light sapwood. Weighs 37.11 Ibs. per cubic foot. Used exten- sively for spools, shoe lasts, pegs, fuel, and in the manufacture of paper^pulp. DISTINGUISHING CHARACTERISTICS— The Paper Birch, also known as Canoe Birch and White Birch, may readily be distinguished from all the other species of Birch in Pennsyl- vania except the Gray Birch, by its characteristic white bark, which is never renewed when once removed. The European White Birch, which is introduced extensively for ornamental pur- poses, also has a white bark. To distinguish it from the Gray Birch see "Distinguishing Characteristics" under Gray Birch. RANGE — From Newfoundland to Alaska, south to Penrsyivania, Michigan, Colorado, and Washington. This is one of the few transcontinental species. DISTRIBUTION IN PENNSYLVANIA— Found only in the northern part of the State. Com- mon but scattered in Tioga and adjoining ccunties. HABITAT — Usually found on rich wooded slopes and on the borders of lakes, swamps, and streams; also scattered through the forests of other hardwoods and occasionally through coniferous forests. IMPORTANCE OF THE SPECIES— This species is commercially of little importance in Pennsylvania on account of its limited distribution. It is not of sufficient importance to justify its artificial propagation, but wherever it occurs naturally it should be protected so as to insure an abundant future growth. The wood is sufficiently prized to justify its conservative utilization, and also its protection, where nature produces it gratuitously. PLATE XLIII. PAPER BIRCH. 1. Flowering branch with immature leaves, (s) staminate flowers, (p) pistillate flowers, x J. 2. Branch with mature leaves, fruiting strobiles, and partly developed staminate aments, x i. 3. A winged seed, enlarged. 4. A strobile scale, enlarged. 6. A winter branch with 3 partly developed terminal staminate aments, x \. 6. Section of a lateral winter spur-branch, enlarged. 7. Section of a terminal winter branch, enlarged. PLATE XLIV. YELLOW BIRCH. 1. Flowering branch with (s) staminate flowers, and (p) pistillate flowers, x J. 2. Branch with mature leaves and four fruiting strobiles, x J. 3. A winged seed, enlarged. 4. A strobile scale, enlarged. 5. Winter branch with partly developed terminal staminate ameuts. x J. 6. Section of a lateral winter twig, enlarged. 7. Section of a terminal winter twig, enlarged. 115 YELLOW BIRCH. Betula lutea, Michaux. FORM — A large tree usually attaining a height of 00-80 ft. with a diameter of 2-3 ft., hut may reach a maximum height of 100 ft. with a diameter of 3-4J feet. Trunk in the open usually short, branching near the base; its long slender branches forming a wide open rather hemispherical crown, in close stands often rather free from lateral branches. BARK— Close and furrowed or peeling off in thin yellow film-like papery scales. Varies with the age and location of the tree. On young trunks and branches rather close, shining, ' yellow but soon forming a ragged fringe, later peeling off into thin, yellow, film-like, papery layers. On old trunks it finally becomes reddish-brown and roughened with fissures. The ragged bark is often pulled off and used by campers to start fires in wet weather. See Fig. 68. TWIGS — At first green and hairy, later brown and smooth, finally dull silvery-gray. Terminal twigs long and slender; lateral short nnd stout; usually covered with elongated horizontal lenticels which in time unite to form a long horizontal line. BUDS— Similar to those of the Black Birch, but sometimes slightly more downy. See page 118. LEAVES — Alternate, simple, occur singly or In pairs but never opposite, 3-4 inches long, ovate, wedge-shaped or heart-shaped at base, doubly serrate on margin, acute at apex, dull green above, yellowish-green below. LEAF-SCARS — Similar to those of the Black Birch in particular, and all of the other Birches in general. FLOWERS — Appear about April before the leaves. Staminate and pistillate separate, but usually on the same branch. Staminate are formed in the fall, remaining over winter as aments about 1 of an inch long which elongate to about 3 inches in spring. Pistillate about s of an inch long, with acute scales which are light red and hairy above, and green below. FRUIT — An erect, usually very short-stalke-I strobile, about 1-15 inches long, ovate in out- line, consisting of numerous 3-lobed scales fastened to a central axis and bearing small winged nuts with rather narrow wings. WOOD — Diffuse-porous; rays indistinct; heavy, hard, strong, compact, not durable when in coutnct with the soil. Heart-wood light brown, tinged with red; sap-wood pale in color. Weighs 40.84 pounds per cubic foot. Used for furniture, flooring, interior finish, boxes, certain veneers and fuel. DISTINGUISHING CHARACTERISTICS — The Yellow Birch, also known as Silver and Gray Birch, can readily be du-tinguished from the other Birches of Pennsylvania by its yellow bark which peels off into thin, film-like, papery scales. Its method of peeling the bark resembles that of the Paper Birch and the Red Birch, but it does not have the white color of the former nor the reddish to greenish-brown color of the latter. The loose, film-like, papery scales of the Red Birch are smaller than those of the Yellow Birch and the strobiles of the former are slender-stalked while those of the latter are usually sessile or very short-stalked. RANGE — Newfoundland, south to Pennsylvania, and along the mountains to North Carolina and Tennessee, west to Minnesota. DISTRIBUTION IN PENNSYLVANIA— Found locally throughout the State but most common in the Alleghenies. Rare or absent in the southeastern and southwestern parts. HABITAT — Common on moist rich uplands, borders of streams, and in swamps. IMPORTANCE OF THE SPECIES— The Yellow Birch is one of the largest deciduous trees of northeastern America. Until recently the value of its wood was not fully appreciated, but today it holds a fair position on the lumber market and in the future it will no doubt attain a still better position. It has been classed as one of the most artistic, reliable, and versatile of the hardwoods of this country. With all its good qualities, it has superior associates and consequently cannot be recommended for forestry purposes except on the farmer's woodlot where fuel is especially desired and in such other places where it comes up naturally and other more desired species will not grow to advantage 116 RED BIRCH. Betula nigra, Linnaeus. FORM — A medium-sii.ed tree usually attaining a height of 30-50 ft. with a diameter of 1-2 ft., but may reach a height of 100 ft. witii a diameter of 5 feet. Trunk usually short and divided near the base into a few slightly diverging limbs. Crown rather narrow, oblong, and irregular. BARE — Varies with the age of the tree and its location on the trunk. On lower part of old trunks dark reddish-brown and roughened by fissures which separate irregular scales. On younger trunks and upper portion of older ones peels off into thin, film-like, papery scales which are reddish-brown to greenish-brown in color and persist for a few years during which time they form a ragged fringe and expose the light red and close bark underneath. See Fig. 65. TWIGS — Slender, at first hairy and greenish, later smooth, reddish-brown, covered by pale horizontally-elongated lenticels. BUDS — Alternate, ovate, sharp-pointed, shining, smooth or slightly hairy, covered with1 usually 3-7 chestnut-brown overlapping scales. LEAVES — Alternate, simple, broadly ovate, 15-3 inches long, wedge-shaped at base, acute at apex, doubly-serrate on margin, deep green above, pale yellowish-green below. LEAF-SCARS— Similar to those of the Black Birch. See page 118. FLOWERS — Appear about April before the leaves. Staminate and pistillate separate, but usually on the same branch. Staminate formed in the fall, remaining over winter as aments about 1 of an inch long, usually in clusters of three, which elongate to about 2-3 inches the following spring. Pistillate about $ of an inch long, developing in spring from buds situate below the starainate flowers. FRUIT — An erect, slender-stalked, pubescent, cylindrical strobile, 1-15 inches long, consisting of numerous 3-lobed pubescent scales fastened to central axis and bearing small, hairy, winged nuts. Terminal lobe of the scales is larger than the laterals. WOOD — Diffuse-porous; rays indistinct; light, soft, strong, with light-brown heartwood and pale thin sapwood. Weighs 35.91 pounds per cubic foot. Used in the manufacture of furniture, slack-cooperage, fruit and vegetable baskets, wooden ware, and turnery. DISTINGUISHING CHARACTERISTICS— The Red Birch, also known as the River Birch, can be recognized by its reddish -brown to cinnamon-red bark which peels off into film-like papery scales. The layers are smaller and less ragged than those of the Yellow Birch which has a decidedly yellow or silvery -yellow colored bark. The Black Birch has a closer bark which does not peel off and the other species of Pennsylvania have a white bark. The River Birch Is usually found along streams or in other wet locations which may also aid in dis- tinguishing It. RANGE — Massachusetts south to Florida, west to Minnesota, Kansas and Texas. DISTRIBUTION IN PENNSYLVANIA— Found throughout the State along the banks of the principal rivers and their chief tributaries, but rare in the western part. HABITAT — Prefers the banks of streams, lakes, pools, and swamps. Occasionally found upon drier locations. It is called River Birch because it is usually found along the banks of rivers or other locations having similar moisture conditions. IMPORTANCE OF THE SPECIES — The Red Birch is of little commercial Importance in Pennsyl- vania as a lumber species on account of the relatively small size which it attains, the softness of its wood, and the absence of figure and attractive color in the wood as well as its limited distribution. It is esreiitially a southern species reaching its optimum development in North Carolina and adjoining states. While it is of little commercial importance it may be of economic importance in such situations where moistuie-loving trees are required to bind soil, as along streams, or where it is desirable to establish stands in extremely swampy locations. It is attract Ive as an ornamental tree. PLATE XLV. RED BIRCH. 1. Flowering branch with (s) staminate flowers, (p) pistillate flowers, x J. 2. Branch with mature leaves aud two fruiting strobiles, x J. 3. A winged seed, enlarged. 4. A strobile scale, enlarged. 5. A winter branch with three partly developed terminal staminate aments, x 6. Section of a winter branch, enlarged. PLATE XLVI. GRAY BIRCH. 1. Flowering branch with immature leaves (s) staminate flowers, (p) pistillate flowers, x i. 2. Branch with mature leaves and fruiting strobiles, x J. 3. A winged seed, enlarged. 4. A strobile scale, enlarged. 5. A winter branch with a partly developed terminal staminate ament, x J. 6. Section of a winter twig, enlarged. 117 GRAY BIRCH. Betula populifolia, Marshall. FORM — A small tr«e usually occurring in clumps and attaining a height of 20-30 ft. with a diameter of 9 inches, but may reach a height of 45 ft. and a diameter of 18 inches. Trunk slender, often inclined, continuous, and covered with ascending lateral branches with drooping ends which form a narrow pyramidal, rather open, and pointed crown. BARK — Dull white, close, smooth, not peeling off into thin film-like layers but covered with triangular black spots below the insertion of the lateral branches. On old trunks black and roughened with fissures. Inner bark orange-yellow. See Figs. 64 and 69. TWIGS — Slender, greenish to brown, roughened by warty exudations and by raised, pale, and horizontally-elongated lenticels; later smooth and dull white. BUDS — Alternate, 2-ranked, ovate, 1/5 of an inch long, sharp -pointed, divergent, covered with 3-4 visible smooth, slightly resinous, brown bud-scales with downy margins. LEAVES — Alternate, simple, triangular, ovate, 2J-3 inches long, lj-2 inches wide, wedge- shaped at base, decidedly serrate on margin, with long-toothed apex and long, slender petioles which cause the leaves to quiver when stimulated by a slight breeze only. LEAF-SCARS— See "Leaf-Scars" under Black Birch, page 118. FLOWERS— Appear about April before the leaves. Staminate in solitary or occasionally paired aments which are about 11-15 inches long and 1 of an Inch wide during the winter, but develop in spring to a length of 2-4 inches. Pistillate cylindrical, slender, about J of an inch long and stalked. FRUIT — A slender, cylindrical, stalked strobile about I of an inch long and obtuse at the apex. Scales small an3 downy; their lateral lobes broad and recurving, while the terminal one is rather straight and narrow. Seeds small, oval,* and winged. Wings broader than the seed. WOOD — Diffuse-porous; rays inconspicuous; light, soft, not strong, not durable; heartwood light brown; sapwood light. Weighs 35.90 pounds per cubic foot. Used for fuel, and in the manufacture of paper pulp, spools, shoe pegs, and hoops for barrels. DISTINGUISHING CHARACTERISTICS — The Gray Birch, also known as Oldfleld, White, Poverty, or Poplar Birch, can be distinguished from all the other Birches of Pennsylvania, except the native Paper Birch, and the commonly introduced European White Birch, by its white bark which Is never renewed when once removed. The bark is close, dull white, and marked with black triangular blotches just below the insertion of the lateral branches, and does not peel off in thin paper-like layers like that of the Birch. The Gray Birch is usually a small tree with a rather continuous trunk and frequently occurs in clumps. The twigs ' of the Gray Birch are also rougher than the Paper Birch and its leaves are long- acuminate, while those of the Paper Birch are ovate. RANGE — Nova Scotia south to Delaware and southern Pennsylvania, west to the southern shores of Lake Ontario. DISTRIBUTION IN PENNSYLVANIA — Locally in the mountainous portion. Common in Monroe, Schuylkill and Pike counties. Abundant along streams in northern part of the State. A few specimens found on top of South Mountains in Franklin county near Mason and Dixon line, and on Tussey mountain in Huntingdon county. HABITAT — Usually occurs on moist soil along streams, ponds, and lakes; also grows on hillsides and occasionally on rocky mountain tops. IMPORTANCE OF THE SPECIES — This species is of little commercial value on account of the small size which it attains due to its short life. The existing stands should, however, be conservatively utilized. It cannot be recommended for forest planting, but Is an extremely attractive tree for ornamental purposes. 118 BLACK BIRCH. Betula lenta, Linnaeus. FORM— This tree usually attains a height of 50-60 ft. with a diameter of 1-3 ft., but may reach a height of 80 ft. with a diametei of 5 feet. Trunk rather continuous, sometimes subdivided, bearing long, slender, lateral branches which are ascending on young trees forming a narrow conical crown, or often pendulous on old specimens forming a wide spreading crown. BARK — On old trunks (Fig. 71) distinctly black, broken into large, thick, irregular plates which are smooth on the surface; on younger parts of the trees (Fig. 70) smooth, shining, very close fitting, reddish-brown, with sweet wintergreen taste and covered with horizontally- elongated lenticels. TWIGS — During the first summer light green and hairy, later becoming reddish-brown, smooth, shining, with pronounced wintergreen-like flavor. Terminal twigs slender and elongated, while lateral spurs are numerous, stout, and short. BUDS— Alternate, about 1 of an inch long, conical, sharp-pointed, shining, covered with reddish -brown overlapping scales with downy margins. Three bud-scales usually visible on buds of terminal shoot and fiom 5-8 on lateral spur shoots. LEAVES— Alternate, simple, ovate, usually heart-shaped at base, serrate on magrin, long- pointed at apex, dark green above, pale green below, 25-5 Inches long, 11-3 inches wide. LEAF-SCARS — Alternate, small, semi-oval in outline, containing 3 rather small, equidistant bundle-scars. FLOWERS— Appear about April before the leaves. Staminate formed in fall, remaining over winter as aments about I of an inch long, in clusters of usually three, which elongate to about 3 or 4 inches the following spring. Pistillate about i-J of an inch long, slender, and pale green. FRUIT — A strobile about 1J-2 inches long, sessile, smooth, erect, with smooth 8-lobed scales and small winged nutlets. Lobes of the scales are about equal in length but the terminal is narrower and sharper-pointed. WOOD — Diffuse-porous; rays indistinct; heavy, strong, hard, dark brown, with thin yellowish sap wood. Weighs 47.47 Ibs. per cubic foot. Used for furniture, often in imitation of Mahogany, and for interior finish; also substituted for Cherry and occasionally for Hickory. Trees cut in spring at about the time the buds open, bleed more than any other species, but the sap contains less saccharine material than that of the Maples. DISTINGUISHING CHARACTERISTICS— The Black Birch, also known as Sweet Birch, and Cherry Birch, can be distinguished from all the other species of Birch in Pennsylvania by its close, blackish, cherry-like bark which does not peel off into film-like layers. It closely resembles the Yellow Birch but the latter has yellow bark which peels off into thin film- like layers. The twigs have a distinctly wintergreen-like flavor which is absent in the other species. The scales of the fruit of the Black Birch are smooth about equally lobed while those of the Yellow Birch are hairy and irregularly lobed. RANGE — Newfoundland to Florida, west to Ontario, Illinois and Tennessee. DISTRIBUTION IN PENNSYLVANIA— Common throughout the State, and locally frequent. HABITAT — Usually found in rich soil and on dry slopes but also common on rocky mountain slopes and tops. Common on the rocky ridges of the South Mountains in Pennsylvania. IMPORTANCE OF THE SPECIES— The Birches, next to the Hickories, furnish the best fuel wood of all the native species of Pennsylvania. The wood of Black Birch ranks high as a fuel wood and is becoming more important in the manufacture of furniture, especially as a substitute for Mahogany and Cherry. This tree also yields an oil sold as a substitute for wintergreen. While this species has many good 'qualities still it is. a slow grower and when quite young is subject to the attack of fungi, which materially decrease the technical value of the wood. It is not of sufficient importance to be regenerated artificially but should be developed where it appears naturally. This species occurs naturally upon extremely rocky ridges and may be a very desirable species in establishing protection forests upon steep . mountain slopes and rocky mountain tops. PLATE XLVII. BLACK BIRCH. 1. Flowering branch with (s) staminate flowers, (p) pistillate flowers, x J. 2. Branch with mature leaves and three fruiting strobiles, x i. 3. A winged seed, enlarged. 4. A strobile scale, enlarged. 5. Winter branch with partly developed terminal staminate aments, x J. 6. Section of a winter twig, enlarged. PLATE XLVIII. AMERICAN HOP HORNBEAM. 1. Flowering branch with immature leaves, (s) staminate flowers, (p) pistillate flowers, x 2. Branch with mature leaves and hop-like fruit clusters, x J. 3. A seed with inclosing membrane, slightly enlarged. 4. A seed with part of inclosing membrane removed, slightly enlarged. 5. A winter branch with partly developed terminal staminate aments, x 1. 6. Section of winter twig, enlarged. 119 AMERICAN HOP HORNBEAM. Ostrya virginiana, (Miller) K. Koch. GENUS DESCRIPTION — This genus comprises about 4 species which are widely distributed in the northern hemisphere. Two species are native to America and 2 to the eastern hemisphere. One of the American species is more limited in its distribution than any other known tree, being found only in the Grand Canon of the Colorado River in Arizona while the other American species is rather widely distributed over the eastern part of the country., FORM— Usually attains a height of 20-30 ft. with a diameter of li ft., but may reach a height of 60 ft. with a diameter of 2 feet. Crown high, open, and very broad, formed by widely spreading often drooping branches with ascending branchlets. BARK — Grayish-brown, thin, roughened by loose flattish scales which are loose at the ends. See Fig. 54. TWIGS — Slender, tough, dark reddish-brown, zigzag, at first hairy and green, later smooth, lustrous, dark brown. BUDS — Alternate, ax'llary; terminal bud absent; ovate, 1 of an inch long, sharp-pointed, distinctly divergent, slightly pubescent, smooth, gummy, covered by about 8 visible, longi- tudinally-striated, 4-ranked scales which increase in size from the base towards the apex. LEAVES — Alternate, simple, ovate-oblong, acute at apex, doubly-serrate on margin, rounded or heart-shaped or wedge-shaped at base, 3-5 inches long; dull yellowish-green above, paler green below. LEAF-SCARS— Alternate, small, flattened, 2-ranked, with usually 3 small bundle-scars. FLOWERS — Appear about April with the leaves. Staminate aments appear about midsummer usually in about 3s at the end of the twigs and persist during the winter; they are stiff, hairy, about ! of an inch long, becoming about 2 inches long in spring and covered with reddish-brown scales. Pistillate flowers appear in erect aments, each one inclosed in a hairy bladder-like bract. FRUIT — A small Hat nutlet, inclosed in an inflated bladder-like bract which is covered at the base with long hairs irritating to the skin. Bracts arranged in hop-like, pendant clusters which fall during winter and leave the persisting naked stalk. WOOD — Diffuse-porous; rays indistinct; strong, hard, durable, light brown to white. Weighs about 51 Ibs. per cubic foot. Used for fence posts, tool handles, and mallets. DISTINGUISHING CHARACTERISTICS— The American Hop Hornbeam, also known as Ironwood, Leverwood, and Deerwood, can readily be recognized by its thin grayish-brown bark which peels off into narrow flat scales often loose at both ends and only attached in the middle. The hop-like clusters of sac-like fruit are also peculiar, which usually fall before winter but the stalks to which they are attached often persist. la winter the very slender interlacing branches, the staminate catkins usually occurring in 3s at the end of the twigs, the small 2-ranked leaf- scars with 3 bundle sea rt, and the small reddish-brown buds with 4-ranked scales are charac- teristic. The autumnal color of the leaves is yellow while that of the closely related American Hornbeam is brilliant orange to deep scarlet. The hardness of the wood is also distinctive. The wood is about 30 per cent, stronger than White Oak. RANGE — Cape Breton Islands to Florida, west to Minnesota and Texas. DISTRIBUTION IN PENNSYLVANIA— Found locally throughout the State but nowhere abundant. Usually mixed with other species. Rarely conspicuous In the composition of the forest. HABITAT — Prefers dry gravelly slopes and ridges, occasionally moist situations. Usually seeks cool and shaded situations, and Is never found in pure stands or groups, but occurs singly in mixture, often as an undergrowth of Oak, Maple, Chestnut, and other forest species common to its range. IMPORTANCE OF THE SPECIES — The American Hop Hornbeam produces a valuable wood and grows rapidly, but its solitary habits as well as its silvicultural characteristics and the relatively small size which it attains, do not recommend it for forestry purposes. It is well adapted for planting in lawns and parks. 120 AMERICAN HORNBEAM. Carpinus caroliniana, Walter. GENUS DESCRIPTION — This genus comprises about 12 species which are confined to the northern hemisphere. Only 1 species is found in America. A few of the other species ar6 native to Europe, while most are found in northern and central Asia. FORM— A small tree or shrub usually attaining a height of 10-30 ft, with a diameter of 8-12 fnches, but may reach a height of 40 ft. with a diameter of 2 feet. Trunk usually short, fluted, and bearing a wide-spreading usually round-topped crown with tough ascending branches often pendulous towards the end. BARK — Vertically corrugated, smooth, thin, close-fitting, bluish-gray tinged with brown. See Fig. 93. TWIGS — Slender, ut first silky, hairy, and green, later smooth, shining, reddish to orange; covered with scattered pale lenticels. BUDS— Alternate, axilliary; terminal bud absent; ovate, pointed, i of an inch long, reddish- brown, covered with 8-12 visible 4-ranked bud-scales. Bud-scales increase in size from the base towards the apex, are longitudinally -striate and often ciliate on margins. LEAVES — Alternate, simple, ovate-oblong, acute at apex, doubly-serrate on margin, rounded or wedge-shaped at basn, 2-4 inches long, deep green above, paler below. LEAF-SCABS— Alternate, small, elevated, elliptical, with generally 3 inconspicuous bundle- scars. FLOWERS — Appear about April with the leaves. Staminate start to develop In fall and remain over winter in the form of buds which resemble the leaf -buds, only are larger. When fully developed they are drooping aments about U inches long. Pistillate appear as aments, about | of an inch long, with bright scarlet stylps. FRUIT— A small corrugated nut about $ of an inch long inclosed by a leaf-like, 3-lobed bract which is usually serrate only on one margin of middle lobe. WOOD — Diffuse-porous; rays conspicuous and broad along short radii; heavy, hard, strong, light brown with broad sapwood. Weighs about 45 Ibs. per cubic foot. Used for fuel, tool aandles, and levers. DISTINGUISHING CHARACTERISTICS — The American Hornbeam, also known as the Blue Beech, Ironwood, and Water Beech, may be distinguished by its vertical, corrugated, bluish-gray, smooth bark. The leaf-like 3-lobed bract with its corrugated nut is also characteristic. The staminate catkins remain in the bud during the winter, while those of the American Hop Horn- beam are developed in autumn. It resembles the American Beech, but can readily be distinguished from it by its corrugated bark and the absence of the long, slender, conical, and sharp- pointed buds so characteristic of the Beech. The buds are usually downy at the apex while those of the American Hop Hornbeam are smooth and slightly gummy within. The autumnal color of the leaves is brilliant orange to deep scarlet. RANGE — Nova Scotia to Florida, west to Minnesota and Texas. DISTRIBUTION IN PENNSYLVANIA— Found locally throughout the State. Sometimes rather abundant and conspicuous in wet habitats. Common in Franklin, Adams, Northampton, Fulton, Centre, Huntingdon, Tioga, and Union counties. HABITAT — Usually found in swamps and on the border of streams, whence its name Water Beech. In Pennsylvania it Is found in the valleys, along streams, in swamps, and In similar habitats on the mountain flats and on moist fertile mountain slopes. IMPORTANCE OF THE SPECIES — This species on account of its small size, sloy its alternate compound leaves with 13-17 sessile leaflets which are conspicuously toothed. The flat-topped cymes of white flowers measuring about 3-4 inches across, and the bright red fruit about the size of a pea and arranged in flat-topped clusters are characteristic. The stout grayish to reddibh-brown twig with conspicuous pale lenticels and the purplish-red, sharp pointed, somewhat gummy and usually smooth alternate buds are also characteristic. RANGE— Newfoundland westward to Manitoba and Iowa, southward in the mountains to North Carolina. DISTRIBUTION IN PENNSYLVANIA— Limited to the mountainous region of the State. A line drawn from the western part of Tioga county south to Somerset cpunty and thence north- east to Monroe county will include the general distribution of this species. HABITAT — Prefers moist or rocky hillsides. Often found on the border of streams and locally common on rocky hillsides. IMPORTANCE OF THE SPECIES — This species is of no commercial importance. It rarely exceeds a height of £0-15 ft. with a diameter if 12-15 inches. It is rather attractive and de- serves to be planted for ornamental purposes. Its attractive ornamental features are its form, broad cyme-like clusters of white flowers, and its bright red clusters of fruit which ripen in autumn. 174 SHAD BUSH. Amelanchier canadensis, (Linnaeus) Mendicus. GENUS DESCRIPTION — The genus Amelanchier comprises about 30 species of small trees and shrubs found mainly in the temperate portion of the northern hemisphere. About 23 species are found in North America, 6 of which attain tree-size. Four species are native to Pennsylvania, only 1 of which attains tree-size. FORM — A small tree usually 10-25 ft. in height with a diameter of 6-12 inches but may reach a height of 40 ft. with a diameter of 20 inches. Trunk usually straight, slender, with little taper, bearing a shallow, and narrow crown appearing very dense on account of abundant fine sprays of branchlets. BARK — Rather smooth on young and old specimens. On older specimens there is a tendency to roughen through shalJow, longitudinal, sometimes diagonal fissures which are rather dark and separate broad, lighter, and smooth ridges becoming scaly near the base. TWIGS — Slender, somewhat zigzag, bright green to purplish-brown, smooth or often overlaid with a grajish film-like coating which peels off; covered with a few, pale, scattered lenticels; pith small, greenish, angular. BUDS — Alternate, usually 2-ranked, slender, conical, 1-1 of an inch long, 3-4 times as long as broad, sharp-pointed, greenish-brown often tinged with purple, sometimes smooth often hairy towards apex and along bud-scales. Terminal buds longer than lateral which are usually appiessed close to twig, sometimes remaining very small. Bud-scales largest near base, often 3-nerved, darker and finely hairy along margin. LEAVES — Alternate, simple, ovate to ovate-oblong, 3-4 inches long, sharp-pointed at apex, round or heart-shaped at base, finely and sharply serrate on margin, at first finely hairy, later smooth, dark green above, paler below. LEAF-SCARS — Alternate, usually 2-ranked, small, inconspicuous, rather linear with projection at bundle-scars which an> large and 3 in number. FLOWERS — Appear about April when leaves are just starting to develop; large, white, per- fect, stalked, arranged in drooping racemes 3-5 inches long. FRUIT — Matures in June or July. Berry-like in racemes, reddish-purple, with a bloom when fully ripe, about i of an inch in diameter, sweet, and containing small seeds. WOOD — Dilf use-porous; rays numerous, indistinct, dark brown often touched with red; heavy, hard, strong, checks uud warps easily, very susceptible to high polish. Weighs 48.85 Ibs. per cubic foot. Used to a limited extent, mainly in turnery. DISTINGUISHING CHARACTERISTICS — The Shad Bush, also known as Service Berry, June Berry, and Sarvice, can readily be distinguished in winter by its smooth grayish often black- streaked bark and its long, slender, conical, sharp-pointed, greenish-brown to purplish buds which are often finely hairy towards the apex and along the margin of the scales. The buds, in form and to some extent in size, resemble the Beech but the buds of the Beech are usually larger, clear reddish-brown in color and have from 10-20 scales arranged in 4 rows. The twigs of the Beech are shining reddish-brown while those of the Shad Bush are usually bright green to grayish or purplish-brown. The stipule scars are absent on the Shad Bush while they nearly encircle the twig of the Beech. The large white flowers arranged in drooping racemes 3-5 inches long are alno characteristic. The leaves and the fruit will aid in distinguishing it in summer. RANGE — Newfoundland and Ontario, southward to Florida, westward to Kansas and Louisiana. DISTRIBUTION IN PENNSYLVANIA — Found in every portion of the State. Most abundant among the mountain ranges. HABITAT — Occurs solitary or occasionally In clumps. Prefers open situations and moist soil, but also grows on sandy rather sterile soil. Common along the border of forests, banks of streams, forest roads, and cliffs. Small specimens common in tbe understory of our hardwood forests. IMPORTANCE OF THE SPECIES— This species is of little commercial Importance because its wood is rarely used. It will always be a minor species not on account of the inferiority of its wood but on account of its small size and limited and scattered distribution. The wood is actually stronger end stiffer than White Oak. Its conspicuous white flowers in early spring before the leaves are out justify its retention in the forest, especially where it does not inter- fere with the growth of other more valuable trees. The berries are excellent food for birds, beasts, and man. PLATE XCII. SHAD BUSH. 1. A flowering branch, x 1. 2. Longitudinal section of a flower, enlarged. 3. A fruiting branch with mature leaves, X \. 4. Section of a fruit, enlarged. 5. A winter twig, natural size. 6. Section of a winter twig, enlarged. PLATE XCIII. BUTTONWOOD. 1. A flowering branch, x i. 2. A head of flowers with most of the flowers removed, 3. A staminate flower, enlarged. 4. A pistillate flower, enlarged. 5. A fruiting branch with mature leaves, x 1. 6. An achene, enlarged. 7. A winter twig with two heads of fruit, x J. 8. Section of a twig showing a subpetiolar bud, x 1. 9. Section of a twig showing a stipule, natural size. 10. Section of a winter twig, enlarged. x 4. 175 BUTTONWOOD. Platanus occidentalis, Linnaeus. FAMILY AND GENUS DESCRIPTION — The Plane Tree family, Platanaceae, comprises only 1 genus, Plutanus, with about 7 species, 3 of which are native to the United States and 1 to Pennsylvania. In addition to the 1 species native to this State, the Old World Plane Tree (Platanus orientalis L.) is very commonly planted as a shade tree in the eastern states. FORM — Usually attains a height of 70-125 ft., but may reach a height of 140-170 ft. with a diameter of 10-11 feet. It is the most massive of the deciduous trees of North America. Trunk usually branches near the base into heavy sub-trunks, vvhich sub-divide and form a very deep, wide-spreading, rather open, and irregular crown. BARK — On old trunks rather thick, rigid, roughened by shallow fissures separating broad ridges which peel off into thin dark brown scales. On young trunks and upper parts of old ones it peels off spontaneously into large thin plates exposing a whitish, yellowish, or a greenish inner bark. This mottled inner bark is characteristic, but rarely found near the ground. See Fig. 57. TWIGS— Rather stout, zigzag, at first green and pubescent, later brownish to gray and smooth, decurrently ridged, enlarged at the nodes, marked by numerous, small, pale lenticels, encircled by stipule-scars. Pith wide and white. BUDS — Alternate; terminal bud absent; sub-petiolar, surrounded by base of leaf -stalk or leaf- scars, i-J of an inch long, conical, dull-pointed, very divergent from section of branch above end slightly from section below, covered with 3 scales, the outer one of which is smooth, shining, reddish-brown, the middle green and gummy, and the inner pubescent. LEAVES — Alternate, simple, broadly ovate, 3-5-lobed, toothed on margin, 4-10 inches across, bright green above, pale green and white woolly below. Petioles about 2 inches long, round, with enlarged hollow bases. Stipules 1J inches long, conspicuous, encircling twig. LEAF-SCARS — Alternate, 2-ranked, unequal in width, have a wavy outer margin, nearly encircle the buds at enlarged nodes of branches, fcrm an angle of about 60 degrees with the section of branch below, contain 5-10 bundle-scars which are arranged in a curved line and occur singly or in groups. FLOWERS— Appear in dense heads with the leaves in May. Staminate and pistillate flower heads occur on different stalks. Staminate are axillary and dark red; pistillate terminal, greenish and often tinged with red. FRUIT — Matures in October. Occurs solitary or rarely in 2s in brown heads about 1 inch in diameter suspended from a slender stalk. Heads often persist far into winter and are composed of many hairy achenes about I of an inch long. WOOD — Diffuse-porous; rays conspicuously broad; pores minute; hard, difficult to split, reddish-browr with light to jyellowish sapwood. Weighs 35.39 Ibs. per cubic foot. Used in the manufacture of furniture, interior furnishing, crates, tobacco boxes, and charcoal. DISTINGUISHING CHARACTERISTICS— The Buttonwood, also known as Buttonball, Syca- more, and Plane Tree, can readily be distinguished in summer by its massive form, its whitish, yellowish, or greenish bark of the upper branches which at times are covered with large, thin, dark brown scales of outer bark. The large leaves with their enlarged hollow- based petioles and the flowers in the form of neads, are also characteristic. In winter the massive form and whitewashed appearance of the upper branches is distinctive. The smooth, reddish, sub-petiolar buds covered by a single exposed scale and surrounded by a leaf-scar with 5-10 bundle-scars will prevent one from confusing it with any other of our native species. The persistent fruit which usually occurs solitary is readily distinguished from the oriental species which bears its fruit in clusters of 2-4. RANGE — Maine and Ontario south to Florida, Avest to Minnesota, Nebraska and Texas. DISTRIBUTION IN PENNSYLVANIA— Common along streams, especially in the eastern, southern, western and central parts of the State. HABITAT — Prefers racist, fertile soil, but will grow in rather dry soil. Best development In the moist valleys of the Ohio and Mississippi rivers. IMPORTANCE OF THE SPECIES— The wood of this species is annually becoming of more commercial importance and hence it should be planted at least to a limited extent. It may be grown from cuttings or from seed. It is planted sparingly for ornamental purposes but the Oriental Sycamore seems to be preferred eince it is more attractive and less subject to fungous diseases. 176 THE PULSE FAMILY— LEGUMINOSAE. This is a very large family and contains many well-known trees, shrubs, and herbaceous plants. It comprises about 460 genera with 7,350 species of which number more than 100 genera with about 1,400 species are native to North America. The flora of Pennsylvania com- prises about 32 genera with approximately 90 species but only 4 spe- cies belonging to 4 different genera can be classified as trees. Some authors separate the members of this family into 3 distinct families known as: (1) The Mimosa family, Mimosaceae, (2) The Senna fam- ily, Caesalpiniaceae, and (3) The Pea family, Fabaceae. Many domestic and foreign plants which belong to this family are of considerable economic importance. Some of our native trees pro- duce very heavy, hard, and strong wood. They possess additional merits in that they grow rapidly and are well adapted to artificial propagation. Some of them, in particular, the Common Locust, are subject to the attack of destructive insects and fungi. Some of the shrub members of this family are among the most attractive that one can find for ornamental planting. The herbaceous members com- prise some of the commonest and most valuable food and forage plants of the world, such as the peas, beans, clover, and the common peanut. Among the valuable products *which some of the foreign members of this family produce one can mention Senna and Log- wood. Senna is prized on account of its laxative properties and is derived from the leaves of a few African species of Cassia. Log- wood, the most important of vegetable dyes, is derived from the heartwood of the trunk and roots of a tree growing in the West Indies and Central America. Indigo, one of our important and widely used dyes, is also obtained from a member of this family. The well-known Sensitive Plant (Mimosa pudica L.) so common in our greenhouses and a mere weed in the tropics is one of the most widely known and interesting representatives of this family. In addition they comprise a great number of plants which are important on account of the medi- cinal properties derived from them. Probably one of the greatest values which we can attach to some of the members of this family is the means which they have at their command for restoring nitrogen to barren land. If one examines the roots of clover, alfalfa, soy bean, or the Common Locust he may find little swellings or enlarge- ments upon them known as root tubercles. These swellings are caused by bacteria which possess the power of taking free nitrogen from the air and by means of complicated chemical changes passing it to members of this family. As a result these plants can be grown upon soils very deficient in nitrates. In addition they will return sufficient nitrogen to the soil so that companion or subsequent crops will thrive which would have barely existed without the nitrogen. The Common Locust often thrives on old abandoned mud-dams found about ore mines while other more aggressive species fail even to es- tablish themselves. The members of this family are distinctly characterized by their fruit which matures in one season and usually resembles ordinary garden beans or peas. The fruit of some of the trees found in the western part of North America varies more or less from the typical bean-like fruit pod. The flowers of our native trees may be irregular in form, i. e. pea-like or bean-like, as in the Common Locust and Ked- bud, or regular in form as in the Honey Locust and Kentucky Coffee Tree. The two native tree-species with irregular flowers have also perfect flowers, i. e. flowers with both the male (pollen producing) and female (seed producing) organs in the same flower while the other two native tree-species have regular but imperfect flowers, i. e. flowers with one sex so suppressed that only the other sex remains in each flower. Whenever the male and female flowers, also known as staminate and pistillate flowers respectively, occur separately, they may be found on the same branch, or on the same tree, or on different trees. The leaves of nearly all the tree members of this family are alternate and compound, but a few such as our native Eedbud have simple leaves. Some species as our Common Locust are normally only once compound, others as the Honey Locust may be once or twice compound, while still others, as the Kentucky Coffee Tree, may be normally twice compound. SUMMER KEY TO THE GENERA. Page. 1. Leaves simple; iwijr.3 slender and unarmed, Cercis 180 1. Leaves compound; twigs stout or armed with spines or thorns, 2 2. Twigs very stout and clumsy but not armed with spines or thorns; fruit-pods woody; leaves twice compound, from 1-3 ft. long Gymnocladus 178 2. Twigs relatively slender and armed with spines or thorns; fruit-pods leathery; leaves usually cnce or sometimes twice compound, rarely over 1 ft. long, 3 3. Flowers greenish, regular or nearly so, imperfect, in axillary spikes; leaves once or twice compound, even-pinnate; twigs, branches, and often trunks with long branched thorns Gleditsia 179 3. Flowers whitish, irregular, perfect in drooping racemes; leaves usually once com- pound, odd-pinnate; twigs often with two short spines at nodes Robinia 181 WINTER KEY TO THE GENERA. 1. Twigs, branches, anne which reaches tree-size. Two other shrub species, Sheep Laurel (Kalmia angustifolia L.) 'and Swamp Laurel (Kalmia polifolia Wang.), are also native to this State. The genus is named after Peter Kalm, a Swedish naturalist, who traveled in North America during the middle of the 18th century. FORM — In Pennsylvania usually a shrub 5-10 ft. in height with a stout stem which is usually forked, often inclined and bearing divergent branches which form a round compact head. In the South it reaches a height of 30-40 ft. with a diameter of 20 inches. BARK — Very thin, reddish-brown, furrowed, peels off into long, narrow, thin scales ex- posing cinnamon-red inner bark. TWIGS — At first reddish-green covered with viscid hairs, later becoming decidedly green, and finally brown. Rather smooth except where roughened by leaf-scars and bud-scale scars. BUDS — Alternate, ovate, sharp-pointed, greenish in color. Leaf-buds are formed early and appear below the clustered flower-buds. Flower-buds are covered by numerous, downy and over- lapping green scales which arc coated with glandular hairs and enlarge with the developing shoot in spring. LEAVES — Alternate, sometimes paired, simple, oblong, wedge-shaped at base, entire- margined, acute at apex sometimes tipped with bristle point, 3-4 inches long, about i of an inch wide. Mature leaves are thick, leathery, dark green, glossy above, yellowish-green below, and persist for two seasons. LEAF-SCARS — Large, imbedded in twig, with a cluster of bundle-scars. FLOWERS — Emerge from flower buds which begin to expand hi early spring and open about May or June. Flowers are borne on red or groen scurfy stalks and arranged in dense many- flowered corymbs which have a diameter of about 4 inches. Calyx is divided into five parts. Corolla is white to rose-colored and viscid pubescent. FRUIT — Matures about September. It is a many -seeded woody capsule, roundish in outline but slightly five-lobed and covered with viscid hairs. Both style and calyx persist. Each capsule produces many seeds. WOOD — Diffuse-porous; heavy, hard, strong, rather brittle. Heartwood reddish-brown, sapwood lighter colored. Weighs 44.62 Ibs. per cubic foot. Where it grows to a fair size it is an excellent wood for fuel. It is also used in manufacture of tool handles, penholders, bucket handles, turnery, and tobacco pipes. About 85,000 Ibs. of this wood are produced annually in North Carolina for pipes. DISTINGUISHING CHARACTERISTICS — The Mountain Laurel, also known as Kalmia and Calico-Bush, is one of our few broad-leaved species whose leaves persist over winter. It can be distinguished from all other species native to this State by its thick leathery leaves which are 3-4 inches long, persistent, decidedly glossy on upper surface and yellowish-green on lower surface. The Great Laurel or Rhododendron is also evergreen but its leaves and buds are much larger than those of the Mountain Laurel. The leaves of the Mountain Laurel are shorter, narrower, and sharper-pointed than tnose of the Rhododendron. RANGE — New Brunswick south generally along the mountains to Florida, west to Arkansas. DISTRIBUTION IN PENNSYLVANIA — Throughout the State. Most common In the moun- tainous parts, where it often forms almost impenetrable thickets. Very rare and local, or absent, in the extreme western part. HABITAT — Common along margins of swamps and as an understory in deciduous forests. Also found on hillsides and hilltops. Very common on rocky and round hilltops. IMPORTANCE OF THE SPECIES — The Mountain Laurel remains too small in this State to be of commercial importance on account of the wood which It produces. Next to Rhodo- dendron, it is the most attractive native shrub found in our flora. It is a favorite with lovers of the woods who admire not only Its blossoms, brt also its leaves and its habit of growth. 208 GREAT LAUREL. Rhododendron maximum, Linnaeus. GENUS DESCRIPTION — The name Rhododendron is of Greek origin and means Rose tree. It comprises about 100 species of shrubs and a few small trees in the northern hemisphere. About 10 species are native to North America and 1 to Pennsylvania. FORM — A shrub or small bushy tree. In this State Dually a shrub from 5-12 ft. in height, but in the mountains ot the South it may reach j," height of 35 feet. Stems often twisted, bearing contorted branches which form an irregular round head. BARK — Thin, reddish-brown, at first close, later peeling oft into thin scales. TWIGS — At first green and coated with rusty pubescence but become smooth during first winter, and gradually turn to bright red-brown. BUDS — Alternate; leaf-buds and flower-buds distinct. Leaf -buds usually axillary sometimes terminal, dark green, cone-shaped, form in midsummer. Flower-buds usually terminal, cone- shape, 1-15 inches long, covered by numerous, overlapping, green bracts. LEAVES — Alternate, simple, persistent, clustered at apex of branches, ovate to oblong, acute at apex, rounded to wedge-shaped at base, entire on margin, 4-11 inches long, 1J-2J inches wide, thick, leathery, smooth and dark green en upper surface, whitish on lower surface. LEAF-SCARS — Alternate, slightly raised, conspicuous, rounded at base, slightly depressed at top, with several bundle-scars arranged in a U-shaped line. FLOWERS — Appear about June after the new leaves are fully developed, are arranged in umbel-like clusters about 4-5 inches in diameter and borne on glandular pedicels. Individual flowers are perfect, pale rose to white in color; upper petals marked by yellowish -green dots. FRUIT — A dark reddish-brown capsule about J of an inch long, which persists until the following season. Capsules split open lengthwise liberating oblong flattened seeds. Surrounded at the base by persistent calyx and terminated by persistent linear style. WOOD — Diffuse-porous; hard, strong, brittle, light brown with lighter sapwood. Weighs 39.28 Ibs. per cubic foot. Of little commercial use but occasionally manufactured into tool handles and engraving blocks. Excellent for fuel where it reaches a fair size. V DISTINGUISHING CHARACTERISTICS— The Great Laurel, also known as Rhododendron and Rose Bay, can be distinguished from all other species of trees native to Pennsylvania by its large, persistent, leathery, simple leaves which are clustered .towards the end of the branches and alternate in their arrangement. Its shrubby form and its preference for moist habitats also aid in distinguishing it. The conical flower-buds, which are usually terminal and often over an inch long, are also characteristic. The twigs are evidently marked by the bud-scale scars. RANGE — Nova Scotia anc. Lake Erie on the north, south along the mountains to northern Georgia. DISTRIBUTION IN PENNSYLVANIA— Found throughout the State. Rare in the southeastern and western parts. Abundant throughout the mountainous parts. HABITAT — In the North frequents a cold swampy situation. In the South it ascends the mountains to 3,000 feet but remains along tfie banks of streams. Tolerates most soils except limestone. IMPORTANCE OF THE SPECIES — The Rhododendron does not reach a large enough size in Pennsylvania to produce wood of commercial importance. In the South it often becomes a tree. It is the most attractive shrub in our flora, and will thrive in a variety of situations but prefers moist locations and flees from soils which contain lime. PLATE CXX. GREAT LAUREL. 1. Branch with mature and immature leaves, and a cluster of open flowers, x 2. 2. A fruiting branch with a large terminal bud, x J. 3. Cross-section of a fruit capsule showing five cells, natural size. PLATE CXXI. SOUR-WOOD. 1. A flowering branch with long one-sided racemes of flowers clustered in an open panicle, x 2. A few racemes of fruit, x J. 3. Cross-section of a capsule showing five cells filled with seeds, slightly enlarged. 4. A winter twig, enlarged. 5. Section of a winter twig, enlarged. 209 SOUR-WOOD. Oxydendrum arboreum, (Linnaeus) De Candolle. GENUS DESCRIPTION — The Sour-wood is the sole representative of the genus Oxydendrum. The word Oxydendrum means acid tree, in allusion to the acid foliage. FORM — A medium-sized tree which may reach a height of 50-60 ft. with a diameter of 20 Inches, but usually is about '25 ft. in height with a diameter of 8 inches. Trunk usually straight, tall, slender, and bears a narrow round-topped crown. BARK — Rather thick, roughened by fissures which separate rounded ridges covered with thick scales. On old trunks grayish often tinged with red; on young branches reddish-brown. TWIGS — Rather slender, at first yellowish-green, later orange-colored and reddish-brown. Marked with numerous, oblong, elevated lenticels. BUDS — Alternate, axillary; terminal buds absent; small, partly imbedded in the bark, acute at apex, covered with several opposite dark red scales. LEAVES — Alternate, simple, oblong, stalked, acute- at apex, wedge-shaped at base, serrate on margin, very smooth, 5-7 inches long, li-2i inches wide. LEAF-SCARS — Alternate, elevated, nearly triangular, with a single compounded bundle-scar. FLOWERS — Appear about July. White, perfect, with cylindrical corolla, and borne in racemes often 6-8 inches long. FRUIT — A 5-sided, K-valved capsule terminated by a persistent style. Matures in September only a month or six weeks after the flowers. Capsules often persist in clusters. WOOD — Diffuse-porous; hard, heavy, compact, reddish-brown with lighter sapwood. Medullary rays are numerous but narrow. Weighs 46.48 Ibs. per cubic foot. Used locally for runners of the Appalachian tanbark sleds, and for tool handles. DISTINGUISHING CHARACTERISTICS — The Sour-wood, also known as Sorrel-tree and Sour Gum, can be distinguished in summer by its white bell-shaped flowers which are arranged In racemes resembling the lily-of-the-valley. The alternate bitter leaves which resemble the peach leaf are also characteristic. The bark on older trees resembles that of the Black Gum. The winter buds, which art dark red, alternate, very small, often partly inbedded by bark, are also characteristic. RANGE — Pennsylvania and Indiana south to Florida and western Louisiana. DISTRIBUTION IN PENNSYLVANIA— Found only sparsely in the southwestern part of the State. HABITAT — Usually frequents well-drained soils. Commonly found on hillsides, seldom along streams. IMPORTANCE OF THE SPECIES — The Sour- wood is native only .to a very small portion of southern Pennsylvania. Its small size and limited distribution in this State prevent it from being recommended for fores- tr$ purposes. It is, however, an attractive ornamental tree on account of its form, late flowering, beautiful and attractive autumnal foliage. 14 210 COMMON PERSIMMON. Diospyros virginiana, Linnaeus. FAMILY AND GENUS DESCRIPTION— The Ebony family, Ebenaceae, is widely distributed iu the tropics, and only a few representatives are found in the temperate regions. It comprises about 6 genera with more than 250 species. The most important genus is Diospyros which has 2 representatives in the flora of the United States and 1 in Pennsylvania. This genus comprises about 160 species found mostly in the tropics. Members of this genus produce some of the ebony of commerce, and valuable foods in China and Japan. The species described below is the sole representative of this genus in eastern North America. One other species is found in the southern and western parts of Texas. FORM — A small tree usually from 25 to 50 ft. in height with a diameter of less than 12 inches, but may reach a height of 100 ft. with a diameter of 2 feet. Trunk usually short and Blender. Crown high and broad-topped. It often spreads by roots migrating under the ground, forming dense thickets. BARE — On old trunks thick, hard, dark gray to dark brown or black, cinnamon-red at the bottom of the fissures; separates into thick squarish blocks which peel off into thin scales. See Fig. 101. TWIGS — Slender, bittar, astringent, grayish to reddish-brown becoming darker in second year, usually pale pubescent, covered with a few scattered orange-colored lenticels, and contain large pith or pith chamber. BUDS — Alternate, broadly ovate, closely pressed against twig, I of an Inch long, sharp- pointed, covered by 2 dark brown glossy scales; terminal bud absent. LEAVES — Alternate, simple, oval, acute at apex, entire on margin, wedge-shaped to heart- shaped at base, 4-6 inches long, thick, dark green and shiny above, often hairy below. Leaf- stalks are i-1 inch long, and contain 1 fibro-vascular bundle. LEAF-SCARS — Alternate, elevated, flattened, contain 1 prominent bundle-scar which Is trans- versely-elongated, or several becoming confluent. FLOWERS — White, appearing about May or June. Staminate and pistillate flowers occur separate. Staminate arranged in 2-3-flowered cymes. Pistillate solitary, and borne on short stalks. FRUIT — A juicy, spherical, orange-colored, often red-cheeked berry with remnants of style persisting and seated in enlarged green calyx. Often very astringent. Sometimes edible be- fore frost appears. Contains from 1-8 seeds, usually 4-6. WOOD — Diffuse-porous: heavy, hard, compact, susceptible to a high polish, strong; heart- wood is brown to black but usually forms late; sapwood is wide, yellowish and often streaked with black. Weighs about 49 Ibs. per cubic foot. Used for shuttles, gold heads, billiard cuea, mallets, parquet flooring, brush backs, veneer. DISTINGUISHING CHARACTERISTICS — The Persimmon, also known as Date-plum and Pos- sum-wood, can be distinguished in summer by its alternate, simple, entire-margined, deep green leaves with only 1 fibro-vascular bundle in the leaf-stalk and the rough bark which is often broken up into quadrangular blocks and is evidently cinnamon-red at the base of the fissures. In autumn the fruit is characteristic. In winter the rough bark with cinnamon-red color at the bottom of the fissure, the semi-orbicular leaf-scars with only 1 bundle-scar, the broadly ovate buds with 2 dark brown scales, the reddish-brown slightly pubescent twigs with relatively large pith or pith cavity, and the persistent remnants of flowers are distinctive. RANGE — Connecticut to Florida, westward to Iowa and Texas. DISTRIBUTION IN PENNSYLVANIA — Common in the eastern and southern parts of the State. Abundant on Gettysburg battlefield. Local in southwestern part of the State. Absent in the higher mountainous parts. HABITAT — Prefers a light, somewhat sandy well-drained soil. Tolerates rich bottomlands especially in the South. IMPORTANCE OF THE SPECIES — The Persimmon is too small in size and too limited in dis- tribution in this State to be of commercial importance from the point of view of wood produc- tion. It is essentially a southern tree. The tree has an attractive form, beautiful clean foliage, and an exceptionally attractive bark. It rarely exceeds 40 feet in height with a diameter of 12 Inches in this State. PLATE CXXII. COMMON PERSIMMON. 1. A branch with pistillate flowers, x J. 2. A branch with staminate flowers, x |. 3. A fruiting branch with mature leaves, x 4 4. A winter twig, natural size. 5. Section of a winter twig, enlarged. PLATE CXXIII. CATALPA. 1. A panicle of flowers, x J. 2. A branch with two drooping cigar-like fruits, the one split open showing the seeds, x 3. A winged seed, x i. 4. A winter twig, x J. See Plate II. 211 CATALPA. Catalpa bignonioides, Walter. FAMILY AND GENUS DESCRIPTION — This tree belongs to the Bigmmia family, Bignoni- aceae, which comprises about 100 genera with 1,500 species. Most of the representatives of this family occur in the tropics; only a few are found in the temperate zone. They occur as trees, shrubs, woody climbers, or rarely herbs. North America has only 6 genera with 8 species in its flora and Pennsylvania 3 genera with 3 species. The genus Catalpa is the only one which has tree representatives occuring rather frequently in this State. This genus comprises about 7 species in the world, of which number 2 are native to North America. No representative of this genus is native to Pennsylvania but 1 species has been naturalized so extensively in every part of the State, that a description of it in this publication was considered desirable. FORM — Usually 25-40 ft. high but may reach a height of 60 ft., with a .diameter of 3 feet. Trunk usually short, crooked, often angular, and unattractive. Crown high, broad, and rather symmetrical in appearance in summer, due to the dense foliage. BARK — Light brown, rather thin, shallowly-ridged, scaly, bitter. TWIGS — Stout, smooth, or slightly downy, yellowish-brown, usually frozen back, covered with numerous large lenticels, roughened by leaf-scars. Pith large, white sometimes chambered at the nodes. See Plate II, 2. BUDS — Terminal bud usually absent. Lateral buds small, almost inbedded in bark, usually less than i of an inch long, covered with 5-6 visible, small, brown bud-scales. LEAVES — Opposite or whorled i. e., more than two at a node, simple, 6-10 inches long, 4-5 inches broad, ovate, heart-shaped at base, acute at apex, entire or wavy on margin. Fall simultaneously after first heavy frost. LEAF-SCARS — Opposite or 3 at a node, large, conspicuous, with projecting margin, elliptical in outline, with conspicuous bundle-scars usually arranged in an ellipse. FLOWERS — Appear in June or July. Perfect, arranged in many-flowered crowded panicles from 8-10 inches long. Corolla is conspicuously spotted on inner surface. FRUIT — A long, cylindrical, bean-like capsule which often persists far into winter and con- tains many flattened winged seeds. Wings surround seeds and are fringed at ends. Tree is sometimes called Indian Bean on account of fruit. WOOD — Ring-porous; distinct demarcation between heartwood and sapwood; odor somewhat like kerosene; light, soft, coarse-grained; durable in contact with soil, light brown, and has a satiny surface. Weighs about 26 Ibs. per cubic foot. Used mainly for cross-ties, posts and poles. DISTINGUISHING CHARACTERISTICS — The Eastern Catalpa, also known as Catalpa, Indian Bean, and Cigar Tree, can be distinguished in summer by its leaves which are opposite or whorled and its large panicles of flowers. The cigar-like or bean-like fruit is characteristic in autumn and winter. In winter it can be distinguished by its large elliptical leaf-scars which are opposite or whorled and have their bundle-scars arranged in an ellipse. The pith is sometimes chambered at the nodes. The Eastern Catalpa closely resembles the Western Catalpa but has slenderer and thinner walled fruit, larger flower-clusters, more distinct markings on inner surface of corolla, and more blunt-pointed leaves. The Western Catalpa is more frost hardy than the Eastern Catalpa. RANGE — Original range was limited to parts of Georgia, Alabama, Mississippi and Florida. At present found in all parts of the country east of the Rocky Mountains and as far North as New England. DISTRIBUTION IN PENNSYLVANIA — Planted for ornamental purposes in many parts of the State and has escaped cultivation in practically every part of the State. Individual specimens or small groups of trees are common in the forest near settlements. HABITAT Prefers moist and fertile situations, is most common along streams and river banks, but also found in drier places. Prefers shaded to open situations. IMPORTANCE OF THE SPECIES — Two species of Catalpa are commonly recognized, the Eastern Cataipa and the Western or Hardy Catalpa. Both have been widely advertised. The Western species is hardier against frost and produces a straighter and cleaner trunk. Neither of the 2 species should be planted for forestry purposes in this State. Both species produce beauti- ful flowers and foliage and attractive fruit. 212 THE OLIVE FAMILY— OLEACEAE. The Olive family comprises representatives which are widely dis- tributed in temperate and tropical regions, but are commonest in the northern portion of both hemispheres. A great variety of trees and shrubs is embraced by this family, some of which are valuable timber trees, while others are valuable for ornamental purposes or for the food which they yield. The most important is the Olive Tree (Olea Europaea, L.), whose fruit and the oil derived from it are used almost universally as food. The Olive Tree was cultivated in ancient times in Syria and Palestine ; later it was introduced into the Mediterranean region, where one can find large orchards of it at the present time; and within the past few decades it has been intro- duced on a large scale into the southwestern part of the United States. A few specimens are also growing at the present time near Mont Alto, Pennsylvania. The Ashes which are among our most valuable timber trees, the Forsythias and Lilacs which are among our most attractive and popular shrubs, and the Privets, which are used so extensively as hedge plants, are also members of this family. The Olive family comprises about 21 genera with 500 species of trees, shrubs, and a few herbs. The flora of North America contains 5 genera with about 20 species, while that of Pennsylvania contains 4 genera with 9 species. Only 2 of the 4 genera native to Pennsyl- vania have tree representatives. KEY TO THE GENERA. Page. 1, Leaves compound; fruit a dry samara; flowers without a corolla; winter buds with 3-4 pairs of scales, Fraxinus 213 1. Leaves simple; fruit a fleshy berry; flowers with a corolla; winter buds with more than 4 pairs of scales, Chionanthus 217 THE ASHES— FRAXINUS, (Tourn.) L. The Ashes with one or two exceptions are trees, which occupy a variety of situations but prefer rich, moist soil. Some species may also be found occasionally in swamps or along streams, while others frequent dry and poor uplands. The trees are usually straight, have little stem taper, and often attain large dimensions. They are, lo- cally, rather abundant and yield wood which is straight-grained, strong, and elastic. The wood of all the eastern species except that of the Black Ash, is sold as White Ash. This classification is legi- timate since there is little difference for practical purposes. They are also valuable as shade trees. Our native species and the intro- duced European species (Fraxinus excelsior, L.) are planted rather extensively in parks and lawns. The trunk and leaves of Fraxinus ornus, L., a species of southern Europe and Asia Minor, yield the manna of commerce. The Ashes may be regenerated by natural and artificial methods. The natural regeneration may be accomplished by means of regulated 213 cutting of the mature trees accompanied by the establishment of a young growth from the seed scattered by the seed trees which remain, or by means of coppicing. Coppicing is a practical method of regen- eration especially on rich, moist soils and where very large sizes are not required. The artificial regeneration may be accomplished by sowing seeds, or what is still better, by collecting the seeds, planting them in the nursery, and after a year's growth in the nur- sery, lifting them and planting them out upon the area where they are to remain and produce a timber crop. The leaves of the Ashes are opposite and compound. The leaf- lets occur in 2s opposite each other along the principal leaf-stalk with a single leaflet at the end, hence the total number of leaflets is always odd. The twigs are stout and occur in pairs opposite each other along the main axis. The branchlets are usually flattened at the nodes. The flowers are produced in dense clusters and usually appear in spring before the leaves have made their appearance. The fruit, known as a samara, matures in fall and occurs in clusters. The individual seed is winged at one end. This wing aids in the dis- persal of the seed by the wind, which is the most important disper- sing agent ; but water may also scatter a large quantity of the seeds, especially of such species which are commonest near streams or where flood waters occur. The Ashes are distributed throughout the north temperate zone and comprise about 40 known species, of which number 16 occur in North America and 4 in Pennsylvania. Three species are common in this State, while another species known as the Biltmore Ash (Fraxinus Biltmoreana, Beadle), is found locally only over a limited region in the southern part of the State. A variety of the Ked Ash known as the Green Ash (Fraxinus pennsylvanica var. lanceolata) is also found locally in the southern part of the State. SUMMER KEY TO THE SPECIES. Page. 1. Leaves with sessile leaflets; seed surrounded by wing; bark scaly, not furrowed with diamond-shaped fissures, F. nigra 215 1. Leaves with stalked leaflets: seed partly surrounded by wing; bark furrowed with diamond-shaped fissures, 2 2. Leaves and twigs smooth or nearly so; seed usually winged only at apex F, americana 214 2. Leaves and twigs velvety pubescent; seed winged usually at apex and sides, F. pennsylvanica 216 WINTER KEY TO THE SPECIES. 1. Buds usually black and acute at apex; bark scaly, not furrowed with diamond- shaped fissures; tall and slender, F. nigra 215 1. Buds rusty to dark brown, usually obtuse at apex; bark furrowed with diamond- shaped fissures; tall but stout, 2 2. Twigs smooth or nearly so; leaf -scars evidently indented on upper margin, .... F. amfericana 214 2. Twigs velvety pubescent; leaf -scars not evidently indented on upper surface, .... F. pennsylvanica 2U 214 WHITE ASH. Fraxinus americana, Linnaeus. FORM— Usually reaches a height of 70-80 ft. with a diameter of 2-3 ft., but may attain a height of 120 ft. with a diameter of 5-6 ft. Trunk usually tall, massive, clear from branches for a considerable distance from the ground when grown in the forest, bearing a narrow, some- what pyramidal crown. When open grown the crown is decidedly round-topped and often extends almost to the ground. In forest grown trees trunk often continuous and dividing Into a number of spreading branches. BARK — Grayish-brown, rather thick upon older trunks, decidedly divided by diamond-shaped fissures into rather flattened ridges which are covered by thin, close-fitting scales. Longitudinal ridges often transversely-fissured so that the primary fissures are connected. See Fig. 86. TWIGS — Opposite, stout, usually smooth, sometimes covered with a slight bloom, decidedly flattened at the nodes. During the first winter grayish-brown in color, and decidedly lustrous; covered by scattered, large, pale lenticels. BUDS — Opposite; ovate, blunt-pointed, usually dark brown, occasionally almost black. Term- inal bud larger than laterals, covered by 2-3 pairs of visible scales which occur opposite each other. Scales on the terminal buds may be somewhat sharp-pointed, while those on the lateral buds are usually obtuse. Two lateral buds are usually found at base of terminal bud causing* a terminal enlargement of twig. LEAVES — Opposite, compound, about 10 inches long with 5-9 leaflets. Leaflets 3-5 inches long, about Ij inches broad, evidently-stalked, slightly serrate on margin, acute at apex, wedge-shaped to rounded at base. When full grown usually smooth and dark green above and pale below. A few hairs are sometimes found along the veins on the lower surface. LEAF-SCARS — Opposite, semi-circular In outline, notched on the upper margin, raised, con- spicuous; bundle-scars small, numerous, arranged In a curved line. FLOWERS — Appear about May before the leaves. The staminate and pistillate on different trees. Staminate occur in dense reddish-purple clusters: pistillate in rather open panicles. FRUIT — A samara borne in dense drooping panicles about 7 Inches long. Panicles often persist far into winter. Individual samara 1-2 inches long, consists of a seed bearing portion and a winged portion. Seed portion round in cross-section, terminated by the wing which aids in the dispersal of the seed. Since some trees bear staminate flowers only, seeds are never found upon them. Trees bearing pistillate flowers alone produce seeds. WOOD — Ring-porous; very heavy and strong, odorless and tasteless, tough, elastic, and brown, with thick and much lighter colored sapwood. Pores in spring wood large, usually 3-10 rows wide. Pores in summer wood isolated or in groups of 2-3, and usually Joined by wood paren- chyma. Weighs 40.77 Ibs. per' cubic foot. Used in the manufacture of agricultural implements, wagon building, furniture, interior finishing of houses, and for tool handles. DISTINGUISHING CHARACTERISTICS— The White Ash, also known as the Canadian Ash, can be distinguished from the Black Ash by its leaves, which have stalked leaflets, while the leaflets of the Black Ash arc sessile. The buds of the White Ash are usually obtuse and brown in color, while those of the Black Ash are usually acute and black in color. The bark of the White Ash is usually furrowed and has diamond-shaped fissures between the ridges, while the bark of the Black Ash is scaly, often corky and not furrowed. It can be distinguished from the Red Ash by its smooth leaves and twigs. Those of the Red Ash are usually velvety-pubescent. The leaf -scars of the White Ash are usually evidently -indented in the upper margin, while those of the Red Ash are not. The seeds of the White Ash have wings which are fastened only to the apex of the seed, while in the Red Ash they are fastened to the apex and often extend down along the sides, and in the Black Ash the wing usually surrounds the seed. RANGE — Nova Scotia to Minnesota and southward to Florida and Texas. DISTRIBUTION IN PENNSYLVANIA— Generally distributed throughout the State. Common in the eastern, southern, and western parts. Sparse in the mountainous parts, except in moist valleys and rich bottomlands. HABITAT — Prefers fertile, moist soils; very common in rich, moist woods and along streams, lakes, and other bodies of water. Occasionally found on rather dry hillsides. IMPORTANCE OF THE SPECIES — The White Ash is one of the most important timber trees of Pennsylvania on account of the large size which it attains, its general distribution through- out the State, its rapid growth, as well as its immunity from the attack of fungous diseases and Insects. Nature did not produce it in pure stands, hence in developing our future forests we should aim to follow nature and plant White Ash in mixture with some other desirable species. White Ash and White Pine will undoubtedly prove to be a valuable mixture. PLATE CXXIV. WHITE ASH. 1. A branch with a cluster of staminate flowers 2. A panicle of pistillate flowers, x 5. 3. A mature compound leaf, x |. 4. A cluster of fruit, x J. 5. A winter twig, x 1. 6. Section of a winter twi*. enlarged. and immature leaves, x J. PLATE CXXV. BLACK ASH. 1. Branch with staminate Sowers, x 1. 2. A panicle of pistillate flowers, x J. 3. A mature compound leaf, x j. 4. A cluster of fruit, x J. 5. A winter twig, x J. 6. Section of a winter twig, enlarged. 215 BLACK ASH. Fraxinus nigra, Marshall. FORM — A medium-sized tree which usually attains a height of GO-80 ft. with a diameter of 1-2 ft., but may reach a height of 100 ft. with a diameter of 2J feet. It usually has a rather tall, slender trunk often free from branches for a considerable distance from the ground bearing a narrow and shallow crown formed by numerous rather upright branches. Usually found in the forest, where the slender form prevails, but occasionally may be found in the open, where its form resembles that of the White Ash. BARK — Thin, grayish, shallowly and irregularly fissured; ridges between the fissures decidedly scaly and somewhat corky. By rubbing the bark it breaks up into a very fine powder. See Fig. 87. TWIGS — Rather stout, at first somewhat hairy, but soon becoming quite smooth. Resemble those of the White Ash but lighter in color, and not so smooth and glossy. BUDS — Opposite; terminal bud present, ovate, sharp-pointed, black, covered with 1-2 pairs of visible bud-scales, usually at some distance from nearest lateral buds; lateral buds usually almost as broad as long, often obtuse at apex, closely oppressed to twigs. LEAVES— Opposite, compound, about 14 inches long, with 7-11 sessile leaflets. Leaflets are all sessile except the terminal one, 3-5 inches long, about 15 inches wide, acute at the apex, serrate en the margin, wedge-shaped at the base, dark green and smooth above, paler below. LEAF-SCARS — Opposite, large, conspicuous, crescent-shaped, upper margin usually straight or convex; bundle-scars numerous arranged in a curved line, sometimes joined so as to form a compound scar. FLOWERS — Appear about May before the leaves. Staminate and pistillate borne on the same or different trees; the staminate in dense, dark purplish clusters; the pistillate in rather open panicles. FRUIT — A samara which resembles the fruit of the White and Red Ashes, but differs in that the wing is broader, decidedly notched at the apex, and completely surrounds the somewhat flattened seed bearing portion. WOOD — Ring-porous; heavy, smooth, soft, not strong, rather coarse grained, somewhat dur- able. Heartwood dark brown with white sapwood; marked difference between spring and sum- mer wood; annual layers of the wood easily separated. Pores in spring wood in a broad zone often comprising one-half of the ring. Pores in summer wood large, few, scattered. Weighs 39.37 Ibs. per cubic foot. Used in the manufacture of baskets, hoops, chair bottoms, and the interior finishing of houses. DISTINGUISHING CHARACTERISTICS— The Black Ash, also known as Hoop, Swamp, Basket, and Brown Ash, can readily be distinguished from all the other species of Ash in Pennsylvania in summer by its opposite and compound leaves with sessile leaflets. The leaflets of all other species of Ashes are evidently-stalked. In winter it can be recognized by its black and acute buds, its scaly, non-fissured bark, and its tall and slender form. In autumn by its fruit with a flattish body which passes insensibly into the wing. RANGE — Newfoundland to Manitoba, south to Virginia and Arkansas. DISTRIBUTION IN PENNSYLVANIA— Generally distributed over the State. Common in the eastern, southern, and central parts. Local in the western part. Rare in mountainous portion except in moist valleys. HABITAT — Prefers swampy habitats, in this respect differing very much from the other species of Ash native to the State. Flourishes best in the cooler portions of its range. Seldom thrives on dry ground. IMPORTANCE OF THE SPECIES — This species has probably never been grown for forestry purposes. It may be so recommended where natural reproduction may be depended upon and in such locations where other more valuable trees will not grow. Few better species grow in its chosen home and consequently it may be one which we will plant in the future in extremely wet locations together with others such as Spruce, Fir, and Larch. 216 RED ASH. Fraxinus pennsylvanica, Marshall. FORM — Tree of middle or large size, usually attaining a height of 30-60 ft. with a diameter of 1-8 ft., but may reach a height of 70 ft. with a diameter of 5 feet. Trunk similar to that of White Ash, but smaller and bearing numerous upright branches which form a rather irregular and compact crown. BARK — Grayish-browu, roughened by numerous fissures separating prominent ridges which In time become scaly. Fissures usually diamond-shaped. Ridges often sub-divided by transverse secondary fissures. TWIGS— Similar to those of the White Ash but not so stout and covered with a dense velvety pubescence, or sometimes almost smooth. See "Twigs" under White Ash, page 214. BUDS — Opposite; terminal bud present; ovate, brown, covered by brownish scales, 2 pairs of which are usually visible. Scales of the lateral buds usually have an obtuse apex while those of the terminal buds have a more acute apex. See "Buds" under White Ash, page 214. LEAVES — Opposite, compound, about 11 inches long, with 5-9 stalked leaflets. Leaflets from 3-5 inches long, 1-15 inches wide, ovate, acute at apex, slightly toothed on margin, wedge- shaped at base. At first coated on the lower surface with white tomentum, later becoming yellowish-green above, and decidedly velvety-pubescent beneath. LEAF-SCARS — Opposite; semi-circular in outline, conspicuous, slightly notched on the upper margin; bundle-scars numerous, usually small, and arranged in a curved line. Sometimes a number of bundle-scars unite to form a compound bundle-scar. FLOWERS — Appear about May before or with the leaves. Staminate and pistillate are usually borne on different trees. Staminate occur in dense purplish-red clusters; pistillate in open greenish-red panicles. FRUIT — A samara, borne in open panicles which often persist far into winter. The individual samara varies in length from 1-2 inches, and consists of a seed bearing portion and a winged portion. Fruit resembles that of the White Ash, but has the winged portion attached not only to the apex of the seed but also along the sides, while the White Ash has the wing attached at the apex only. WOOD — Ring-porous; heavy, hard, rather strong, light brown, with rather wide and light colored sapwood. Pores in the spring and summer wood are similar to those of the White Ash, but the lines of pores in the summer wood are longer than in the White Ash. Weighs 44.35 Ibs. per cubic foot. Used for the same purposes as the White Ash, but is somewhat in- ferior to it from a commercial point of view. DISTINGUISHING CHARACTERISTICS— The Red Ash can be distinguished at any season of the year from the other species of Ash native to Pennsylvania by its velvety-pubescent twigs and petioles. In addition it can be distinguished from the White Ash by its fruit, the wings of which are attached to the apex and the sides of the seeds, while those of the White Ash are at- tached at the apex only. The leaflets of the Red Ash are decidedly stalked while those of the Black Ash are sessile. The buds of the Red Ash are brown in color and usually obtuse, while those of the Black Ash are black in color and usually acute. The bark of the Red Ash is prominently-fissured while that of the Black Ash is not fissured but decidedly scaly and presents somewhat of a corky appearance. RANGE — Vermont west to Minnesota and southward to Florida and Texas. DISTRIBUTION IN PENNSYLVANIA— Found in the eastern and southern parts of the State. Not known to occur in other parts. HABITAT — Prefers rich soil in valleys; also found in swampy lowlands and along the margins of streams, lakes, and ponds; occasionally found upon rather dry hillsides. IMPORTANCE OF THE SPECIES — The Red Ash in many respects resembles the White Ash, but it is of less economic importance since it does not attain so large a size as the White Ash, its wood is not quite so valuable, and it requires a somewhat moister soil. The White Ash will grow in all places where the Red Ash thrives, and consequently the White Ash should be favored. It is sometimes planted for ornamental purposes but the White Ash is generally regarded more attractive and just as free from the attacks of insects and fungi. The only place where the Red Ash could be recommended for planting for forestry purposes would be in $uch situations where it is too wet for the White Ash to thrive. PLATE CXXVI. RED ASH. 1. Branch with staraiuate flowers, x i. 2. A panicle of pistillate flowers, x J. 3. A mature compound leaf, x J. 4. A cluster of fruit, x J. 5. A winter twig, x J. 6. Section of a winter twig, enlarged. PLATE CXXVII. FRINGE-TREE. 1. A flowering branch with immature leaves, x J 2. A fruiting branch with mature leaves, x 1. 3. A winter twig, x \. 4. Section of a winter twig, natural size. 217 FRINGE-TREE. Chionanthus virginica, Linnaeus. GENUS DESCRIPTION— The genus to which the Fringe-tree belongs has only one other rep- resentative. Both species are cultivated primarily for ornamental purposes. The generic name of these trees, Chionanthus, refers to the white flowers which resemble snow. FORM — A slender, small-sized tree usually attaining a height of 20 ft. with a diameter of 6-8 inches, but may reach a height of 40 ft. with a diameter of 12 inches. Trunk usually short, bearing numerous, stout, and ascending branches which form a rather deep, narrow crown. BARK — On main trunk rather thin, scaly, reddish-brown; on branches light brown to orange, and smooth. TWIGS— Rather stout, light brown tinged with green, somewhat angled, slightly hairy. Marked by large, conspicuous and elevated leaf-scars and dark colored lenticels. BUDS — Opposite, ovoid, sharp-pointed, about $ of an inch long, covered with about 5 pairs of scales which increase in length from the outer surface and ciliated on the margin. LEAVES — Simple, opposite, thickish, ovate, 4-8 inches long, 1-4 Inches wide, wedge-shaped at base, entire on margin, acute at apex, dark green above, pale and smooth below except along the veins. LEAF-SCARS — Opposite, raised, semi-circular in outline, upper side of margin partly surrounds bud; bundle-scars solitary, large, located on cushions. FLOWERS — Appear in May or June when leaves aYe Just developing. Borne in drooping panicles about 4-6 inches long; perfect, white, and slightly fragrant. The appearance of the snow white flowers resembles fringe, hence the common name Fringe-tree. FRUIT — A berry, borne in loose clusters. Dark blue in color, about $-f of an inch long, and surrounded at the base by a persistent calyx. Stalks bearing the fruit may bear leaf-like bracts. Skin of fruit usually thick and stones usually thin. WOOD — Light brown in color, with rather wide and lighter colored sapwood; heavy, hard, close-grained. Weighs about 40 Ibs. per cubic foot. It is put to no special commercial uses. DISTINGUISHING CHARACTERISTICS — The Fringe-tree, also known as Old Man's Beard, White Fringe, American Fringe, Flowering Ash, and Snow Flower tree, is native to only a few counties in the southern part of the State. This limited distribution, together with its small size and its simple, opposite, entire-margined and thick leaves will enable one to dis- tinguish it quite readily during the summer. The white fringe-like panicles of flowers will also assist during a limited portion of early summer. In winter, the opposite, rather stout branches bearing sharp-pointed, opposite buds covered with more than 4 pairs of scales, are also charac- teristic. The berry-like fruit combined with the opposite branching will distinguish this tree from practically all others found in the State. RANGE — Southern New Jersey and southeastern Pennsylvania to Florida and Texas. It is essentially a southern species. DISTRIBUTION IN PENNSYLVANIA— This tree is found locally in about 6 counties in the southeastern part of the State. It Is nowhere abundant, nor does it attain any large dimensions. HABITAT — Usually found In rich, moist soil; also frequents banks of streams, lakes and swamps. IMPORTANCE OF THE SPECIES— The Fringe-tree is planted extensively for ornamental purposes as far north as Massachusetts. Its beautiful flowers and its attractive form recommend it for planting in lawns and parks. The main objectionable feature is the fact that it retains its foliage for a relatively short period during the summer, since the leaves are late to appear and early to disappear. The poor quality and small size of the wood which it produces, to- gether with its limited distribution and selective situations, do not recommend it for forestry purposes. It can readily be grafted upon our common species of Ashes. This enables one to develop it upon situations somewhat dry for the tree itself. 218 SWEET VIBURNUM. Viburnum Lentago, Linnaeus. FAMILY AND GENUS DESCRIPTION— The Honeysuckle family, Caprifoliaceae, is rather widely distributed in temperate regions. It comprises about 10 genera with 275 species of shrubs, trees, vines, and a few perennial herbs. About 8 genera are native to North America and 7 to Pennsylvania. The 7 genera native to this State comprise about 31 species, most of which are shrubs. The principal native genera are: The Elderberries (Sambucus), the Viburnums (Viburnum), the Bush Honeysuckles (Diervilla), the Honeysuckles (Lonicera) and the Snowberries (Symphoricarpos). Since most of the representatives of these genera are shrubs only a few have been discussed in this publication. A description of the others may be found in Gray's New Manual of Botany, or Porter's Flora of Pennsylvania. The Elders, belonging to the genus Sambucus, are among our best known shrubs. The Common Elderberry (Sambucus canadensis L.) is probably the best known. The flowers are conspicuous and sometimes used in making wine. The fruit is eaten and also made into wine, pies, and jellies. The Honeysuckles (Ixmicera) are very common in our gardens and parks as ornamental shrubs and vines. They comprise about 100 species of which number at least 10 species are native to Pennsylvania. The Viburnums (Viburnum) also comprise about 100 species of which number about 20 species are native to North America and 11 to Pennsylvania. All of our species are usually shrubs, rarely small trees. The two species described on the following pages are occasionally found as small trees. FORM — A shrub or small tree usually attaining a height of 10-15 ft., but may reach a height of 30 ft. with a diameter of 10 inches. Trunk usually short, bearing a round-topped crown formed by slender and usually drooping branches. BARK — Disagreeable in odor, reddish, roughened in older specimens by division and subdivision into thick plates which are scaly on the surface. TWIGS — At first greenish and covered with rusty hairs, later reddish to orange and rather smooth. BUDS — Opposite, long, slender, scurfy, reddish-brown, covered by two rather rough scales. Lateral buds are usually leaf-buds and closely appressed to twigs. Terminal buds are often flower buds with a marked swelling at the base, and about 1 of an inch long. LEAVES — Opposite, simple, ovate, about 2i inches long, sharp-pointed, narrowed or rounded at base, closely and very sharply serrate on margin, bright green, smooth on both upper and lower surfaces. Veins conspicuously connected by veinlets. • Petioles often winged and grooved. LEAF-SCARS — Opposite, wide, broadly U-shaped, not encircling twigs, and usually with 3 bundle-scars. FLOWERS — Small, perfect, white, appearing in May or June in dense, many-flowered, sessile, terminal cymes which are usually 3-5 inches broad. FRUIT — A black or dark blue fleshy, sweet, rather juicy drupe, containing a flat oval stone, and grouped into small clusters borne on slender, reddish, and often drooping stalks. WOOD — Diffuse-porous; heavy, hard, dense, yellowish-brown, with very disagreeable and per sistent odor. Weighs 45.51 Ibs. per cubic foot. Not important commercially. DISTINGUISHING CHARACTERISTICS— The Sweet Viburnum, also known as Sheepberry, Nannybery, and Wild Raisin, resembles the Black Haw more closely than any other of our native Viburnums. It can be distinguished from the latter by its leaf-blades with acuminate apexes, its long-pointed buds, and its winged petioles. The Black Haw has leaf-blades with obtuse or merely acute apexes, short-pointed buds, and no winged leaf-petioles. The small lateral branches of the Black Haw are often stiff and stand out almost at right angles to the main axis, while those of tha Sweet Viburnum are flexible and more erect. RANGE — Quebec to Manitoba, south to Georgia, Indiana and Missouri. DISTRIBUTION IN PENNSYLVANIA — Common in the eastern, southern, and central parts of the State; local in the western part, and less frequent in the northern part. HABITAT — Usually found along or near banks of streams and borders of lakes located in or pear wooded areas. IMPORTANCE OF THE SPECIES — The Sweet Viburnum has no commercial value, so far as wood production is concerned. Its form, flowers, fruit, and foliage make it one of the most attractive of our small ornamental trees, PLATE CXXVIII. SWEET VIBURNUM. 1. A twig showing the opening of a terminal bud, x J. 2. A branchlet with leaves and two cymes of flowers, x J. 3. A branchlet with leaves and two clusters of fruit, x 5. 4. A winter twig with lateral leaf-buds and terminal flower 5. A leaf-scar with three bundle-scars, enlarged. buds, natural size. PLATE CXXIX. BLACK HAW. 1. A branchlet with leaves and two cymes of flowers, x J. 2. A branchlet with leaves and two clusters of fruit, x J. 3. A winter twig with a large terminal flower bud and three leaf-buds. Two leaf-buds are op- posite, and located about the middle of the twig, while the third is at the base and to the right of the terminal flower bud, natural size. 219 BLACK HAW. Viburnum prunifolium, Linnaeus. FORM — A shrub or small tree usually attaining a height of 15 ft., but may reach a height of 35 ft. with a diameter of 10-12 inches. Trunk short, often crooked, bearing a rather broad and round-topped crown formed by stiff lateral branches. BARK — About 2/5 of an inch thick, reddish-brown, rough, broken into thick plate-like scales. TWIGS — At first reddish and smooth, then green, and later, during first winter, spine-like, gray tinged with red, and often covered with thin film-like bloom. Usually marked with orange-colored lenticels. BUDS — Opposite, J-J of an inch long, covered with 2 rusty pubescent scales which enlarge into leaf-like bodies in spring when growth begins. Axillary buds 4 of an inch long, flattened, closely appressed to twig. Flower buds swollen near base. LEAVES — Opposite, simple, oval, 1-3 inches long, obtuse or slightly pointed at apex, usually wedge-shaped at base, finely serrate on margin, sometimes leathery when old, dark green above and pale green below; petioles usually round, rarely winged. LEAF-SCARS — See "Leaf -scars" under Sweet Viburnum. FLOWERS — Small, perfect, white, appearing about May in dense, many-flowered, sessile, and terminal cymes which are 3-4 inches broad. FRUIT — Fleshy, dark blue drupe which is persistent, sweet and rather juicy; contains a flat oval stone; grouped in few-fruited clusters borne on reddish stalks. WOOD — See "Wood" under Sweet Viburnum. DISTINGUISHING CHARACTERISTICS— The Black Haw, also known as Sweet Haw, Sheep- berry, Stag-bush, and Nanny-berry, closely resembles the Sweet Viburnum. See "Distinguishing Characteristics" under Sweet Viburnum. The Black Haw and the Sweet Viburnum may further be distinguished from the Maple-leaved Viburnum (Viburnum acerifolium) by the palmate vena- tion of the leaf-blade and the small gaping buds of the latter, and from the Arrowwood (Viburnum dentatum) by the coarsely dentate leaves, the small gaping buds, and the evidently- stalked flower clusters of the latter. RANGE — Connecticut, south to Georgia, and west to Arkansas. DISTRIBUTION IN PENNSYLVANIA— Common in the eastern and southern parts of the State, and local to sparse in the other parts. HABITAT — Prefers dry rocky hillsides. Sometimes found in rather moist locations. Fre- quent along fences and roadsides where seeds may have been dropped by birds. Often formg almost impenetrable thickets along fences, especially when coppiced. IMPORTANCE OF THE SPECIES — It is of no commercial importance as a wood-producing tree, but for ornamental purposes deserves to be planted extensively. The bark of the roots is valuable medicinally. 220 GLOSSARY. Abortion. Imperfect development or non-development of an organ. Abortive. That which is brought forth prematurely; coming to naught before it is completed. Achene. A small, hard, dry, 1-celled, 1-seeded fruit which does not open by valves. Acrid. Sharp or biting to the taste. Acuminate. Decidedly tapering at the end. Acute. Tapering at the end. Aesthetic. Pertaining to the beautiful. Afforesting. Turning ground into forest after being without a forest for a considerable length of time. Alluvial. Relating to the deposits of sand, clay, or gravel made by river action. Alternate. Not opposite to each other, but scattered singly along the axis. Ament, A peculiar, scaly, unisexual spike. Anther. The enlarged terminal part of a stamen which bears the pollen. Apex. The tip or end of a bud or leaf, i. e. the part opposite the base. Apical. Pertaining to the tip, end, or apex. Appresscd. Lying tight or close against. Arborescent. Tree-like in appearance, size, and growth. Aromatic. Fragrant ; with a pleasing odor. Astringent. Contracting; drawing, together ; binding. Axil. The upper angle formed by a leaf or branch with the stem. Axillary. Situate in an axil. Axis. The central line of an organ ; a stem. Bark. The outer covering of a trunk or branch. Basal. Pertaining to or situated at base. Berry. A fruit which is fleshy or pulpy throughout. Bisexual. Having both stamens and pistils, 1. e. male and female organs. Bloom. A powdery or somewhat waxy substance easily rubbed off. Bole. The body or stem of a tree. Boreal. Pertaining to the north. Bract. A modified leaf subtending a flower or belonging to an inflorescence. Bud-scales. Modified leaves covering a bud. Bundle-scars. Scars on the surface of a leaf-scar. Severed ends of the flbro-vascular bundles which connected the twigs with the leaves. Calyx. The outer portion of a flower, usually green in color. Cambial. Pertaining to the cambium. Cambium. A thin-walled formative tissue between the bark and wood. Capsule, A dry fruit composed of more than one carpel and splitting open at maturity. Carpel. A simple pistil or one member of a compound pistil. Catkin. An ament or spike of unisexual flowers. Chambered. Said of the pith when interrupted by hollow spaces at rather regular intervals.. Ciliate. Fringed with hairs on the margin. Coherent. Sticking together ; connected. Collateral. Accessory buds at the sides of axillary buds. Complete. Said of flowers when all parts are present. Compound. Composed of two or more similar parts united in a whole. Concentric. Said of growth rings when the growth center coincides with the geometrical center. Confluent. Flowing together ; uniting. Said of the bundle-scars when the separate ones flow together and appear as one. Conical. Cone-shaped. Conifers. A group of trees which usually produce their fruit in the form of a cone. Coniferous. Cone-bearing. Conniving. Brought close together. Contorted, Twisted together or back upon itself. Convergent. Tending to one point. Cordate. Heart-shaped. Corolla, The inner portion of perianth, composed of petals. The bright colored part of most flowers. Corymb. A flat-topped or convex flower cluster, blooming first at the edges. Corrugated. Shaped into grooves, folds, or wrinkles. Crown. The upper mass of branches, also known as head. Cyme. A flower cluster blooming from apex or middle first, usually somewhat flat. Cymose. In a cyme; cyme-like. Deciduous. Falling off, usually at the close of the season. Decurrent. Extending down the stem below the insertion. Defoliation. Removal of foliage. Dehiscent. Splitting open. Deliquescent. Said of the form of a tree with a broad spreading habit. The branches subdivide until they apparently disappear. Deltoid. Delta-like, triangular. Dentate. Toothed, usually with the teeth directed outwards. Diffuse-porous. Equal-pored. Said of wood when pores in a growth ring are equal In size. 221 Digitately-compound. With the members arising at the same point at the end or top of the support. Dioecious, Unisexual, with the two kinds of flowers on different plants. Disseminated. Scattered ; thrown broadcast. Divergent. Pointing away ; extending out. Said of buds which point away from the twigs. Downy, Covered with fine hairs. Drupe. A fleshy fruit with a pit or stone. Eccentric. Not circular. Said of growth rings when growth center does not coincide with geometrical center. Elongated. Long drawn out. Embryo. A young plant in a seed. Entire-margined. Margin smooth, not cut or roughened. Epidermis. The outer layer or covering of plants. Equidistant. Equal distances apart. Even-pinnate. With all the leaflets occurring in pairs. Excurrent. Said of a tree with a continuous trunk and erect habit of growth. Exfoliation. Splitting or cleaving off of outer layers of bark. Exotic. Of foreign origin. Exudation. Oozing out of sap, resin, or milk. Fascicle. A cluster, usually dense. Fertilization. The process by which pollen stimulates the ovule to produce a seed. Fetid. Ill-smelling. Fibro-vascular bundles. The conducting strands which connect the leaves with the stem. Fibrous. Consisting of fibers; woven in texture. Filament. The stalk bearing the anther. Fissures. Grooves, furrows, or channels as in the bark. Flora. The complete system of plants found in a given area. Fluted, Grooved, corrugated, channeled. Follicles. A dry fruit of one carpel, splitting on one side only. Forestry. The rational treatment of woodlands for their products. Fruit. A developing or ripened ovary. It may also include the axis containing the real fruit. Fungus. A plant devoid of green color such as mushrooms and rots. Gaping. With an open slit at the end or apex. Genus. A group of related species, as the pines or the oaks. Glabrous. Smooth, without hairs. Glandular. Bearing glands or gland-like. Glaucous. Covered with a bluish or whitish waxy coating; a bloom. Globose. Ball-like or nearly so. Globular. Ball-like. Habitat. The home of a plant. Head. A dense cluster of sessile flowers or the crown of a tree. Heartwood. The dead, central, usually highly colored portion of the trunk. Herbaceous. Herb-like, soft. Heterogeneous. Composed of dissimilar elements, as the wood of the hardwoods. Homogeneous. Composed of closely resembling elements, as the wood of the conifers. Imbricated. Overlapping like the slate on a roof. Incomplete. Said of flowers in which one of the outer parts is wanting. Increment, Growth ; increase. Indehiscent. Applied to fruits that do not split open to let out the seeds. Indigenous. Applied to plants that are native to a certain locality. Inflorescence. The flowering part of a plant, and especially its arrangement. Intolerant. Not shade enduring. Requiring sunlight. Involucre. A circle of bracts surrounding a flower or cluster of flowers. Irregular. Said of flowers showing inequality in the size, form, or union of similar parts. Keeled. With a central ridge, like the keel of a boat. Lamina. The blade or flattened portion of a leaf. Lanceolate. Shaped like a lance; several times longer than wide. Lateral, Situated on the side, as the buds along the side of the twig. Leaflets. One of the small blades or divisions of a compound leaf. Leaf-scars. The scar left, by the falling of a leaf. Lenticels. A corky growth on young or sometimes older bark which admits air to the interior of the twig or branch. Linear. Line-like, long and narrow, with parallel edges. Lobed. Said of leaves that have the margins more or less cut or divided. Lunate. Of the shape of a half-moon or crescent. Manna. A sweetish secretion used in medicine as a mild laxative. Medullary. Pertaining to the pith or medulla. Medullary Ray. Radial lines of tissues crossing the growth rings at right angles and extending Into the bark. Midrib. The central or main rib or vein of a leaf. Mongrel. Composed of two elements of entirely different origin. Monoe'cious. Bearing stamens and pistils in separate flowers on the same plant. Morphological. Pertaining to the form and structure of plants. Mucilaginous. Shiny, or gummy when chewed. NaJced. Said of buds without scales and seeds without a covering. Naval Stores. Refers to tar, turpentine, resin, etc. 222 Nerve. One of the lines or veins running through a leaf. Node. A place on a twig where one or more leaves originate. Non-porous. Without pores. Nut. A dry, 1-seeded, iudehiscent fruit with a hard covering. Nutlet. A small nut. 06-. A prefix meaning inverted or reversed. Oblique. Slanting, uneven. Oblong. About twice as long as wide, the sides nearly parallel. Obovatc. Reversed egg-shaped. Obtuse. Blunt. Odd-pinnate. With an odd or unpaired leaflet at the tip of the compound leaf. Opposite. Said of leaves and buds, directly across from each other. Orbicular. Circular-. Ovary. Tke part of the pistil producing the seed. Ovate. Egg-shaped. Ovoid. Egg-shaped or nearly so. Ovule. The body which after fertilization becomes the seed. Palmate. Hand-shaped; radiately divided. Panicle. A compound flower cluster, the lower branches of which are longest and bloom first. Parasite. Growing upon and obtaining its nourishment from some other plant. Parenchyma. A class of plant tissue found in the green layers of the bark, in wood and pith. Pedicel. The stalk of a single flower. Peduncle. The stalk of a flower cluster or «f a solitary flower. Pendulous. Hanging. Perennial. Last for more than one year. Perfect. A flower with both stamens and pistils. Perianth. A term applied to the calyx and corolla taken together. Persistent. Remaining after blooming, fruiting, or maturing. Petals. The part of a corolla, usually colored. Petiole. The stalk of a leaf.. Pinna. A division, part, or leaflet of a pinnate leaf. Pinnate. With leaflets on both sides of a stalk. Pistil. The central part of the flower containing the prospective seed. Pistillate. Bearing pistils but no stamens. Pith. The soft central part of a twig. Pod. Any dry and dehiscent fruit. Pollen. The dust-like substance found in the anthers of a flower. Pollination. The process of bringing the pollen of the male flower in contact with the stigma of the female flower. Polygamous. With both perfect and imperfect, staminate or pistillate, flowers. Pome. A fleshy fruit with a core, such as the apple. Prickle. A sharp-pointed, needle-like outgrowth. Profligate. Wasteful, extravagant. Propagative. Said of buds containing reproductive organs. Pseudo-. A prefix meaning false, not true. Pubescent. Hairy. Pungent. Ending in a sharp point; acrid. Pyramidal. Shaped like a pyramid with the broadest part near the base. Raceme. A simple inflorescence of flowers borne on pedicels of equal length and arranged on a common, elongated axis. Ray. See Medullary ray. Re flexed. Abruptly turned backward or downward. Reforestation. The process of putting a forest growth upon an area which had its forest growth removed recently. Regular. Said of flowers which are uniform in shape or structure. Resin-ducts. A passage for the conduction of resin found in the leaves and wood of the Pines. Ring-porous. Said of wood which has pores of unequal size, the larger ones being found in the spring wood and the smaller In the summer wood. Rugose. Wrinkled. Rugosities. Projections, wrinkles, knobs. Saccharine. Pertaining to or having the qualities of sugar. Samara. An indehiscent winged fruit. Sapwood. The recently formed, usually light wood, lying outside of the heartwood. Scales. The small, modified leaves which protects the growing-point of a bud or the part of a cone which bears the seeds. The small flakes into which the outer bark of a tree divides. Scurfy. Covered with small bran-like scales. Sepal. One of the parts of the calyx. Serrate. Having sharp teeth pointing forward. Sessile. Seated; without a fltalk. Sheath. A tubular envelope or covering. Shrub. A low woody growth which usually brandies near the base. Bilky. Covered with soft, straight, fine hairs. Simple. Consisting of one part, not compound. Sinus. The cleft or opening between two lobes. Species. A group of like individuals as Red Oak, White Oak, etc. Spike. An enlongated axis bearing sessile flowers. 223 Spile. A small peg or wooden pin. Sometimes synonymous with pile. Spine. A sharp woody outgrowth. Stamen. The part of a flower which bears the pollen. Staminate. Said of flowers which bear only stamens. Sometimes spoken of as male. Sterigmata. The projections from twigs bearing leaves. Sterile. Barren; unproductive. Stigma. The end of a pistil through which pollination takes place. Stipule. A leaf-appendage at the base of the leaf-stalk. Stipule-scar. The scar left by the fall of the stipule. Stoma. An opening in the epidermis of a leaf communicating with the internal air cavities. Striote. Marked with fine elongated ridges or lines. Striations. Long narrow lines or ridges. Strobile. A fruit marked by" overlapping scales as in the Pine, Birches, etc. Style. The 'pin-like portion of the pistil bearing the stigma. Sub-. A prefix meaning under or nearly. Sucker. A shoot arising from an underground bud. Superposed. Said of buds when they are arranged one above the other. Symmetrical. Regular as to the number of parts. Having the same number of parts in each circle. Terminal. Pertaining to buds located at the end of twigs. Thorn. A stiff, woody, sharp-pointed projection. Tolerant. Applied to trees which endure certain factors, particularly shade. Tomentum. A dense layer of hairs. Tomentose. Densely pubescent; hairy. Truncate. Ending abruptly, as if cut off at the end. Tubercle. A small tuber or tuber-like body. Tufted. Growing in clusters. Umbel. A flower-cluster with all the pedicels arising from the same point. Unisexual. Consisting of one sex only, either staminate or pistillate. Valvate. Said of buds in which the scales merely meet without overlapping. Vegetative. Said of buds which do not contain reproductive organs. Veins. Threads of fibro-vascular tissue in leaves or other organs. Versatile. Used for many purposes. Viscid. Glutinous; sticky. Whorl. A group of three or more similar organs, as leaves or buds, arranged about the same place of attachment. Whorled. Borne in a whorl. Zylology. The science which treats of the form and structure of wood. (224) INDEX. Page. Abies balsamen , 84 Abies Fraseri , 84 Acacia , 181 Three-thorned , 179 Acer, 190 Negundo , 197 • pennsylvauicum , 192 platanoides, 198 Pseudo-platauus , 198 rubrum , f)f> , f><> , 1 96 saccharinum , 195 saccharuiu 61 , 194 spicatum, 193 Aceraceae, 190 Aesculus: glabra, 200 octandni, 201 Hippocastanum , 200 Ailanthus, 38, 187 glandulosa , 187 Aider, , 38, 47, 48 Black, 39, 121 Smooth, 121 Alders, 45 Alnus rugosa, 121 Alternate-leaved Dogwood , 205 Amelanchier canadensis, ...' 174 Anacardiaceae, 182 Angelica Tree, 199 Anonaceae, 160 Apple, American Crab, 172 Aralia spinosa , 199 Arbor Vitae, 41, 86 Arrow-wood, 219 Ash, 22, 23, 47, 212 Basket, 215 Biltmore, 213 Black, 215 Brown, 215 Canadian , 214 Green, 213 Hoop, 215 Mountain, 48, 173 Page. Red, 216 White, 214 Ash-leaved Maple, 197 Asimina triloba, 160 Aspen, 38, 94 American, 96 Large-toothed , 97 Quaking, 96 Small-toothed , 96 Trembling, 96 Bairn of Gilead , 94 Balsam, 84 Basswood, 35, 38, 44, 48, 202 White, 203 Beaked Hazelnut, 122 Beaked Willow, 93 Bear Oak, 144 Bebb's Willow, 93 Beech, 30, 35, 39, 45, 49, 124, 125 American , 125 Blue, 120 European , 124 Water, 120 Beech family , 123 Bee-tree, 202 Benzoin aestivale, 161 Betula, \ .. 112 alba var. papyrifera, ..: 114 lenta, 118 lutea, 115 nigra, 116 populifolia , 117 Big Tree of Tule, ... 32 Big Trees, 33 Bignoniaceae, 211 Bignonia family, 211 Bilsted, 163 Birch: Black, 118 Canoe, 114 Cherry, 118 Gray, 115, 117 Oldfield, 117 15 (225) 226 Page. Paper, 36, 57, 114 Poplar, 117 Poverty, 117 Red, 116 River, 57, 116 Silver, 115 Sweet, 118 Yellow, 115 Birch family, Ill Birches, 30,31,38,44,45,47,48,112 Bladder Nut, 49 Bow-wood , 153 Box Elder, 197 Boxwood, 204 Buckeye: Big, 201 Fetid, 57, 200 Ohio, 200 Stinking, 200 Sweet, 57, 201 Yellow, 201 Buckeyes, 41 Butternut, 38, 102 Buttonball 175 Buttonwood, 31,34,35,39,47,175 Calico-bush, 207 Canoe Birch, 114 Caprifoliaceae, 218 Carolina Poplar, 99 Carpinus caroliniana , 120 Carya, 104 alba, 108 cordiformis, 110 glabra, 109 illinoensis, : 105 laciniosa, 107 microcarpa, 105 ovata, 106 Cashew family, 182 Castanea, 124 alnifolia, ..!:...,.... 124 dentata, .........;.. 126 pumila, ;..... 127 Catalpa, ; . . ... .38, 211 bignonioides, . . 211 Eastern, 211 Western, 211 Cedar: Coast White, 85 Red, 20, 57, 87 White, 36, 57, 85 Page. Celtis: crassifolia, 152 occidentalis, 152 Cercis canadensis, 180 Chamaecyparis thyoides, 85 Cherry : Appalachian, 165 Bird, 168 Black, 166 Cabinet, 160 Choke, 167 Domestic, 165 Fire, 168 Perfumed, 165 Pin, 168 Rum, 166 Sand, 165 Sour, 165 Sweet, 165 Wild, 166 Wild Black, 45, 166 Wild Red, 168 Chestnut, 20,23,27,30,31,33,38,40, 45,46,47,57.124,126 Chinquapin, 33, 127 Chionanthus virginica, 217 Cigar Tree, 211 Coffee Nut, 178 Coffee-tree, Kentucky, 178 Colorado Blue Spruce, 79 Cornaceae, 204 Cornel, Flowering, 204 Cornus: alternifolia, 205 florida, 204 Corylus: americana, 122 rostrata, 122 Cotton Tree, 99 Cottonwood, . . . ... . . . . . . . . . . . . :'. . . .94, 99 Black, ...;.;,...: 98 River, 98 Swamp, ;....... 98 Crab Apple, American, 172 Crack Willow, 89 Crataegus: coccinea, 171 Crus-galli, 170 Cucumber Tree, 157 Custard Apple family, 160 Cypress, Bald, 30 227 Page. Date-plum, 210 Deerwood, 119 Diospyros virginiana, 210 Dogwood, 44, 204 Alternate-leaved, 205 Blue, 205 Flowering, 204 Purple, 205 Ebenaceae, 210 Ebony family, 210 Elder, Elderberry , Common , 218 Elkwood, 158 Elm, 38 American , 151 English, 149 Gray, 151 Moose, 150 Red, 150 Slippery, 150 Water, 151 White, 151 Elms, 46, 47, 149 Ericaceae, 207 Evergreen Oaks, 128 Fagaceae, 123 Fagus: grandifolia, 125 sylvatica, 124 Filbert, 122 Fir, Balsam, 35, 84 Fire Cherry, 168 Firs, 31, 55 Fraxinus, 212 americana, 55,214 Biltmoreana, 213 excelsior, 212 nigra, 215 ornus, 212 pennsylvanica var. lanceolata, 213 pennsylvanica, 216 Fringe Tree, 217 Gleditsia triacanthos, 179 Great Laurel, 208 Gum: Black, 33,36,38,206 Red, 163 Sour, 206, 209 Sweet, 35, 163 Gymnocladus dioica, .., 178 Hackberry , 35,38,47,152 Hackmatack, 77 Hack-tree, 152 Page. Hamamelidaceae, 162 Hamamelis virginiana, 162 Haven-wood, 187 Haw, 170 Black, 219 Sweet, 219 Hawthorn, 170, 171 Scarlet, 171 Hazelnut, 45 American, 122 Beaked, 122 Common, 47 Heath family, 207 Hedge-tree, 153 Hemlock, 31,33,35,36,50,51,57,83 Carolina, 83 Ground, 67 Spruce, 83 Hercules' Club, 199 Hickory: Big Bud, 108 Big Shell-bark, 107 Bitter, 110 Bitter Nut, 110 Broom, 109 Mocker Nut, 108 Pecan, 105 Pignut, 109 Shag-bark, 36,106,107 Shell-bark, 106 Small-fruited, 105 Swamp, 110 White-heart, 108 Holly: American, 31,188 Deciduous, 31 European, 188 Large-leaved, 189 Mountain, 189 White, 188 Honey Locust, 38, 179 Honey Shucks, 179 Honeysuckle family, 218 Hop Hornbeam, American, ..44,45,49,119 Hornbeam, American, 120 Horse-chestnut, 200 Ilex: aquifolium, 188 monticola, 189 opaca, , 188 verticillata, 189 Indian Bean , 211 Ironwood, ..119, 120 . Page. Judas Tree, 180 Juglans, 101 cinerea , 102 j nigra, 103 regia, 101 Juglandaceae, 100 June Berry, 174 Juniper: Common, • .41,87 Dwarf, 87 Red, 87 Juniperus: communis, 87 virginiana , 87 Kalinia latifolia, 207 Kentucky Coffee-tree, 38, 41, 178 Larch, 30, 50, 55 American, 67, 77 Black, 77 European , 77 Larix: laricina , 77 decidua, 77 Lauraceae, 161 Laurel: Great, 208 Mountain, 31, 207 Laurel family , 161 Laurel Magnolia, 31, 57, 156 Leguminosae, 176 Leverwood , 119 Lime-tree, 202 Linden , 202 White, 203 Linden family, 202 Liquidambar, 163 styraciflua, 163 Liriodendron Tulipifera, 159 Live Oaks, 128 Locust: Black, 181 Common, 41,42,45,48,181 Honey, 38, 179 Sweet, 179 White, 181 Yellow, 181 Lombardy Poplar, 33, 94 Lynn, 202 Madura pomifera , 153 Magnolia, 38,41,44,57,155 acnmiuata , 157 Laurel, '. 31,57,156 Smnll, 156 Page. tripetala, 158 virginiana, 57, 156 Magnoliaceae, 155 Magnolia family, 155 Mahogany, 178 Maple: Ash-leaved , 197 Hard, 194 Mountain, 38,57,193 Norway, 198 Red, 38,56,57,196 River, 195 Rock, 194 Silver, 195 Soft, 195, 196 Striped, 38,39,45,192 Sugar, 38,60,61,194 Swamp, 196 Sycamore, 198 White, 195,196 Maple family, 190 Michaux Basswood , 202 Moosewood , 192 Morus: alba, 154 rubra , 154 Mulberry, 45, 47 Black, 154 Red, 154 White, 154 Nanuyberry, 218, 219 Nettle family, 47, 148 Nettle-tree, 152 Nicker Tree, 178 Ninebark, 164 Nyssa sylvatica, 206 Oak: Barren , 145 Bear, 56, 144 Black, 35, 142 Black Jack, 145 Bur, 134 Chestnut, 137 Chinquapin , 136, 138 Dwarf Chinq unpin , 138 Ground, 144 Iron, 133 Jack, 145, 146 Laurel, 146 Mossy-cup , 134 Over-cup, 134 Peach , 147 Pin, 33,34,35,140,147 229 Page. Post, 133 Red, 33,56,139 Rock, 40, 137 Scarlet, 141 Scrub, ........33,56,144 Scrub Chestnut, 138 Shingle, .. 146 Spanish , 143 Swamp , 140, 147 Swamp White, 135 Water, 140,146,147 White, 33,57,132 Willow, 147 Yellow, 136, 142 Oilnut, 102 Old Man's Beard, 217 Olea Europaea , 212 Oleaceae, 212 Olive family, 212 Olive Tree, 212 Osage Apple-tree, 153 Osage Orange, 47, 153 Osier, Green, 205 Ostrya virginiana, 119 Oxydendrum arboreum, 209 Papaw, 38,41,45,47,160 Paradise Tree, 187 Peach, 165 1'epperidge, 206 Persimmon, 50, 210 Physocarpus opulifolius, 164 Picea, 78 Abies, 79, 82 mariana, 81 pungens, 79 rubra , 80 Pigeon-berry , 205 Pinaceae, 55, 67 Pine: Austrian , 68 Jack, ; 55, 71 Jersey or Scrub, 33,57,75 Nigger, 55, 71 Norway, 72 Pitch, 20,55,71 Poverty, 73 Red, 22,55,57,72 Scotch, 68, 76 Pine: Short-leaf, 74 Table Mountain, ..57, 73 White, 20,22,31,32,33,48,55,70 Yellow, ...57, 74 Page . Pine family, 55, 67 Pinus: echinata, 74 laricio var. austriaca, 68 pungens, 73 resinosa, 55, 72 rigida, 55, 71 Strobus, 55, 70 sylvestris, 68, 76 virginiana, 75 Plane Tree, 175 Plane Tree family, 175 Platanaceae, 175 Platanus: occidentalis, 175 orientalis, 175 Plum: Porter's, 165, 169 Red, 169 Wild, 169 Wild Yellow, 169 Poison: Dogwood, 184 Elder, 184 Ivy, 182 Oak, ; 182,184 Sumach, 184 Poplar, '. 94,96,97 Balsam, 94 Birch, 117 Carolina , 99 Downy, 98 Lombardy, 33, 94 Silver-leaf , 94 Swamp, 98 White, 94 Yellow, 159 Popple, 96,97,159 Populus, 94 alba, 94 balsamifera, 94 candicans, 94 deltoides, 99 grandidentata , 97 heterophylla, 98 nigra var . italica , 94 tremuloides , 96 Primus, 165 alleghaniensis, 165 americana, 169 avium , 165 Cerasus , 165 .cuneata, 165 230 Page. Mahaleb, 165 Pennsylvania, 168 Persica, 165 pumila, 165 serotina, 166 virginiana , 167 Pulse family, 47, 176 Pussy Willow, 92 Pyrus: americana, 173 coronaria , 172 Quaking Aspen, 96 Quassia family, 187 Quercus, 128 alba, 55, 132 bicolor, 135 coccinea, 141 falcata, 143 ilicifolia, 56, 144 imbricaria, 146 macrocarpa, — 134 marylandica, 145 Muhlenbergii, 136 nana, 56 palustris, 140 phellos, 147 prinoides, 138 Prinus, 137 pumila, 56 rubra, 56, 139 stellata, 133 velutina, 142 Redbud, 180 Rhododendron, 31, 208 maximum, 208 Rhus: canadensis, 182 copallina, 186 Cotinus, 182 glabra, 182 Toxicodendron, 182 typhina, 185 Vernix, 184 Robinia Pseudo-Acacia, 181 Rosaceae, 164 Rose Bay, 208 Rose family, 164 Salicaceae, 88 Salix, 89 babylonica , 89 discolor, 92 fragilis, 89 lucida, 91 Page. nigra, 90 rostra ta , 93 Sambucus canadensis, 218 Sapindaceae, 200 Service, 174 Sassafrac, 161 Sassafras, 38,50,161 variifolium, 161 Savin, 87 Saxifrax, 161 Sequoia, 32, 33 Service Berry, 174 Shad Bush, 38,48,174 Sheepberry , , .£18,219 Simarubaceae, 187 Slippery Elm, 150 Smoke Tree, 182 Soapberry family, 200 Sorrel Tree, 209 Sour Gum, 206,209 Sour-wood, 209 Spanish Oak, 143 Spice Bush, 161 Spruce, 31,36,50,55,78 Black, 81 Colorado Blue, 79 European, 82 Norway, 22,79,82 Pine, 80, 83 Red, 80 Stag-bush, 219 Sugarberry, 152 Sumach, 38, 48 Dwarf, 186 Fragrant, 182 Mountain, 186 Poison, 184 Smooth, 182,185 Staghorn, 185 Swamp, 184 Velvet, 185 Sycamore, 175 Tamarack, 77 Taxaceae, 67 Taxus canadensis 67 Thorn Apple, 170 Newcastle, 170 Scarlet, 171 Tree, 179 Thuja occidentals, 86 231 Page. Tilia: • americaua , 202 heterophylla , 208 Michauxii, 202 Tiliaceae, 202 Tree of Heaven, 187 Tsuga: canadensis, 83 caroliniana , 83 Tulip Poplar, 159 Tulip Tree, 31,33,34,38,44,45,159 Tupelo, ; 206 Ulmus, 149 americana, 151 campestris, 149 fulva, 150 Umbrella Tree, 158 Urticaceae, 148 Viburnum: dentatum 219 Lentago, 218 Maple-leaved, 219 prunifolium , 219 Sweet, 218 Page. Walnut, 22,38,44,45,101,103 Black , .38,43,103 English, 101 White, 102 Walnut family, 100 Whistle- wood , 192 Whitewood, .159,202 Willow, 31,45,46,47,89 Beaked, 93 Bebb's, 93 Black, 90 Crack, 89 Glaucous, 92 Glossy, .'... 91 Oak, 147 Pussy, 92 Shining, 91 Weeping, 33, 89 Willow family, 88 Winterberry, 189 Witch-hazel, 45,48,162 Yellow-wood, 153 Yew, American, 67 (232) 876993 THE UNIVERSITY OF CALIFORNIA LIBRARY •••I •I 111