FOREST TREES OF THE UNITED STATES.

CENTENNIAL COLLECTION.

SIR: The following list is a catalogue of the native and naturalized forest trees of the United States which attain a height of 16 feet and upward. Descriptive notes of many species are appended.

By an act of the last Congress an appropriation was made to enable the different Departments of the Government to participate in the International Exhibition of 1876. In pursuance of this object, the Department of Agriculture undertook to make a collection to represent the trees of the United States. The aim was to represent every important tree by botanical specimens of the leaves, flowers, and fruit, and also by sections of the trunk, showing the appearance of the bark and of the wood; thus giving the completest possible view of every species. The great extent of our country and the immense variety of our arborescent vegetation made this of necessity a great undertaking. Well knowing that the chief value of such a collection would depend upon its scientific accuracy, arrangements were made to engage competent persons in the different fields of labor. In some portions of the country, local botanists were employed to collect the trees of their particular districts. But for the larger portion of the country it was neces sary to employ traveling agents, whose duty it was to explore a desig nated section, ascertain the localities of the trees desired, collect the proper botanical specimens at the right season, and, having carefully noted the localities, to return at the end of the growing period and obtain sections of the trees.

As collector for the Southern States, Mr. A. H. Curtiss, of Liberty, Va., a well-known botanist, was engaged.

A large number of the trees of the Middle States were obtained in the vicinity of Washington. Of these, thirty species were procured from a part of the General Washington estate at Mount Vernon, now owned by Dr. E. P. Howland.

The trees peculiar to the New England States were procured by Mr. C. G. Pringle, of Charlotte, Vt.

As collector for the Western States, Mr. John Wolf, of Canton, Ill., was employed. In making the collection in Colorado, he was assisted by Mr. C. W. Derry, of Granite, Lake County, Colorado.

The semi-tropical trees of Southern Florida were obtained by Dr. A. W. Chapman, of Apalachicola, during a two months' cruise by schooner

on the west coast, among the various keys and inlets, and far into the interior by the Caloosahatchee River. Dr. Chapman is an old resident of Florida, author of the "Flora of the Southern States," and better acquainted with the vegetation of that region than any other person.

A portion of the trees of Texas were obtained by Dr. S. B. Buckley, of Austin, whose labors in developing the botany of that section are well known; and a portion were collected by Dr. F. G. Lindheimer, a veteran botanist, whose collections of Texas plants, made many years ago, enrich the principal herbaria of the country.

In Utah, Mr. L. F. Ward, botanist of the survey of the Colorado River by Messrs. Powell and Thompson, made the collection of the trees of that region.

The trees of the high sierras of California and Nevada were procured by Mr. J. G. Lemmon, of Sierra County, California. The magnificent conifers of that region are represented by large wedge-shaped sections of trees from 4 to 7 feet in diameter, the preparation of which cost a great amount of toil and expense. The immense trees had to be felled, and the desired sections removed by sawing and splitting with wedges until the portions were reduced to proper size.

The trees of the Pacific slope in California were collected by Mr. G. R. Vasey, with valuable aid and assistance from Dr. A. Kellogg, of San Francisco, Dr. J. G. Cooper, and others.

Dr. Edward Palmer made the collection for the southern portion of California, Arizona, and Southern Utah.

Mr. A. J. Dufur, Centennial Commissioner for Oregon, collected the peculiar trees of that State.

After the woods were received at Washington, they were taken to a mill and reduced to the uniform length of two feet; then each section was divided by sawing longitudinally into two pieces, which were planed on the sawed surface, one arranged to show the outer or bark surface and the other to show the grain of the wood, its color, density, &c.

The corresponding botanical specimens for each species are displayed in frames arranged in the immediate vicinity of the trees to which they belong. By this means, an intelligent view of the appearance and properties of every species of the trees of the country may be obtained.

Great difficulty was experienced in deciding upon the limitations of height and size which should characterize a tree. It is well known that certain plants which are only shrubs in some places become large trees in other places; sometimes the difference depending on climate and sometimes on other circumstances. Thus, Magnolia glauca, or White Bay, grows and matures its flowers and fruit in some portions of Massachusetts where it attains only the size of a large shrub. It, however, steadily increases in size in situations farther south, until in Georgia and Florida it attains the size of a large tree. In some places, the same plant appears as a shrub or a tree, under different circumstances, in closely contiguous localities. Dr. Chapman, who made the collection of

the trees of South Florida, says: "I was much disappointed in the size of most of the forest growth in that region. A peculiarity of these tropical trees is, that for miles they occur to you as mere shrubs, when at some other locality you find them lofty trees." As a general rule, I have not admitted into the collection any tree which does not, under favorable circumstances, attain a height of 20 feet and a diameter of 4 inches. Yet, in a few cases, in order the more fully to illustrate a family, a tree has been admitted which would fall below that standard. The accompanying catalogue enumerates about 400 species, the greater portion of which are represented by specimens in the collection.

Some portions of the country have been so incompletely explored that our knowledge of their vegetation is imperfect; yet it is probable that this catalogue presents, with great accuracy, our present knowledge of the trees of the United States. In two or three instances only, foreigu species have been admitted, because of their extensive naturalization in some sections.

The two largest genera of trees are the oaks and the pines, of which we have about 30 species of each. Of coniferous trees, including the Pines, Firs, Cedars, Larches, Cypresses, Sequoias, &c., we have about 60 species. The Rose family, including the Plums, Cherries, Thorns, &c., is represented by over 30 species. Of the order Leguminosa, or trees of the pod-bearing family, we have over 20, embracing the Locusts, Acacias, Redbuds, Mesquits, &c. Of Ericaceous trees we have 8 species, including the Californian Manzanita and Madrone trees, the Sorrel tree of the Southern States, and others. Of Maples we have 8; of Magnolias, 7; of Ash, 11; of Elms, 6; of Walnuts and Hickories, 13; of Poplars, 8; and of Birch, 6 species.

The usual difficulty has been encountered of deciding as to the standing of certain forms which some botanists regard as species and others as only varieties. In most well-marked cases, these are entered in the catalogue under distinct numbers, either as species or as varieties, as the evidences in the case seemed most convincing.

The range, or botanical region, of each species is indicated in a general manner, thus: Those trees which occur more or less extensively over the whole or the larger portion of the country cast of the base of the Rocky Mountains or east of the Mississippi River are marked Eastern United States. This region is subdivided, by a line running eastward from the mouth of the Ohio River to the Atlantic, into two portions, one of which is called Northeastern United States, and the other Southeastern United States. Other localities are indicated as Southern States, New England States, Western States, Alleghany Mountains, &c. The western portion of the United States and Territories is marked in detached regions, as follows: Rocky Mountains of Colorado, or Rocky Mountains of Colorado and Utah; Sierra Nevada Mountains of California, Oregon, and Washington Territory; California; Southern California; Arizona. The por25 CEN, PT 2

tion of the country adjoining the Mexican border is indicated by the locality Western Texas and westward.

Certain portions of our country have not yet been sufficiently explored to determine accurately all the species of trees thereto belonging. This is the case with respect to the southern portion of Florida. Some species which at one time were thought to be indigenous in that region have not been confirmed by any late investigations, and will probably have to be erased from our list. The same difficulty occurs with respect to some of the trees of the Rocky Mountains and the western coast, particularly the Conifers and the Willows.

In the short time allotted to making this collection, it has not been possible to obtain wood specimens of every species given in the catalogue. The number wanting, however, is but a small percentage of the whole.

Among the good results growing out of this work, we may mention, first, that much information has been gained respecting species hitherto imperfectly known; and, secondly, that four or five new species, or species before unknown to our flora, have been obtained. These are mainly in South Florida, and include two exogens, viz, an Anona or Custard Apple, and a Chrysophyllum or Star Apple; and one endogen, a Palm of the genus Thrinax.

I wish to record my sincere thanks to the Hon. F. Watts, Commissioner, and to Mr. William Saunders, Representative of the Department at the Exhibition, for all possible assistance rendered in the prosecution of the work.

No. 1. Magnolia grandiflora, L.-Evergreen Magnolia.-Southern A large and beautiful tree, with thick glossy evergreen leaves,

and large white flowers, which are exceedingly fragrant.

No. 2. Magnolia glauca, L.-Sweet Bay; White Bay.-Massachusetts southward. Northward, this is only a small tree or shrub; but in the South it attains a large size, and the leaves become evergreen.

No. 3. Magnolia umbrella, Lam.-Umbrella Tree.-Southern States; Alleghany Mountains.

No. 4. Magnolia acuminata, L.-Cucumber Tree.-New York; South and West. This species has a greater range to the northward, where it sometimes attains a large size.

No. 5. Magnolia cordata, Michx.-Yellow Cucumber Tree.-Southern States.