The habitat of many species is discussed; which suggests forestal, horticultural and ornamental possibilities. Then too, the habitat of a tree, helps to identify it. When associated trees are given, those are enumerated which are characteristic of the species throughout its range in our area and they are arranged in the order of their abundance.
A county map of the State is included which will assist in finding the range of each species. A forestal area map is also added to visualize certain habitats of the State.
The range and distribution of the species in the State has been given considerable attention to encourage investigation along this line.
Remarks.—Under this title the economic uses of the trees and their products have been given. In addition horticultural and unclassified information is included.
Illustrations.—All of the illustrations except two are photographic reproductions of specimens in the writer's herbarium. The two drawings were used in the first edition.
About 20 of the photographs were made by Paul Ulman, and the remainder by Harry F. Dietz, who has laboriously tried to obtain good reproductions from the material at hand.
Explanation of Map of Certain Forestal Areas.—In describing the distribution of certain species of trees within the State, it was found convenient to speak of certain forestal areas which are here described, and are illustrated by a map which may be found at the end of the text.
Lake Region:—The southernmost lakes in Indiana are those located in the southwestern part of Wells County; Lake Galacia about five miles northeast of Fairmount in Grant County; Lake Cicott in Cass County; and Kate's Pond about 11/2 miles northwest of Independence in Warren County. Roughly estimated, all of Indiana north of a line connecting these lakes might be considered the lake area of the State. Prairie Area:—While the interior of Indiana has quite a few small areas called prairies, the real western prairie did not extend far into the State. The dividing line is very irregular, and several elongated lobes extended farther east than indicated by the map. The larger areas east of the line were the extensive prairie area of the Kankakee Valley; the northern part of Pulaski County; and parts of White and Tippecanoe Counties. "Knob" Area:—This is the hilliest part of the State and is located in the southcentral part. It is contained in the unglaciated portion of the State, and includes the "knobs" of the Knobstone, Chester and Mansfield sandstone areas of Indiana. In this area are included the scrub pine and chestnut oak, with one exception; sorrel tree and the chestnut, with two possible exceptions. The Flats:—This is a level stretch of country, here and there deeply eroded. Being level, and the soil a fine compact clay, the drainage is poor which suggested the local name "flats." The Lower Wabash Valley:—This is part of Knox, Gibson and Posey Counties which is usually inundated each year by the Wabash River.
Acknowledgments.—The character and qualities of the wood have for the greater part been taken from the works of Britton and Brown, Hough, and Sargent, to whom indebtedness is acknowledged.
The Salicaceæ, except the genus Populus was written by C. R. Ball, of the Bureau of Plant Industry, Washington, D. C. The Malaceæ was contributed by W. W. Eggleston, also of the Bureau of Plant Industry, Washington, D. C. These authors were asked to make their part conform to the general plan of the book. Mr. Ball and Mr. Eggleston are recognized authorities on the respective parts they have written and users of this book will appreciate the value of having these difficult parts written by our best authorities. The author wishes to gratefully acknowledge this great favor.