Trees of the Northern United States

Trees of the Northern United States, by A. C. Apgar, is a book on the study, description and determination of trees for the use of schools and private students. The preface says the book was prepared with the idea that teachers generally would be glad to introduce into their classes work dealing with the real objects of nature. The text explains that the central portion of the wood of many large stems is darker in color than the rest, that this darker portion is dead wood called heart-wood, and that the outer portion, called sap-wood, is used in carrying the sap during the growing season.

Species entries give size and form, as the entry for Great Laurel does with leaves thick, 4 to 10 in. long, elliptical-oblong or lance-oblong, and flowers white or slightly pinkish with yellowish dots. The text gives heart-wood colours by tree: very dark brown for the Walnut-tree, light red for the Cherry, and white and ivory-like for the Holly. A list of terms gives meanings, for example that Spatulate means gradually narrowed downward from a rounded tip.