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 350 

 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 meas- 

 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. Rothrock 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 w^hich 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 



