THE STRUCTURE AND FUNCTION OF HIGHER PLANTS 79 



to the dark green of the white pines and the hemlocks; such contrasts 

 make the colors appear all the more striking. This is especially true in 

 New England, \\here the '-'murmuring pines and the hemlocks" are so 

 wide-spread. The aspen leaves also add their touch of flickering yellow, 

 while the waxy barks of the white birches presage the snows that lie in 

 store. 



The rolling hills and ancient mountains of our northeastern states form 

 a perfect setting, so that the trees for miles around may be seen at a glance 

 — as if to make it easy for us to enjoy the sight. The hills and valleys and 

 lakes and streams also offer a variety of conditions — of soil, of moisture 

 and even of temperature, and so are important in producing diversity and 

 intensity of color in plants growing close together, even in plants of the 

 same species. 



South of New England the center of the stage is held not by the sugar 

 maple, but by the oaks. The warm reds and reddish browns are furnished 

 mostly by these trees. Each species of oak adds its own touch to the general 

 pattern. By far the most brilliant is the scarlet oak, which amply justifies 

 its name in the fall. Not a striking tree otherwise, the scarlet oak passes 

 unnoticed until it takes on its cloak of autumn, and then it stands out like 

 one whose modest virtues have been unappreciated. There is a whole 

 galaxy of oaks in eastern North America, each of which typically ripens 

 into a color that is largely its own. The white oak, whose staunch timbers 

 have been used so extensively in shipbuilding, often has leaves red above 

 and white underneath. When they blow in the breeze, the tree presents a 

 curiously changing color pattern. Pin oak may assume an orange-brown 

 color; chestnut oak becomes a bright yellow; black-jack oak may be 

 brownish red, but more often is a glossy light brown, suggesting the leather 

 of new riding boots; red oak passes from green to yellow to brown, while 

 black oak soon becomes a dull brown. In spite of all these variations in the 

 oaks, and in spite of the brilliance of their coloration, compared with the 

 sugar maple there is a slight touch of the sombre in their effects. 



While the maples and oaks form the theme of this symphony, the varia- 

 tions are provided by many of our other trees. Dogwood, white or pink 

 at blossom time in the spring, is just as pleasing in the fall, with its red 

 leaves and red fruits; and dogwoods are found from Maine to Florida 

 and west to Texas. Along the banks of streams, and in low ground gen- 

 erally, the sour gum and sweet gum are often seen. These may also be red, 

 or they may be clothed in royal purple. Sour gum is one of the first trees 

 to turn in the fall — a harbinger of the great display to come. White ash 

 may be yellow, or it is sometimes reddish or bluish purple. Sassafras, whose 

 roots are sometimes brewed into a tea, especially in the spring, and served 

 (under protest) to children, adds its tone of bright orange to the drier 

 hillsides. Like the dogwood, it is widely distributed in eastern North 

 America. 



