PLANT LIFE IN OKLAHOMA. 57 



for shade in our cities. Cottonwood may also be added to the list. The 

 chief reason for selecting most of these treesi is that they are quick 

 growing. The locust if used will have to be safeguarded against the locust 

 borers "which have wrought such great havoo in other states; the catalpai 

 against the catalpa, sphinx. The Cottonwood, while a very rapid grower, 

 has its faults. It sheds leaves continually through the summer and 

 becomes bare in early fall, and the roots find their way into wells 

 -and sewers and do much damage. In many eastern cities ordinances 

 have been passed requiring all cottonwoods within 100 feet of sewers 

 to 'b« cut. The walnut, red bud and oaks may also be added to 

 the list for shade. In Oklahoma City many oaks and cottonwoods of 

 the original forest still stand for shade. Among imported trees suitable 

 for street and lawn planting are the dwarf catalpa, linden, tree of Heaven, 

 Paulounia, and Koelreuteria paniculata, a native of China. Fruit trees 

 may also be used for shade even for planting along streets and roadways. 

 People will soon learn to respect the trees and they will not be abused in 

 securing the fruit. 



Trees have two distinct modes of branching — one has a central stem 

 running the entire length of the tree as in the hickory or pine. This is 

 called the excurrent growth. In the second class the main stem is soon 

 lost in the branches as in the walnut or catalpa. This is known as 

 delinquescent growth. Two kinds of roots are found on trees — those 

 having a tap root as in the liickory and oaks. These trees are difficult to 

 transplant. Those having multiple roots in which the roots are numerous 

 and extend outward from the base, as in the maples and elms. Such trees 

 are easily transplanted. 



Willows and poplars may be started by branches placed in the 

 ground. Most trees are best grown from the seed. Trees best for trans- 

 planting are those not more than two years old. 



