16 BULLETIN 816, U. S. DEPARTMENT OF AGRICULTURE. 
valuable as those already demonstrated to be valuable over large 
areas. ‘Those mentioned have all been tested in a small way. 
Caution should be used in selecting trees with conspicuous flowers 
and those with edible fruits or nuts, as in many parts of the country 
such trees are badly mutilated by the public. Even horse-chestnuts, 
Ithough the nuts are not edible, are often broken by boys clubbing. 
the trees. That public opinion can prevent such vandalism is in evi- 
P15394HP 
Fic. 16.—Live oaks, the handsomest southern street tree for broad streets. Biloxi, Miss.; late summer. 
dence all along the Pacific coast and at a few places in the East. 
Every effort should be made to create a sentiment that will protect 
these attractive additions to street adornment, but where the senti- 
ment does not exist it is better to avoid the planting of such trees 
except in a limited way. 
Besides the native trees there are many introduced trees that have 
proved valuable and many more that are worthy of trial.t A fair 
trial of promising introduced trees should be made, and the native 
kinds should be thoroughly tested. 
TREES FOR DIFFERENT REGIONS. 
To simplify the discussion of kinds of street trees likely to prove 
satisfactory, the United States has been arbitrarily divided into the 
regions shown in figure 17. An endeavor has been made to make 
each division cover an area haying similar growing conditions, so that 
the trees suggested will be likely to thrive in all its parts. A dis- 
1 As examples of this are a number of new elms such as Ulmus pumila and Ulmus densa, besides lindens, 
poplars, and Koelreuteria paniculata, while Pistacia chinensis is suitable for warm regions. The Office 
of Foreign Seed and Plant Introduction of the United States Department of Agriculture will be glad at 
any time to suggest new trees that are promising for any region. 
