SHRUBS AND TREES. 127 



the kind above described, as it naturally assumes a parasol-like 

 top, grows rapidly, and dispenses with its bottom limbs quickly. 

 Being disposed to form crooked stems, some care must be 

 used in choosing straight-bodied thrifty nursery trees, and pro- 

 tecting the trunks until they are large enough not to need it. 

 Six thrifty trees will grow into a perfect canopy, of the size sug- 

 gested, within five years, if their central stems are cut back, and 

 kept to a height of about eight feet. For the next five years all 

 the upright growth at their tops should be annually cut back, so 

 that the trees will not exceed twelve feet in height. Afterwards 

 they may be allowed to grow naturally ; but their greatest beauty 

 will not be attained in less than fifteen or twenty years. 



Fig. 38 shows the ap- F ^ 



pearance they should make 

 in ten or twelve years after 

 planting. 



Next to the sassafras, 

 probably the judas or red- 

 bud trees, Cercis canadensis 

 and C. siliquastrum, form most 

 naturally into this kind of flat- 

 roofed bower. The White- 

 flowered dogwood, Cornus flori- 



da, is also adapted to the same use. Both spread lower than 

 the sassafras, but do not grow so rapidly when young. The 

 moose-wood or striped-barked maple, on the other hand, attains 

 the height required in a single season, and its green and yellow- 

 striped bark is ornamental. The branches, after the trunk has 

 attained the height of ten or fifteen feet, radiate naturally to form 

 a flat-arched head, and grow much slower than the first vigorous 

 growth of the stem would lead one to suppose. The foliage is large 

 and coarse, but the form of the tree is suited to the purpose under 

 consideration. Its large racemes of winged seeds, of a pinkish 

 color, are very showy in August. The paper mulberry is also a 

 valuable tree for such uses, and attains the required size and 

 density of head in less time than any of the others. The foliage is 

 unusually abundant and of a dark green color. 



