DECIDUOUS TREES. 361 



poplars — a character that unsuits it for small grounds, and adapts 

 It to large spaces where it is desirable to have a quick, lofty growth 

 of trees. For some reason, however, the best English gardeners 

 prefer the black Italian poplar for the same purpose — a variety or 

 species supposed to be a cross between this species and the black 

 poplar of Europe. 



This tree has been appropriately named cottonwood from the 

 quantity of cotton enveloping its seeds, which in May becomes 

 detached and floats ni the air in such quantities where the tree 

 abounds as to be a great nuisance at that season. 



In Its early growth the cottonwood is simply rank, upright, and 

 uninteresting ; but after it has reached fifty or sixty feet in height, 

 Its branches begin to bend gracefully, the foliage breaks into fine 

 rounded masses, and it spreads into a park tree of noble propor- 

 tions. It should never be planted near dwellings or in streets. 



The Black Poplar, P. nigra, of England, is said to resemble 

 our cottonwood in most respects. 



The Black Italian Poplar. P. inonilifera. — It is in doubt 

 whether this is, or is not. a native of America. The fact that 

 neither of the indefatigable Michaux found it wild in America, and 

 that its characteristics unite those of the cottonwood and some of 

 the European, poplars, makes it probable that it is a hybrid between 

 them. In form and vigor of growth it is like the cottonwood. An 

 English specimen is recorded as having attained the height of 

 ninety feet twenty-five years after planting ! This in Worcester- 

 shire. At the Syon Park, England, there is a tree of this species 

 one hundred and two feet high, and about one hundred feet in 

 breadth of head. 



The Balm of Gilead Poplar. Populus candicajis. — This is a 

 tree of great vigor of growth, with large conspicuous buds covered 

 with balsamic gum. The leaves are nearly heart-shaped, from five 

 to eight inches long, glossy on the upper surface, and downy be- 

 neath. The form of the head when young is pyramidal, more com- 

 pact than that of the cottonwood, and becomes a spreading tree of 

 less height. The leaves appear two weeks later than those of our 

 native aspen. 



