pee SILVA OF NORTH AMERICA. 181 
Lake Champlain in Vermont, through western New England and New York, Pennsylvania west of the 
Alleghany Mountains, and the Atlantic states south of the Potomac River to western Florida, and 
westward to the base of the Rocky Mountains from southern Alberta to northern New Mexico. Com- 
paratively rare and of smaller size in the east and in the coast region of the south Atlantic and east 
Gulf states, the Cottonwood is the largest and one of the most abundant trees along all the streams 
between the Appalachian and the Rocky Mountains, marking their course over the mid-continental 
plateau to the extreme limit of tree growth, and growing to its largest size nearly to the one hundredth 
meridian. 
The wood of Populus deltoidea is light, soft, and not strong, although close-grained; it is dark 
brown, with thick nearly white sapwood, and contains numerous obscure medullary rays and minute 
scattered open ducts. The specific gravity of the absolutely dry wood is 0.3889, a cubic foot weighing 
24.24 pounds. Warping badly in drying and extremely difficult to season, it is now used only in the 
manufacture of paper-pulp, for cheap packing-cases, and for fuel. 
The Cottonwood, however, played an important part in the settlement of the prairie states west of 
the Missouri River before railroads joined the forests of the east with the western plains, furnishing the 
material for their first buildings from the rough stockade, raised to protect the struggling settler against 
the Indian, to the hotel and schoolhouse of the infant town. 
Populus deltoidea was probably introduced into Europe in the eighteenth century, and the first 
description of it was published in 1755 by Duhamel, who extolled its value for the decoration of parks.” 
It is still frequently planted in Europe, and no North American tree is more often seen there, the form 
with bright yellow leaves* especially. In the United States no other tree has been so generally planted 
on the plains and prairies east of the Rocky Mountains. Along the banks of streams in moist soil 
Cottonwoods have grown with remarkable rapidity and attained a large size, but in dry soil they soon 
begin to fall, and gradually disappear at the end of a few years, and without irrigation in regions of 
light and irregular rain-fall they have not proved successful.‘ 
With its massive pale stem, its great spreading limbs, and broad head of pendulous branches 
covered with fluttering leaves of the most brilliant green, Populus deltoidea® is one of the stateliest 
and most beautiful inhabitants of the forests of eastern America. 
1 Mason, Garden and Forest, iv. 182, f. 34. 5 Populus deltoidea is sometimes called the Carolina Poplar in 
2 Populus magna Virginiana, foliis amplissimis, ramis nervosis, European gardens, where it is also known as the Necklace Poplar 
quasi quadrangulis, Traité des Arbres, ii. 178 (excl. syn. Clayton). on account of the supposed resemblance of the elongated fruiting 
8 Populus Canadensis, d aurea, Dippel, Handb. Laubholzk. ii. 200. aments and their long-stemmed capsules to strings of beads. (See 
* Corbett, Garden and Forest, viii. 173.— Waugh, Garden and Loudon, Arb. Brit. iv. 1657.) In France it has long been known as 
Forest, viii. 502. le Peuplier suisse (Mathieu, Flore Forestiére, ed. 3, 439). 
