266 TREES OF MINNESOTA. 
and smaller branches thick, smoother, but sharp angled or 
winged, at length becoming round. When the leaves unfold 
they are gummy and fragrant, with a balsamic odor, and covered 
more or less with white soft hairs; at maturity they are thick, 
leathery and green on both sides. Catkins pendulous; the 
staminate densely flowered and from three to four inches in 
length and a half inch in thickness; the pistillate sparsely flow- 
ered, thin stemmed and often a foot long before the ripening of 
the seeds. Stamens sixty or more to each flower. Seed oblong, 
one-twelfth of an inch in length, and surrounded by a tuft of 
long hairs, which aid in its distribution. Tree sometimes 100 
feet high, with trunk occasionally seven or eight feet in diameter. 
Distribution —From Quebec south to Florida and west to the 
base of the Rocky Mountains, from Alberta to New Mexico 
along banks of streams, where it often forms extensive groves. 
In Minnesota common in the southern part of the state, but rare 
farther north. 
Propagation.—By seeds and by cuttings. Seedlings can be 
obtained in large quantities on the sand bars along our rivers and 
on shores of receding lakes, and this is the chief source of sup- 
ply. The opinion is common that seedlings are longer lived than 
plants from cuttings. 
Propertics of 1’ood.—Light, soft, spongy and weak, although 
close grained; dark brown, with thick nearly white sapwood. 
Specific gravity, 0.3880; weight of a cubic foot, 24.24 pounds. 
Uses.—The Cottonwood has been largely used in the Western 
States for timber and fuel. as a shade tree and for windbreaks. 
For all these purposes it is a very inferior tree, but on account 
of its abundance, rapid growth and hardiness it has almost neces- 
sarily been largely used in the pioneer work of settlement. As 
a timber tree it is inferior on account of its timber warping 
badly in drying and being extremely difficult to season. As a 
tree for shade and windbreaks it is not so valuable as the Green 
Ash, White Willow, White Elm or Boxelder; on the dry prairie 
it is subject to leaf rust, is short-lived, and fails to make a shade 
dense enough to keep the grass out of groves. The pistillate 
form is objectionable on account of the cottony floats with which 
it fills the air when shedding its seed. It has, however, done 
good service in our Western States, and may continue to be of 
