4 BULLETIN 24, U. S.. DEPARTMENT OF AGRICULTURE. 
the difference in the tree—pointing out that the “ white cottonwood ” 
has a closer, thinner bark of darker color than the thick, rough, gray- 
ish bark of the “ yellow cottonwood.” There seems to be no doubt, 
however, that both the white and the yellow varieties come from the 
same species. 
The yellow cottonwood is not only darker in color, but is said to 
work more easily and be less subject to warping. It is probably the 
wood of the older trees. The white cottonwood appears to come 
usually from comparatively young trees of rapid growth, which, how- 
ever, may be as large as older, slower-growing individuals. Yet white 
cottonwood lumber is by no means typical of the younger stands, 
which usually saw out wood of excellent quality. 
USES. 
Cottonwood has a wide range of uses, and for certain purposes is 
being used in place of much more costly woods, such as white pine 
and yellow poplar. It was for a time marketed as “ sap poplar,” 
but was soon accepted by the wood-using industries under its true 
name. ; 
In the manufacture of shipping cases for food products cottonwood 
is used in large quantities. When properly seasoned it imparts little 
if any taste or odor to the contained product. For this reason also 
it is in demand for candy pails and the like. Its toughness and 
lightness give cottonwood additional fitness for boxes and crates. 
Experiments by the Forest Service? to determine the comparative 
strength of packing boxes of various woods demonstrated beyond 
question that, when taken weight for weight, the cottonwood box 
outclasses in strength similar containers of: practically all other 
species extensively used—such as white pine, yellow pine, spruce, 
hemlock, and red gum. Bulk for bulk, cottonwood is surpassed only 
by red gum. 
A large amount of cottonwood is manufactured into rotary veneer, 
which is employed for a wide variety of purposes, cores or filling of — 
built-up lumber, panels, bottoms, sides and backs of drawers, light- 
weight veneer boxes, cases, egg crates, baskets, and trunks. Such 
veneer opens up a large field of uses for cottonwood from which it 
would otherwise be excluded because of its hability to warp. Three- 
ply veneer three-eighths of an inch thick is much stronger than solid 
wood five-eighths of an inch thick. Considerable cottonwood veneer, 
3 to 5 ply, is exported to Europe for backing upon which to lay more 
costly woods in the manufacture of musical instruments, cases, and 
furniture. 
Since cottonwood in close stands early clears itself of preueee 
select logs cut out a fairly high percentage of clear and upper grades 
1 Forest Service Circular 47, ‘‘ Tests of Packing Boxes of Various Woods.” 
