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experimentation to determine the adaptability of species to the climate; 
the settlement of the country being recent, comparatively little plant- 
ing has been done. Oklahoma, Kansas, southern Nebraska, and 
southern Colorado should beable to grow a larger variety of trees than 
the more northern States: Russian Mulberry, Silver Maple, Hackberry, 
Black Locust, Honey Locust, White Elm, Catalpa, Black Cherry, 
Cottonwood, Aspen (especially in the West) Black Walnut, Bur Oak 
(Quercus macrocarpa), Red Oak (Q. rubra), Chinguapin Oak (Q. acumi- 
nata), Green Ash, White Ash, Red Cedar, Rock Pine, and possibly White 
Fir and Douglas Spruce, with Scotch and Austrian Pine for the more 
northern part of the region. In addition to these a number of other 
species are doubtless worthy of trial, but only such are mentioned here 
as are available by purchase or by collection within the region named. 
From central Nebraska northward the colder temperature will pre- 
vent the use of several species of the above list, notably Russian Mul- 
berry, Black Locust, Catalpa, and Chinquapin Oak, and north of the 
Towa line Black Walnut and Honey Locust. In the northern region, 
however, the Birches and Spruces are added to the list. In the ex- 
treme north a very few species are available, the principal ones being 
Boxelder, Aspen, Yellow Birch, Sweet Birch, White Elm, Red Cedar, 
White Spruce, Red Pine, Jack Pine, Scotch Pine, and Austrian Pine. 
In addition to these trees there are several shrubs and small-sized 
trees that may prove very useful in Western planting. Among these 
may be named Artemisia abrotanum tobolskianum, a Russian sage brush 
that has proven a hardy and very vigorous grower from Kansas to the 
Northwest Provinces of Canada. It attains a height of 6 feet the first 
season, and makes a useful hedge for catching snow. One year’s trial 
was sufficient to demonstrate its unfitness for use in great quantity as 
a nurse in close planting, but in wider planting it may perform the 
office of soil-cover well, and as a wind barrier and snow catcher it will 
afford great and needed protection when placed to windward of a plan- 
tation. Other east Russian species that give evidence of hardiness 
and vigor are Hlewagnus angustifolia and Tamarix amurensis. The Rus- 
sian Poplars, which were imported several years ago and which are 
quite hardy, seem not to be able to resist the heavy droughts that occur 
in the Northwest. They may prove useful for planting near streams 
and in moist soil, but for this purpose there are native species of greater 
value. 
The Yearbook of the Department for 1897 contains a list of economic 
trees suitable for planting in various parts of the country, and this 
will be found helpful in adding to the varieties above mentioned. 
INTRODUCTION OF EXOTIC TREES. 
It has been frequently asserted that native trees are better adapted 
to the conditions of the country in which they occur than those imported 
from other countries. While experience shows that this is not even 
