2 BULLETIN 878, IT. S. DEPARTMENT OF AGRICULTURE. 
SOUECES OF EXPERIMENTAL DATA. 2 
The experimental data have been obtained from three sources: 
Experiments conducted cooperatively by the Bureau of Plant Indus- 
try and the State agricultural experiment stations, experiments 
conducted independently by the Bureau of Plant Industry, and 
experiments conducted independently by the State agricultural 
experiment stations. 
The data from the following stations were obtained in cooperation 
with the State agricultural experiment stations : Williston and Dickin- 
son, N. Dak.; Havre and Moccasin, Mont.; Highmore and Newell, 
S. Dak.; and Sheridan and Archer, Wyo. At Newell, S. Dak., the 
station is operated by the Office of Western Irrigation Agriculture, 
and at Mandan, N N. Dak., Akron, Colo., and Sheridan, Wyo., the sta- 
tions are conducted by the Office of Dry-Land Agriculture, the Office 
of Cereal Investigations cooperating in the experiments with cereals. 
At North Platte, Nebr., the data were obtained independently by the 
Nebraska Agricultural Experiment Station. 
VARIETIES. 
Hundreds of varieties of wheat of foreign and domestic origin have 
been obtained by the United States Department of Agriculture. 
In prehminary nursery experiments most of these, however, have not 
proved adapted to this semiarid section. Those which have shown 
promise have been grown in plat experiments. The results of these 
experiments obtained in recent years are presented in this bulletin. 
The origin of the varieties is stated and, for convenience in presenting 
the experimental results, the varieties usually have been arranged in 
closely related groups. 
STRAINS OF COMMON AND DURUM WHEAT. 
All of the varieties of spring wheat which have shown promise in 
the northern Great Plains area belong to two main divisions or spe- 
cies — common wheat (Triticum vulgare) and durum wheat (Triticum 
durum) . As shown by the key, common wheat can be distinguished 
from durum wheat by the more slender spikes, by the shorter awns 
or absence of awns, by the looser spikes, by the spike being flattened 
parallel to the face of the spikelets, and by the smaller kernels. 
The origins of the principal varieties of both common and durum 
wheats are briefly given. Differences or similarities of closely related 
strains also are indicated. Heads of important commercial varieties 
of common and durum wheat are shown in Plate I, and grains of 
several of these varieties are shown in Plate II. 
2 The men who have been in charge of the cereal experiments at the various stations since 1913 are as 
follows: North Dakota.— Williston, F. R. Babcock; Dickinson, J. A. Clark and R. W. Smith; Mandan, 
J. C. Brinsmade, jr. Montana.— Havre, G. W. Morgan; Moccasin, N. C Donaldson and P. V. Cardon. 
South Dakota.— Highmore, J. D. Morrison and E. S. McFadden; Newell, S. C. Salmon, J. H. Martin, and 
A. D. Ellison. Wyoming.— Sheridan, L. D. Willey; Archer, J. W. Jones, V. H. Florell, and A. L. Nelson. 
Nebraska.— North Platte, L. L. Zook. Colorado— Akron, C. H. Clark, G. A. McMurdo, and F. A. Coffman. 
