UNITED STATES DEPARTMENT OF AGRICULTURE 
BULLETIN No. 1074 ^ 
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Washington, D. C. 
PROFESSIONAL PAPER 
November 8, 1922 
CLASSIFICATION OF AMERICAN WHEAT 
VARIETIES. 
By J. Allen Clark, Agronomist in Charge. John H. Martin, Agronomist, 
Western Wheat Investigations, and Carleton R. Ball, Cei-ealist in Charge, 
Office of Cereal Investigations, Bureau of Plant Industry. 
CONTENTS. 
Page. 
Necessity for a classification of wheat_ ] 
Previous investigations 2 
Foreign classifications 3 
American classifications 7 
Summary of previous classifica- 
tions 9 
Tresent investigations 10 
Classification nurseries 11 
Preparing descriptions, histories, 
and distributions 15 
Varietal nomenclature 17 
The wheat plant 22 
Morphological characters 23 
Physiological characters 47 
Page. 
Classification of the genus Triticum_ 48 
Key to the species or oubspecies- 50 
Common wheat 50 
Club wheat 172 
Poulard wheat I8O 
Durum wheat i83 
Emmer 193 
Spelt 195 
Polish wheat 197 
Einkorn i9g 
Unidentified varieties 199. 
Estimated acreage of varieties 207 
Literature cited 219 
Index to varieties and synonyms 231 
NECESSITY FOR A CLASSIFICATION OF WHEAT. 
The varieties of wheat grov^n in the United States show a great 
diversity of type. This diversity is natural, as wheat is produced 
commercially in all of the 48 States of the Union, under a wide rano-e 
of environmental conditions. More than 200 distinct varieties are 
grown. Many of these are adapted only locally, while others are 
well adapted to a wide range of varying conditions. This adapta- 
tion of a variety is an important factor, as it affects the yield and 
profitableness of the crop. The choice of varieties for given condi- 
tions and purposes, therefore, usually is given careful consideration 
by growers. The choice, however, is dependent upon the determina- 
tion of identity. 
95539' 
-Bull. 1074- 
