UNITED STATES DEPARTMENT OF AGRICULTURE 
BULLETIN No. 1074 
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, Cerealist in Charge, Office of Cereal Investigations, 
Bureau of Plant Industry 
CONTENTS 
Page 
Necessity for a Classification of Wlieat . 1 
Previous Investigations 2 
Foreign -Classifications 3 
American Classifications 7 
Sammary of Previous Classifications . 9 
Present 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 Subspecies . . 50 
Common Wheat 50 
Club Wheat 172 
Poulard Wheat 180 
Durum Wheat 183 
Emmer 193 
Spelt 195 
Polish Wheat 197 
Einkom 198 
Unidentified Varieties 199 
Estimated Acreage of Varieties 207 
Literature Cited 219 
Index to Varieties and Synonyms . . . .231 
WASHINGTON 
GOVERNMENT PRINTING OFFICE 
1922 
