UNITED STATES DEPARTMENT OF AGRICULTURE 



BULLETIN No. 1074 



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Washington, D. C. 



Issued November 8, 1922; revised August, 1923 



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 wheat- 1 



Previous investigations 2 



Foreign classifications 3 



American classifications 7 



Summary of previous classifica- 

 tions 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 



Einkorn 198 



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 grown 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 range 

 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- 

 tion:- and purposes, therefore, usually is given careful consideration 

 by grower-. The choice, however, is dependent upon the determina- 

 tion of identity. 



95589°— 22 — Bull. 1074 1 1 



