UNITED STATES DEPARTMENT OF AGRICULTURE 
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. Page. 
Necessity for a classification of wheat_ j | Classification of the genus Triticum_ 48 
Previous investigations_—___~_~--~- 2 Key to the species or subspecies_ 50 
Foreign classifications_________ 3 Common wheat_______ 5 50 
American classifications _-_---_ 7 Ghul awelie gs 2 ee en 172 
Summary of previous classifica- Zo wha d eawilie ats as aoe 180 
PONS *! 8 Bsa AT NE a $ Durumswheat 5) Ti Aue onee 183 
Present investigations ~____---_~-_ 10 A SDa a a gest koee siete pues AU Nen RCT US ee coer Vs A 193. - 
Classification nurseries_______— 11 ES aC Uo Rae Ds LAN a) ET 195 
Preparing descriptions, histories, Polish! wheait= 22) 2s Mabe ype 197 
and distributions _-_________ 15 ) EDs 01) og 3 eas SMP Rha OE Tae Ree a oF gE a 198 
Varietal nomenclature ___--_--~ 17 Unidentified varieties _________ 199 
The wheat plant 2L8 5.5 Lone Ba 22 | Estimated acreage of varieties _____ 207 
Morphological characters —_-__-~ JS papaitera tuney Chted ys seme ae eae eee 219 
Physiological characters___-_-- 47 |! 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- 
tions and purposes, therefore, usually is given careful consideration 
by growers. The choice, however, is dependent upon the determina- 
tion of identity. 
95539°-—22—Bull. 10741 1 
