UNITED STATES DEPARTMENT OF AGRICULTURE 



BULLETIN No. 1021 



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Contribution from the Bureau of Plant Industry 

 WM. A. TAYLOR. Chief. 





Washington, D. C. 



PROFESSIONAL PAPER 



April 17, 1922 



GROUP CLASSIFICATION AND VARIETAL DE- 

 SCRIPTIONS OF AMERICAN VARIETIES OF 

 SWEET POTATOES. 1 



By H. C. Thompson, formerly Horticulturist, and James H. Beattie, Horticul- 

 turist, Office of Horticultural and Pomological Investigations. 



CONTENTS. 



Importance of varietal classification 



of sweet potatoes 



Early attempts at classification 



Proposed system of classification 



Key to the groups 



Descriptions of the groups 



Ticotea group> 



Belmont group 



Spanish group 



Shanghai group 



Florida group _. 



Page. 



Page. 

 Description of the groups — Contd. 



Southern Queen group 9 



Pumpkin group 9 



Jersey group 10 



List of varieties included in the key_ 11 



Descriptions of varieties 11 



Check list of names used in sweet- 

 potato literature is 



Bibliography of sweet-potato litera- 

 ture 26 



IMPORTANCE OF VARIETAL CLASSIFICATION OF SWEET 



POTATOES. 



To those familiar with the present state of sweet-potato nomen- 

 clature it is apparent that there is need for some simple system of 

 classification by which varieties may be identified well enough to 

 place them in the groups to which they belong. The need for such 

 a classification is clearly shown by the large number of new names 

 that each year are given to old varieties. The need is also readily 



1 Credit for the description of many of the varieties of sweet potatoes and for the 

 working out of the system of classification contained in this bulletin is due F. J. Tyler, 

 formerly assistant in botany of the Bureau of Plant industry. 



The main portion of the work was done by Mr. Tyler between 1902 and 1906 ; the addi- 

 tion of a number of important varieties not studied by Mr. Tyler and further work on all 

 the varieties has necessitated changes in the key and in some of the descriptions. 



During the progress of these investigations considerable work has been done by W. R. 

 Beattie, horticulturist ; Chester J. Hunn, assistant horticulturist ; and H. M. Conolly, 

 formerly assistant horticulturist, Office of Horticultural and Pomological Investigations, 

 Bureau of Plant Industry. 

 71638° — 22 1 



