BULLETIISr 176^ U. S. DEPARTMENT OF AGEICULTURE. 



The 9 classes are as follows: 



(1) Yellow, round. 



(2) Yellow, oblong. 

 (•3) Yellow, long. 



(7) Rose or red, long. 



(8) Violet colored. 



(9) Streaked (mottled). 



(4) Flesh colored, oblong. 



(5) Rose or red, round. 



(6) Rose or red, oblong. 



The varieties included in class 1 are divided into ten sections, of 

 which section 2 is perhaps a representative example. 



Section 2. — Tubers yellow or white, round; flowers colored, often abundant; flesh 

 white; sprouts violet, more or less colored. 



One of the ablest attempts at group classification in this country is 

 that of Kohler/ who, in March, 1909, published the first results of his 

 studies on the classification of potato varieties. His grouping of the 

 varieties is based upon the following points: (1) Characteristics of 

 vines; (2) shape of tubers; (3) color of tubers. 



Eleven groups were described in 1909, viz: 



(1) Tuberosum group. 



(2) Rural group. 



(3) Endurance group. 



(4) Seedling B group. 



(5) Green Mountain group. 



(6) Carman group. 



(7) Early Michigan group. 



(8) Milwaukee group. 



(9) Russet group. 



(10) Ohio group. 



(11) Early Market group. 



In a subsequent publication, April, 1910, Kohler retained the same 

 number of groups, but submitted new names for four of them, his 1910 

 list being as follows: 



(1) Tuberosum group. 



(2) Wohltmann group. 



(3) Rural group. 



(4) Endurance group. 

 "(5) Factor group. 



(6) Sharp's Express group. 



(7) Green Mountain group. 



(8) Michigan group. 



(9) Russet group. 



(10) Ohio group. 



(11) Cobbler group. 



In many respects Kohler's grouping is satisfactory, but one might 

 question the advisability of giving to any one group the name ' ' Tuber- 

 osum." If all of the cultivated \'arieties are to be regarded as belong- 

 ing to Solanum tuberosum, a group of only a few varieties can not be 

 considered as exclusively entitled to such a designation. Exception 

 might also be taken to three of the 1910 groups — Wohltmann, Factor, 

 and Sharp's Express — which derive their group names from foreign 

 varieties. It would seem desirable that the type variety should be 

 one of American origin. 



In 1912 Milward ^ mentions three groups^as representing distinctive 

 types. These he called the round-white, the long-white, and the Rose 

 groups. 



1 Kohler, A. R. Potato experiments and studies at University farm. Minn. Agr. Exp. Sta. Bui. 114, 

 p. 311-319, 1909. 



Kohler, A. R. Potato experiments and studies at University farm in 1909. Minn. Agr. Exp. Sta. Bui. 

 lis, p. 90-100, iUus., 1910. 



2 Milward, J. G. Commercial varieties of potatoes for Wisconsin. Wis. Agr. Exp. Sta. Bui. 225, p. 7, 

 1912. 



