BULLETIN OF THE 



No. 176 



Contribution from the Bureau of Plant Industry, Wm. A. Taylor, Ch 

 March 27, 1915. 



(PROFESSIONAL PAPER.) 



GROUP CLASSIFICATION AND VARIETAL DESCRIPTIONS OF 

 SOME AMERICAN POTATOES. 



By William Stuart. 

 Horticulturist, Horticultural and Pomological Investigations. 



INTRODUCTION. 



To those familiar with the present almost hopeless state of potato 

 nomenclature it is apparent that there is a growing need for some 

 simple and fairly reliable method by which the student and grower 

 can recognize varieties well enough at least to place them in the fam- 

 ily or group to which they belong. The classification of varieties into 

 groups or families is admittedly the first step toward a satisfactory or 

 intelligent study of the varieties themselves. The increasing neces- 

 sity for such study is clearly demonstrated by the large number of 

 old varieties offered to the public each year under the guise of new 

 names. This practice has naturally led to much confusion, and the 

 task of restoring order out of the present chaos is a difficult one. 



EARLY EFFORTS AT CLASSIFICATION. 



One of the earliest and most careful attempts to classify varieties 

 into groups which has yet come to the writer's notice is that of Vil- 

 morin/ who in 1882 and again in 1886 and 1902 published the results 

 of many years' observations of a very complete collection of potato 

 varieties. These varieties were grouped into 12 classes in 1886, and 

 the 12 classes were further subdivided into 30 sections. In the 1902 

 edition only 9 classes were made, but these 9 classes were subdivided 

 into 40 sections. The classification of the main groups is based on 

 the color and shape of the tubers; that of the sections is based on the 

 color, shape, and size of the tubers and the depth of the eyes, the 

 color of the sprouts in the dark, and the color of the flowers. 



' Vflmorin, C. P. H. L. de. Catalogue Mc^thodique et Synonymique des Principales Vari6t6s des Pommes 

 de Tcrrc. Paris, 1882. Ed. 2, corr. et aug. de plus do 2n0 vari(5t6s, 51 p., Paris, 1886. Ed. 3, refond. et 

 aug. de plus de six cents vari6t6s, .'i7 p., Paris, 1902. 



Note.— This tiiilletin is of value to plant breeders and potato specialists in all sections of the country. 

 73403°— Bull. 17fr-15 1 



