,B We ih PIN OR? TH E 
) USDRARTNT OF MRCUTIE 
No. 176 
Contribution from the Bureau of Plant Industry, Wm. A. Taylor, Chief. 
March 27, 1915. 
(PROFESSIONAL PAPER.) 
Gr 20UP CLASSIFICATION AND VARIETAL DESCRIPTIONS OF 
SOME AMERICAN POTATOES. 
By Wivi1aM Stuart. 
Horticulturist, Horticultural and Pomological Investigations. 
* _ INTRODUCTION. 
ETo those familiar tht thé present almost hopeless state of potato 
nomenclature it is apparent that there is a growing need for some 
imple and fairly reliable method by which the student and grower 
Gan recognize varieties well enough at least to place them in the fam- 
7 y “or group to which they belong. The classification of varieties into 
07 roups or families is admittedly the first step toward a satisfactory or 
ir ntelligent study of the varieties themselves. The increasing neces- 
sity for such study is clearly demonstrated by the large number of 
ld varieties offered to the public each year under the guise of new 
mes. This practice has naturally led to much confusion, and the 
a of restoring order out of the present chaos is a difficult one. 
s EARLY EFFORTS AT CLASSIFICATION. 
7 ame of the earliest and most careful attempts to classify varieties 
ito aor which has yet come to the writer’s notice is that of Vil- 
norin,! who in 1882 and again in 1886 and 1902 published the results 
eeey years’ phwearations of a very complete collection of potato 
eties. These varieties were grouped into 12 classes in 1886, and 
ihe 12 classes were further subdivided into 30 sections. In the 1902 
dition only 9 classes were made, but these 9 classes were subdivided 
ito 40 sections. The classification of the main groups is based on 
he e color and shape of the tubers; that of the sections is based on the 
olor, shape, and size of the coher and the depth of the eyes, the 
i olor of the sprouts in the dark, and the color of the flowers. 
sa 1 Vilmorin, C.P.H.L.de. Catalogue Méthodique et Synonymique des Principales Variétés des Pommes 
op erre. Paris, 1882. Ed. 2, corr. et aug. de plus de 200 variétés, 51 p., Paris, 1886. Ed. 3, refond. et 
* plus de six cents variétés, 67 p., Paris, 1902. 
Nore.—This bulletin is of value to plant breeders and potato specialists in all sections of the country. 
___-_73463°—Bull. 176-151 
