370 



ELEMENTARY STUDIES IN BOTANY 



home of the potato, the wild plants occurring in the moun- 

 tains and highlands from southern Colorado, through Mexico, 

 and south into Chili. 



Although potatoes originated in America, they are not so 

 extensively used in the United States as in Europe. For 

 example, in the ten years extending from 1880 to 1890, the 

 average annual crop of the United States was 170 million 



bushels, while that of 

 Europe was over two 

 billion bushels. In 1912, 

 however, the crop of the 

 United States had be- 

 come 421 million bushels. 

 In 1911 the greatest 

 potato-producing states 

 were Wisconsin (32 mil- 

 lion bushels), Michigan 

 (31 million bushels), New 

 York (28 million bushels), 

 Minnesota (26 million 

 bushels), and Maine (21 

 million bushels). 

 The potato belongs to the nightshade family (Solanacese), 

 and in its genus (Solanum) occur not only the poisonous 

 nightshades, but also the edible egg-plant ; while some of its 

 associates in the family are tomato, red pepper, belladona, 

 petunia, and tobacco. The flower of the potato plant (Fig. 

 46) can be recognized by the blue or white corolla, which has 

 five broadly spreading lobes (" wheel-shaped ") ; and its five 

 stamens grouped together about the style, with anthers open- 

 ing by a hole at the top. The fruit produced by the flower is 

 a round green berry. The leaves are pinnately compound, 

 with minute leaflets intermixed with the large ones. 



The best soil for potatoes is a rich, sandy, well-drained 

 loam, forming a light soil, and this is indicated by the fact 



FIG. 45. The potato plant, showing the lower 

 part of the stem, the tubers, and the roots. 

 After SARGENT. 



