8 The Colorado Experiment Station. 
1 lie money received for Colorado potatoes is largely net gain 
to the State as very little money is sent out for fertilizers, etc. 
The potato crop at present brings to the growers approximately 
$6,000,000 a year. Colorado has undeveloped lands enough to make 
the total output several times what it is at present. 
THE BOTANY OB THE POTATO. 
Solatium Tuberosum, is the botanical name for the common 
potato of commerce. It is closely related to the tobacco and tomato 
and to the nightshade, the egg-plant and the buffalo-bur. Other 
species of tuber-bearing Solanums have been domesticated in the 
hope of finding a potato equally as good as tuberosum, and one that 
would be more resistant to fungus diseases. Among these are 
Commasonii, Maglia, and Jamesii, the last being a native of the 
mountains of southwestern Colorado. None of these species have 
ever become valuable as a source of human food. 
What Is a Potato? —Botanically, the potato is a tuber or en¬ 
largement in a stem or branch, normally under ground, but some¬ 
times above, even in upper branches when disease or accident has 
interfered with the formation of tubers below ground. Not infre¬ 
quently growers speak of the potato as a root, or growth from the 
loot. The tuber has no connection with the root system of the 
plant. This structure of the potato may be best observed by ex¬ 
amining the the plant about the time the blossoms are forming. If 
the plant is carefully dug, the small stems will be observed growing 
from the main stem of the potato above the seed piece from which 
the plant came. 
Tuber Stems Vary greatly in length with the varieties. The 
stem of the Peail is short, and the tubers are set close in around 
the old seed piece. The stems and tubers of a Rural New Yorker 
go more deeply into the soil. The Peachblow has not only a long 
undeigiound stem, but often the stem continues through the first 
tuber, so as to have two or even three tubers on the same stem. 
Potatoes from Seed. —While the plant is usually reproduced by 
cuttings of the tuber, it may be reproduced from true seed, as it 
undoubtedly is propagated in part under wild conditions. Many 
of our best varieties of potatoes, however, never produce seed balls, 
nor even perfect blossoms. (For a discussion of this point see 
Bulletin No. 176.) 
The Function and Development of the Tuber. —The plant food, 
elaborated by the plant during the summer, is deposited in the tuber 
for the use of coming generations of plants, and a very large part 
of this food is deposited during the last weeks of the plants’ 
growth.* 
*For an explanation of tuber structure see Quality of Potatoes herein. 
