AMERICAN VARIETIES OF SWEET POTATOES. 5 
soil selected has ranged from sand to a fine sandy loam. Most of the 
studies have been made from the crops grown at Washington, but the 
varieties have also been grown at Baton Rouge, La.. Florence, S. C, 
Norfolk, Va.. Columbus. Ohio, and Watson, N. Y., for the purpose 
of studying their behavior under different environments. The varie- 
tal descriptions were checked with the collections grown at all of 
the points mentioned; 
During the years the work has been in progress it has been the aim 
to test all varieties that are grown in the United States. New varie- 
ties have been added from time to time, and many so-called new varie- 
ties have been grown, only to find that they were old varieties given 
new names. It is believed that practically all varieties now grown 
in the United States are included in the present collection. All the 
important sweet-potato growing regions have been visited by those 
engaged in the work, and wherever a variety was found which was 
not definitely known it was added to the collection for study and 
comparison with the varieties being grown in the test. 
Before attempting to classify the varieties of sweet potatoes, care- 
ful descriptions were made of all varieties. Those showing a marked 
similarity were grouped together in the field for further compari- 
son. It has been found that all the varieties that have been grown 
can be placed in eight w 7 ell-clefined groups, each group being distinct 
and easily recognized. By means of a simple key, the group to 
which any variety belongs can be determined very easily and quickly. 
Each group has been given the name of the most widely known variety 
or the variety that is most typical of that group. Three of the large 
groups have been divided into sections to simplify the procedure of 
identification. It is believed that this grouping of varieties makes 
identification comparatively easy. After determining the group to 
which a variety belongs by means of the key the group description 
should be read to determine the section and the variety. To make 
sure of the correctness of identification, the descriptions of all varie- 
ties in the group should be read. 
As indicated in previous pages, no one character can be depended 
on to establish the identity of any sweet-potato variety; but rather 
a combination of characters, such as the length and character of the 
vines and the size, shape, and color of the roots. While typical 
specimens of such varieties as the Porto Rico, Big-Stem Jersey, 
Nancy Hall, Triumph, Yellow Strasburg, Southern Queen, and 
Pumpkin may be described as fusiform to globular, long fusiform, 
fusiform, medium to long cylindrical, globular, or ovoid in shape, 
an inspection of Plates I, II, and III, which show the variation in 
the size and the shape, of several specimens of each of these varieties, 
will show how great the variations in size and shape within the 
variety really are. 
