8 
BULLETIN 1045, U. S. DEPARTMENT OF AGRICULTURE. 
Wiley (19) says that three principal varieties are grown in Russia: 
One with large white seeds, valued for its high oil production; one 
with smaller black seeds, which are sweeter and regarded as best for 
eating; and the intermediate form with striped seeds, used both for 
food and for oil production. 
The common wild sunflower of the United States often has a much- 
branched stalk (fig. 2) , with numerous heads 3 to 4 inches in diameter. 
The yield of silage produced by this plant when grown on rich soil 
under cultivation is usually somewhat less than that obtained from 
the Mammoth Russian varietv. under the same conditions. At Red- 
Fig. 2. — Two rows on the left, Mammoth Russian sunflowers ; two rows on the right, wild 
sunflowers, Redfield, S. Dak. Both varieties were seeded on April 28, 1920, and photo- 
graphed in August. 
field, S. Dak., in 1920 the total crop, green weight, of the wild sun- 
flower was 13.9 tons per acre, while the Mammoth Russian in an 
adjoining plat yielded 15.2 tons per acre. 
There has been no extensive development of sunflower varieties 
in the United States. The seed trade has advertised at times six 
or eight supposedly different varieties, but many of these are only 
slightly differing strains or selections of the same variety. Probably 
the most extensive varietal trial made was that of the Department of 
Agriculture of Ontario, Canada. In 1894 and 1895 seven varieties 
were under test at Ottawa. 5 These varieties. Helianthus globosus, 
5 Ann. Rpt., Dept. of Agr., Ontario, v. I, p. 261. 1895. 
