the country it has been very generally distributed throughout the 
United States. Throughout the southern New England States and 
in New York and Pennsylvania especially it has become extensively 
naturalized and is found growing wild very generally. In the States 
bordering on the Great Lakes, wherever waste land was found, its 
naturalization was proceeding rapidly until checked by the barberry- 
eradication campaign begun in 1918. In the Great Plains area it 
had not secured a strong foothold but nevertheless was planted ex- 
tensively. In the Southern States it was not planted to any great 
extent. The optimum development of individual plants appears to 
have been reached in the States of the Great Lakes region in lime- 
stone or sandy soil. Had its spread not been checked in most of this 
area, it is difficult to imagine to what extent it might have developed. 
The part that the barberry plays in the life history of the black 
stem rust of grains and grasses is too well known to need repeating 
here. That the barberry is the principal if not the only local source 
of stem rust in the spring in the northern part of the United States 
is well known. Its eradication, especially in the northern grain- 
growing areas, had often been suggested, but it was not until 1918 
that concerted action was possible. Acting on the suggestion of the 
United States Department of Agriculture, 13 of the North-Central 
States joined in a campaign to eradicate the common barberry and 
all other varieties known to harbor the rust. The campaign was 
organized under the direction of the United States Department of 
Agriculture, and a leader was placed in charge of the work in each 
State. Field men were employed to find and destroy the bushes. At 
first it was not thought necessary to keep very careful records of the 
exact locations of all bushes which were dug or otherwise removed, 
but the fallacy of this belief was evident when some of these loca- 
tions were inspected the second year and an appalling number of 
sprouts was found. More careful digging was required, and an exact 
record of all locations was kept. The check for sprouts also was 
made a regular part of the work, but still large numbers of sprouts 
occurred, and even two or three diggings failed to eliminate all of 
them. It soon became apparent that not only must the work be done 
more thoroughly but that more certain means of killing barberry 
bushes must be devised. This was especially true in areas of escaped 
bushes. 
In response to this demand the United States Department of Agri-. 
culture in 1921 started an intensive study of the common barberry 
with the object of ascertaining how the bush could be killed with a 
minimum of expense. The practical results of this study have been 
recorded in two circulars (15. 16) of the department. In the present 
bulletin is presented a discussion of results of digging barberries, 
together with details of all chemicals studied in the effort to find 
satisfactory chemical methods of eradication. 
THE COMMON BARBERRY PLANT 
The common barberry bush (pi. 1) usually is composed of a num- 
ber of stalks which arise from below the surface of the ground and 
grow to a height of 6 to 10 feet with few, if any, large branches 
except near the ground line. There may be 20 to 30 of these shoots 
