NINTH ANNUAL YEAR BOOK— PART V 195 
I may say that quite a number of persons sent specimens of weeds in 
response to the queries. Many sent full replies and that most of them 
stated that the weeds occurred on highways, private grounds and railway 
right-of-ways, and that as a rule about one-half of the correspondents 
gave short methods of extermination in response to queries numbers four 
and five. 
Cocktehur. 
Of the list of weeds, Cocklebur has been reported from nearly every 
county in the state, but it is more abundant in southern than in northern 
Iowa. More replies were, however, received from Sioux, Montgomery, 
Guthrie, Fayette, Linn and Benton counties. The weed is abundant in 
the state, not only along highways but also in fields. 
Canada Thistle. 
The replies indicate that Canada Thistle is widely scattered in the 
state but not abundant in any one place. From the replies received it 
would appear that it is abundant in the following counties: Winnebago, 
Winneshiek, Cass, Story, Cerro Gordo, in no case, however, except in 
Hardin county, does the weed cover large areas. 
Wild Mustard. 
This weed is widely scattered in the state, being most abundant in 
northern Iowa, less frequent in northeastern and southern Iowa. Not 
only reported as occurring along roadsides but in fields. It appears to 
be a legacy from flax culture and is being perpetuated by the sowing of 
oats that contains mustard seed. Reported from Sioux, Lyon, Emmet, 
Winnebago, Cerro Gordo and Sac counties. 
Quack Grass. 
The greatest interest seems to have been manifested in Quack Grass 
which has been reported from every county in northern Iowa and in 
many other counties. It is most abundant in the three northern tiers of 
counties. It seems to have spread not only from elevators, seed grain 
but straw which is transported from farm to farm. Its spread in one 
case in Story county can be traced to a farmer who sold his straw to 
neighbors. In this case it can be traced along the highway for several 
miles in each direction. It is without doubt the most serious weed pest 
in Iowa to-day. The counties most frequently reported are Winnebago, 
Hancock, Cerro Gordo, Fayette, Winneshiek, O'Brien; only reported in- 
frequently from southern Iowa. 
Squirrel-tail Grass. 
This weed no doubt occurs in every county in the state, although a 
few counties do not report it; the greatest number of replies have been 
received from Cass, Story, Winneshiek, Winnebago, Fayette, Greene, Linn 
and Harrison counties. It is reported not only on highways but also in 
fields and along railways. 
Siveet Clover. 
Correspondents generally reported sweet clover, perhaps more abundant 
in the western and central parts of Iowa than in eastern and northern 
Iowa. It is most frequently reported in Woodbury, Pottawattamie, Hum- 
boldt, Fayette, Greene, Montgomery, Story and Webster counties. 
