IOWA ACADEMY OF SCIENCE 
39 
Utah and Idaho and according to Robinson and Fernald is locally abun- 
dant in New Brunswick, New England, New York and Pennsylvania 
and about St. Louis. Here we have a most aggressive Pacific slope weed 
which has adapted itself to a wide scope of territory. It is one of the 
few Pacific slope weeds which has thus extended its territory eastward. 
The Goldenrods are poorly represented in Northwestern Canada. The 
Missouri Goldenrod {SoUclago missouriensis) is common in Southern 
Manitoba to Winnipeg Beach and westward, but scarcely weedy. The 
rigicla occurs in Manitoba but not a common plant. A very common 
weed in Iowa pastures. The Canadian Goldenrod {S. canadensis) is 
common in Illinois, Wisconsin, Missouri, Nebraska and Minnesota, often 
weedy in pastures and along roadsides but seldom so in Manitoba. It 
occurs, too, on the west slope of the Cascades near North Bend and else- 
where. The Sow Thistle {S. oleraceus) occurs in Winnipeg, more fre- 
quent on the Pacific Coast, Seattle and elsewhere, on the other hand, 
the perennial Sow Tliistle {S. arvensis) is abundant everywhere in Mani- 
toba from Emerson to Winnipeg and westward through the older settled 
portion of Manitoba! Some fields and pastures are yellow with its 
flowers. It is spreading about St. Vincent, Minnesota, and Pembina, and 
other parts of North Dakota. It is rare in other Northern Mississippi 
Valley states. It is one of the greatests pests of the Canadian wheat field. 
A field covered with it is not productive unless the summer fallow method 
is pursued, and this is an expensive operation and not economic where 
the one crop method is followed. 
The Dandelion {Taraxacum officinale) is common everywhere from 
Winnipeg to the coast, south to Seattle. , The Cocklebur {XantJiium can- 
adense) from Minnesota to Texas and even in cultivated fields of the 
Colorado Rockies, so common to the south can scarcely be regarded as 
a very troublesome weed in Canada, although found about Winnipeg 
and AVinnipeg Beach, and west to Moose Jaw. A most troublesome weed 
in the corn belt region. 
The Cat’s-ear {Hypocliaeris radicata) which is -naturalized from Eur- 
ope and a ballast weed along the Northern Atlantic Coast, does not 
occur in the Northern Mississippi Valley; it is one of the most common 
weeds in lawns and in waste places from Oregon to Vancouver and the 
Vancouver Island. There is a common impression in Oregon that this 
Aveed Avas introduced in that state from Chili. A related species H. 
glahra is naturalized in California and occurs sparingly in Maine. The 
HaAAdvbit {Leontodon autumnalis) is common in the eastern states and 
in Ontario but has not found its way to the Northern Mississippi Valley. 
The GoaUs Beard {Tragopogon pratensis) is a common plant in the 
