IOWA ACADEMY OF SCIENCES. 
115 
exclusion of all other plants. It showed evidences of long 
having been established. Since 1889 I have received specimens 
from Illinois and Iowa. The U. S. localities and dates, w^hen 
reported, are as follows: Upper Missouri, Hayden, “very 
abundant about old trading posts, along old roads, and in prairie 
dog villages on the Upper Missouri.” (Transactions Am. Phil. 
Soc., 1861.) 
‘ ‘ I see no difficulty in supposing that it is native to the region 
of the plains. It likes barren places; abounds where the grass 
is scant. In that may be found a reason why it appeared more 
in Iowa of late years.” J. E. Todd. We may assume that it 
has always been a native to the prairie states, especially west 
of the Missouri river. Early collectors — Geyer, 1839, who 
found it at Pierre, now South Dakota. Bexar: Texas, 1828. 
Rock Creek: Pendler, 1847. El Paso: Wright, 1849. North of 
the City of Mexico : Hartweg, 1837. Washita, Indian Territory, 
1868, Dr. E. Palmer. Abundant about Boulder and Denver 
from 1873 to 1876, Prof. Henry. Abundant at Denison, Texas, 
for twenty years, Munson. At least twenty to twenty-five 
years ^at Ennis, in north central Texas, Hogan. Tints far it has 
made but little progress in the timbered region of southeastern 
Texas. It has not been reported from Louisiana, and there are 
few indications of its occurrence in the Gulf states. Cultiva- 
tion, and the transit of cars from western states has caused the 
species to become abundant in the states that border on the 
Missouri river — Kansas, Nebraska, Western Missouri (where it 
was abundant in 1886, Tracy), eastern Kansas, eastern Nebraska 
and western Iowa. That it was not abundant throughout the 
plains may be assumed from the fact that in eastern North 
Dakota the plant is an occasional oddity, Bolley. It seems to 
have increased in number from the southwest to the northwest. 
Of its occasional appearance in the United States, outside of the 
territory indicated, it is reported more frequently from Illinois 
than elsewhere. Its migration there comes from Missouri and 
Nebraska, undoubtedly conveyed by stock trains. It seems to 
have been in parts of Tennessee, according to Gattinger, for 
thirty years, but has never become a serious pest. Prom pres- 
ent indications it may be many years till it will become a weed 
pest in states east of the Mississippi. 
Upper Missouri.— 1839. (Nicollet’s Northwest Expedition. 
Charles A. Geyer.) 
Upper Arkansas. — 1869. (Bristol.) 
