WEED MIGRATION 757 



before 1889. Since 1887 it has been well established in Ames; it 

 was reported from Ladora, 1895 (John Hiltbrummer) ; Des Moines, 

 1896 (C. N. Page) ; Westgate, 1902 (P. H. Hinager) ; Fort Dodge, 

 1912 (F. W. Paige) ; and very likely occurs in other places. It 

 was first introduced as a cultivated plant. This may become one 

 of the most pestiferous of our perennial weeds. 



EUPHORBIACEAE, SPURGE FAMILY. 



Snow-on-the-Mountain {Euphorbia marginata Pursh.). 



Indigenous to western Iowa. Little Rock, Sioux City, Onawa, 

 Council Bluffs and Hawarden. Naturalized east. Iowa City, 1887 

 (A. S. Hitchcock) ; Hamburg, 1888 (A. S. Hitchcock). Abundant 

 at Denison, 1894 ; Woodbine, 1894 ; Vale, abundant, 1894 ; Missouri 

 Valley, Carroll, 1895, abundant (W. Newell). 



GRAMINEAE, GRASS FAMILY. 

 Squirrel-tail Grass or Wild Barley (Horcleum jubatum L.). 



This plant was made known to science by Linnaeus, from speci- 

 mens found in Canada. Dr. Asa Gray, in his Manual of Botany 

 of Northern United States* in 1856, gives its distribution as 

 "marshes and moist sands of the sea shore and the northern lakes." 

 In 1868, its distribution was not extended, but Watson and Coulter, 

 who revised the manual (1890), add to the above "and westward." 

 In the seventh edition of Gray's manual the distribution is given 

 as "coast Labrador to New Jersey prairie and waste ground, 

 Ontario to Illinois, Kansas, and westward." It evidently is very 

 generally distributed throughout the United States. At Ames, 

 specimens have been received from Wyoming, Colorado, Nevada, 

 New Mexico, Idaho, Utah, Montana, Yellowstone Park, Illinois, Ne- 

 braska, the Dakotas, Minnesota, Kansas and from Argentine. It 

 has also been reported from California, Wisconsin, Arkansas, Mis- 

 souri, Michigan, Indiana, Ohio, New York, New Jersey, Massa- 

 chusetts, Maine, Canada (in many parts), Europe (Russia), and 

 Siberia in Asia. A truly cosmopolitan weed. 



We are without exact data in regard to its early appearance in 

 Iowa, though it was probably native in portions of western and 

 northwestern Iowa, especially where the soil was somewhat broken 

 up. From answers received it would seem that this grass has been 

 known in parts of Iowa for over fifty years, but it is only during the 

 last twenty-five years that it has made much headway. Though 



