DESCRIPTIVE MANUAL 331 



We did try it on a neighbor's farm under the most disadvantag- 

 eous eireumstanees imaginable. The field was a pasture of blue 

 grass and wool grass with a very little white clover. The ground 

 was dry; as dry as we have ever seen it at that time of the year. 

 "We found it easy even under these hard conditions to drill in clover 

 on this tough sod and cover it from an inch to an inch and a half, 

 using a Hoosier drill with two horses. 



We found that the clover was dropped in the very bottom of 

 the slit made by the disk, a seed every two or three inches, using six 

 pounds to the acre. It lay there until the 23d of May, apparently 

 as dry as it came out of the drill, except in some of the lower spots, 

 where it had sprouted. The 23d of May there was a two-inch rain 

 on that field, and -at once the clovers began to grow." 



Perennial Ragweed {Ambrosia psilostachya D C). 



Description. — A branched hairy and rough perennial with slen- 

 der running root-stock, 2-3 ft. high; leaves once pinnatifid> acute 

 iobes, lower leaves incised; monoecious flowers, staminate flowers 

 with flattish involucres, involucre of fertile flowers, obovoid, tuber- 

 eles absent or very small. 



Distribution. — Common on gravel hills and sandy plains from 

 Illinois, Wisconsin to the Saskatchewan to the Rocky mountains, 

 common gravel knolls and sandy plains; Clinton, Muscatine, Car- 

 roll, Kossuth, Pottawattamie counties. 



Extermination. — Succumbs readily to cultivation. 



