178 



WEED FLORA OF IOWA 



cal ; pinnate leaflets, 7-21 with smaller ones between, oblong, sharply- 

 serrate, silky ^tomentose beneath ; flowers with 5 bright yellow petals ; 

 peduncles elongated ; styles filiform. 



Distribution. — Common eastward in brackish marshes; also in 

 the Dakotas and the Rocky mountains ; common in "Wright county, 

 Iowa ; perhaps in other places. 



Extermination. — Give a shallow cultivation; expose the roots to 

 the sun. Care must be used to kill the weed on its first appearance 

 as it is quite persistent. 



Wild Rose (Rosa pratincola Greene). 



Description. — Low shrub with very prickly stem; compound 

 leaves of 7-11 leaflets, broadly elliptical to oblong-oblanceolate, sub- 

 cuneate at base, short stalked or sessile, serrate; stipule narrow, 



Fig. 101. Wild Rose {Rosa pratincola). Grain fields, roadsides. 

 (Photographed by Colburn.) 



