34S 



WEED FLORA OF IOWA 



Extermination. — This is a most troublesome weed in com and 

 smaller grain fields of northern Iowa. The somewhat thickened 

 underground stems spread the plant freely by cultivation. The 

 small-grain field should be plowed after the grain is removed, 

 then dragged so as to expose the "roots" to the sun. Before 

 planting corn in the spring run a disk over the field, then har- 

 row, plant to corn, and give thorough cultivation. When the weed 

 is very bad it may be well to get the field .into meadow or pas- 

 ture. 



Maximilian's Sunfiower {Heliantkus maximiliani Sehrad.). 



Description. — Stem scabrous and hispid, 2-12 ft. high, the latter 

 height being obtained in alluvial bottoms ; leaves usually alternate, 

 thick, becoming rigid, scabrous above, hairy beneath, lanceolate, 



Pig. 203. Maximilian's Sunflower. (.Helianthus maximUianil. Common In 

 meadows and fields of northern Iowa. Yellow flowers, hairy elongated 

 leaves. 



(Photographed by Colbum.) 



