344 



WEED FLORA OF IOWA 



Meadow or Saw-toothed Sunflower {Helianthus grosseserratus 



Martens) . 



Description. — A tall, glabrous perennial 6-10 ft. high, bear- 

 ing numerous short peduncled heads; lower stem leaves 8-10 in. 

 long and petiole 1-2 in. long; leaves opposite or alternate with a 

 slender petiole, oblong, lanceolate, acuminate with sharp teeth, or 

 the upper merely denticulate, somewhat scabrous above, whitish 

 below; heads Y 2 in. high with deep yellow rays about an inch long; 

 bracts of the involucre slender. 



Distribution. — Common in the central states and northward, also 

 westward to Texas. Abundant throughout the state of Iowa in 

 corn fields, low swales and roadsides, particularly in northern 

 Iowa. 



Fig. 200. Meadow Sunflower (Helianthus grosseserratus) . Common in meadows, 



pastures and fields. 

 ( Photographed by Colburn. ) 



