88 



WEED FLORA OF IOWA 



Marsh Smartweed {Polygonum muhlenoergii (Meisn.) Wats.). 



Description. — A somewhat pubescent or scabrous perennial with 

 large black roots, decumbent or erect; leaves lanceolate to ovate, 

 narrowly acuminate ; flowers in rather long hispid spikes ; sepals 5, 



Fig. 50. Tanweed, Marsh or Muhlenberg's Smartweed, Devil's Shoe-string or 

 Shoe-string (.Polygonum muhlenbergii) ; o, plant hairs. Low meadows and 

 fields. 



(Photographed by Colburn. Drawing by Charlotte M. King.) 



Fig. 50- A. Distribution of Marsh Smartweed. 



