480 



WEED FLORA OF IOWA 



Figure 352A 



Pig. 352B 



Figure 3520 



Fig. 352D 



Fig. 352. Seeds (achenes) of: A. Gum Weed (Grindelia squarrosa), enlarged 

 and natural size. The one at the top shows the wrinkled appearance of the 

 corky-thickened angles. B, Canadian Goldenrod (Solidago canadensis). C, 

 Stiff Goldenrod (Solidago rigida). D, Late Goldenrod (Solidago serotina) . 



(A, after Hillman, Bull. Nev. Agr. Exp. Sta. ; C, drawing by Charlotte M. King ; 

 B and D, drawings by Ada Hayden). 



Stiff Goldenrod {Solidago rigida L.). 



Achenes ribbed, somewhat 4-angled, with minute ribs between 

 the angles; sear at base small, whitish, one-sixth to one-twelfth in. 

 long, pale straw-colored; pappus of minute capillary bristles of 

 nearly equal size, spreading. 



Late Goldenrod (Solidago serotina Ait.). 



Achenes minute, somewhat teretish, many-ribbed, minutely pu- 

 bescent, straw-colored, one-twentieth in. in length; small obovoid 

 scar at base, whitish; pappus spreading, of fine white capillary 

 bristles. 



