4S0 



WEED FLORA' OF IOWA 



Figure 352A 



We. 852* 



Figure 352C 



ng. 352D 



Fig. 352. Seeds (achenes) of: A. Gum Weed (GrindeKa aguarrosa), enlarged 

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

 corky-thickened angles. B, Canadian Goldenrod (.SoUdago canadensia) . C, 

 Stiff Goldenrod (.Solidago rigida). D, late Goldenrod (.SoUdago aerotina). 



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

 B and D, drawings by Ada Hayden). 



Stiff Goldenrod {SoUdago rigida L.). 



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

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

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

 nearly equal size, spreading. 



Late Goldenrod {SoUdago 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. 



