448 WEED FLORA OF IOWA 



of eaulicle marked by groove ; color light brown ; seed coats do not 

 develop mucilage in water. Occasionally with clover. 



CAPPARIDACEAE, CAPER FAMILY. 



Eocky Mountain Bee-plant (Cleome serrulata Pursh.). 



Roughly wedge-shaped to triangular in outline, and wedge- 

 shaped in cross section; mature seeds of a grayish brown color, 

 immature seeds a creamy yellow ; size 3 by 2.5 mm. ; basal scar ex- 



Fig. 300. Rocky Mountain Bee-plant (Cleome serrulata). 

 (Drawing by Ada Hayden.) 



tends from the edge of the wedge, well up on both flat faces; 

 most of the surface of the seed roughly tubercled. 



ROSACEAE, ROSE FAMILY. 



Silver Weed (Potentilla anserina L.). 



Seed pointed, egg-shaped, unsymmetrical, about 1.6 mm. in 

 length ; color yellowish to brown ; surface furrowed throughout its 

 length. 



Fig. 301. Silver Weed (Potentilla anserina). 

 (After Burchard.) 



Cinquefoil (Potentilla canadensis L.) . 



Seed small, about 0.5 mm. in length, short, obliquely egg-shaped ; 

 lisrlit brown. 



