438 WEED FLORA OF IOWA 



Cowherb (Saponaria vaccaria L.). 



Seed nearly spherical, one-twelfth in. in length, minutely tu- 

 berclecl ; color black ; immature seeds reddish ; scar whitish, in de- 

 pression. Occurs in wheat and in red clover. 



• 



Fig. 281. Cowherb (.Saponaria vaccaria). A, different views of the seeds; 

 the one at the left and the lower one show the scar ; the light spots show 

 the minute surface-projections. B and C, parts of a broken seed, B re- 

 taining a part of the embryo. D, a sectional view of a seed. E, seeds, nat- 

 ural size. 



(After Hillman, Bull. Nev. Agr. Exp. Sta.) 



PORTULACACEAE, PURSLANE FAMILY. 



Purslane {Portulaca oleracea L.). 



Seeds broadly ovate, inclined to kidney-shaped, flattened, one- 

 thirtieth in. in length, roughened by minute tubercles in concentric 

 rows; small scar at smaller end, whitish. 



Fig. 282. Purslane (Portulaca oleracea). A, a side view of a seed, enlarged, 

 showing the whitish scar ; B, a group, natural size ; C, section of a seed, 

 taken parallel with the faces. 



(After Hillman, Bull. Nev. Agr. Exp. Sta.) 



RANUNCULACEAE, CROWFOOT FAMILY. 



Meadow Rue (Thalictrurn dasycarpum Fisch. and Lall.). 



Fruit an achene, ovoid, one-fifth in. in length, with remnant of 

 curved style, prominently ribbed, with from 6-8 wings, short- 

 stalked, glabrous or pubescent ; seed elongated, ovoid, one-tenth in. 

 long, brownish, smooth, with prominent veins near base of seed. 

 Occasionally found in clover seed. 



