436 WEED FLORA OF IOWA 



Corn Cockle (Agrostemma githago L.). 



Seeds large, angular, broadly wedge-shaped, one-eighth in. in 

 length ; tubercles prominent, lines of tubercles beginning at basal 

 end of seed; color brown to black; size of seed variable; according 



» 



Fig. 277. Corn Cockle (Agrostemma githago'), a, seed enlarged; b, seed in 



cross section ; c, natural size. 



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



to Dewey the larger ones hard to screen out. Most commonly found 

 in wheat; seed has poisonous properties. "Pest in grain fields." 

 Pound in wheat and in chicken feed. 



Bladder Campion (Silene latifolia (Mill.) Brit. & Rendle). 



Seed kidney-shaped, more nearly spherical than in Silene nocti- 

 flora, one-fifteenth in. in length ; shape of seed more nearly or- 

 bicular than in S. noctiflora. Found in some clovers. 



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,ffA%. 





fflgggSs? 



J Vo*%;- i "/."'- -,--*•• 



Fig. 278. Bladder Campion (Silene latifolia). A, common forms of seeds, 

 side view. B, edge view of a seed, showing the scar-cavity. C, the nat- 

 ural size of the seeds. 



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



Forked Catchfly (Silene dichotoma Ehrb.). 



General shape of seed roundish triangular, somewhat flattened, 

 about 1.5 mm. in breadth ; color dull reddish brown ; 5-7 rows of 

 tubercles on each side in curved rows following the rounding out- 

 line of the shape of the seed; scar on the straight side of seed. 



