436 WEED FLORA OP 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 Cookie (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." 

 Found 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. 



* 



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 Bhrb.); 



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. 



