2i6 Weeds. 



ers are borne on the ends of the branches ; 

 the calyx, which encloses the seed pod, 

 becomes much swollen as the seed develops. 

 The plant blooms in June and July, and 

 ripens its seed with the grain. 



The rather large, somewhat flattened 

 black seed occurs commonly in thrashed 

 wheat, where it is easily recognizable and 

 difficult to remove. This seed is particu- 

 larly objectionable in wheat, as when it is 

 ground with the grain, it gives the flour a 

 dark color and unpleasant taste, and is said 

 to be unhealthy. The seed is poisonous to 

 chickens, hence screenings which contain it 

 should not be fed to poultry. 



The white cockle (Lychnis alba) and the 

 sticky cockle or night-flowering catchfly 

 (Silene noctiUora), the former a white- 

 flowered biennial and the latter a sticky, 

 hairy annual with yellowish-white flowers, 

 are closely related plants which sometimes 

 occur in grain fields and meadows. A short 

 rotation, with the rather frequent intro- 

 duction of a thoroughly cultivated crop, 

 will keep both these weeds in check. The 

 methods of eradicating corn cockle are 

 equally effective in handling white cockle 

 and night-flowering catchfly. 



