io 4 



FLOWERS OF THE CORNFIELDS 



honey glands are situated, and two in the place of the functionless 

 stamens that do not produce pollen. 



The glands can be seen when the calyx expands, and are visible 

 and accessible from outside. Insects can reach them without touching 

 any of the other parts of the flower. The insect thrusts its proboscis 

 down between the stamens, because the flowers are so close. The 



stamens later lengthen 



. +* H1HHB anc ^ are nv ' st(J( l out ~ 



wards, and the oppor- 

 tunities for cross-pol- 

 lination agree with 

 the conditions in 

 Cardamine pratensis. 

 When the flowers 

 wither and the stigma 

 lengthens the anthers 

 turn the pollen- 

 covered sides up- 

 wards, bend down- 

 wards, and self-pol- 

 linate the plant. The 

 visitors are Diptera 

 (Syrphidae), Hymen- 

 optera (Tenthredin- 

 idse, Apidse), Coleop- 

 tera (Coccinellidae), 

 and Lepidoptera 



(Euclidia glyphica, 

 Burnet Noctua). 



The seeds of 

 Charlock are dis- 

 persed by the plant 



itself. The pods open and allow the seeds to be scattered around 



the parent plant. 



It is a sand plant, and requires a sand soil, which may be derived 



from any of the older formations, such as Coal-measures, Keuper, Lias, 



&c., in which there are sandstones. 



This plant is infested by Ceuthorhynchus sulcicollis, Psylliodes 



chrysocephahis, Meligethes (zne^ls, Balanienus brassier (Beetles), Athalia 



spinarum (Hymenoptera), Large White (Pieris brassier), Small White 



(P. rapee\ Green-veined White (P. napi), Turnip Moth (Agrotis 



CHARLOCK (Brassica arvensis, O. Kuntze) 



