128 



WEEDS OF FARM LAND 



but on heavier land it is far more difficult to eradicate, as the 

 creeping stems are very full of vitality and each small broken 

 piece is capable of starting a new plant on its own account. 



Jn addition to these ubiquitous weeds which occur in such 

 quantities as to make them an important economic factor 

 there are a few others which are more or less uncommon but 

 which are equally cosmopolitan in habitat. Petty spurge and 

 field forget-me-not are widespread but never very plentiful. 

 The pale red poppy (P. dubium] occurs more frequently than 

 is recognised as it is probably often confused with the common 

 red poppy. 



Silverweed (Potetttilla anserine?) although it occurred in 

 IO per cent of the fields examined was frequently in such 

 small amounts as to be scarce. Only on three occasions was 

 it dominant and in each case this was on chalky land. It is 

 quite probable that this weed in spite of its general distribution 

 has some preference for calcareous soil. Creeping buttercup, 

 mouse-ear chickweed, field madder and wild radish are speci- 

 ally characterised by the number of times that they are scarce 

 when they do occur, as is shown by the following table : 



In addition to the weeds noted above, a number of others 

 occur with less frequency; in the course of the investigation 

 they were seen but twenty times or less in arable fields. The 

 indications are, however, that most of these plants are com- 

 paratively indifferent as to soil, as they were found on all 

 types of land. 



* Achillea millefolium 

 j&thusa cynapium . 



* Bellis perennis 

 Brassica campestris 

 Cirsium lanceolatum 

 Caucalis nodosa 



* Chrysanthemum leucanthemum 



* Lychnis dioica , . 



Yarrow. 

 Fool's parsley. 

 Daisy. 



Field cabbage. 

 Spear thistle. 

 Knotted caucalis. 

 Dog daisy. 

 Red campion. 



