IMPROVEMENT OF GRASS LAND 207 



that Sorrel was much decreased by an application of 

 lime. Dressings of mineral manures weaken Sorrel, 

 and also encourage better herbage to choke out the 

 weed. Manurial treatment, however, should be prac- 

 tised in conjunction with regular cutting. 



URTICACE.E 



The Great (Stinging) Nettle (Urtica dioica L.) is 

 frequently a serious pest in certain parts of grass fields, 

 but usually only in 

 patches. It is a hairy 

 perennial, 2 to 4 feet or 

 more in height, with 

 large, heart-shaped ser- 

 rated and pointed leaves 

 placed opposite one 

 another in pairs on the 

 stem, and covered with 

 stinging hairs. The 

 flowers are borne in long 

 clusters or panicles (Fig. 

 61) in the axils of the 

 leaves. It quickly in- 

 vades adjacent soil by 

 means of its extensively 

 creeping underground 



FIG. 61. Stinging Nettle (Urtica dioica 

 Stems. It grows O11 most L.), x, with flower enlarged. 



kinds of soil and in al- 

 most any position, but thrives best on good land, such 

 as well manured gardens and paddocks. 



Nettles may be best destroyed by digging them out 

 by hand and burning them, but on large areas this is 

 impracticable, and regular mowing must be resorted 

 to, the successive cuttings taking place as soon as the 



