78 COMMON WEEDS 



are a frequent impurity in samples of clover and rye- 

 grass seeds. 



Herb Robert (G. Robertianum L.) is a well-known 

 flower of hedgerows, roadsides, and waste places, but 

 occurs also in both grass and arable land, especially 

 on loamy, clayey, and calcareous soils. It is the most 

 common and generally distributed of the Crane's-bills. 

 The straggling branched stems are reddish, brittle, and 

 somewhat hairy ; the leaves are segmented and pinna- 

 tifid, and in autumn become reddish like the stems ; 

 the flowers, J inch across, are bright pink, elegantly 

 veined and streaked with dark and light red. The whole 

 plant has a strong, but not altogether unpleasant, smell. 



Wherever the Crane's-bills occur in cultivated crops 

 they should be eradicated, more especially when clovers 

 or grasses are intended for seed. They may be re- 

 moved by hand from clovers and rotation grasses, and 

 this should be done early before the seed is ripened. 

 All are propagated only by seed, and in hoed crops 

 therefore may easily be destroyed, as they are seldom 

 very plentiful in such positions. As regards grass land, 

 see p. 159. 



ROSACES 



Silver-weed or Goose Grass (Potentilla Anserina L.) 

 is a perennial weed of prostrate habit, very common by 

 roadsides, its glossy, silky, silvery-white pinnate leaves, 

 bright yellow flowers, and long runners making it a 

 conspicuous object in the summer months (Fig. 17). 

 It is occasionally a serious pest on arable land, growing 

 well on almost all soils, especially when these are 

 damp. Silver-weed is not easily eradicated, as the 

 runners are readily broken, and, as they root at the 

 nodes, small pieces form new plants. Where the weed 

 is a pest it should be given no rest during which it can 



