WEEDS 



169 



be taken not to have it too strong if used in ponds in which 

 there are desirable species. 



Not all weeds are equally noxious ; moreover, what may be 

 a bad weed in one locality may be comparatively harmless in 

 another, perhaps because the crops are different, but there are 

 some species whose reputation for noxious qualities is world- 

 wide. Some of these are listed here. Other and more local 

 species may be studied in books devoted to the subject. 





Photograph from American Steel and Wire Co. 



FIG. 118. Dandelions gone to seed on a neglected lawn 



Purslane (Portulaca oleracea). This is a fleshy little mat 

 plant with small yellowish flowers that open only in sunshine, 

 and is related to the portulaca, or rose moss, of our flower 

 gardens. It will grow in almost any soil, and stores so much 

 water in its thick leaves that, after it has begun to bloom, it 

 can ripen its seeds though severed from the soil. 



Spreading amaranth (Amaranthus Uitoides). This species 

 resembles the purslane, but it is larger, less fleshy, and has 

 clusters of insignificant greenish flowers. Single specimens 

 may form mats more than a yard across. 



