KINDS OF WEEDS 



243 



412), kinghead (an ambrosia), mustard or charlock (Fig. 413) 

 are weeds of grain crops; dock, plantain, hound's-tongue, 

 burdock and catnip (Fig. 414) are weeds of back yards and 

 by-ways; sorrel, mullein, evening prim- 

 rose (Figs. 276, 415) are denizens of old 

 fields; ragweed (Fig. 416), mayweed 

 (417), stick-tight (Fig. 418), prickly 

 lettuce (Fig. 86), sweet clover (Fig. 

 184) and Russian thistle (Fig. 113) are 

 suited to roadsides and waste places. 



412. Chess or cheat. 



413. Charlock, a weed of 



grain fields and open 414. Catnip, often a weed 



places. about old places. 



413. Some weeds come and go year by year; these are 

 mostly weeds of tilled and raw ground, and usually annuals, 

 as pigweeds of several kinds, pepper-grass, purslane, rag- 

 weed, pigeon-grass, jimson weed (Fig. 275). Such weeds are 

 avoided by the use of clean seed, preventing the weeds from 

 ripening seeds, and taking care not to spread them in manure. 



414. Some weeds have a two-year cycle, making a tuft 

 or getting a foothold one year and ripening seed the follow- 

 ing year. These are biennials, as mullein, burdock, bull 

 thistle (Fig. 254), evening primrose, wild carrot, creeping 



