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AGRONOMY 



and P. Rugelii are common dooryard weeds with broad and 

 rounded leaves and slender spikes of inconspicuous flowers. 

 The third species, the narrow-leaved plantain (P. lanccolatcf), 

 is easily distinguished by its rosette of long narrow leaves 



veined lengthwise of the 

 blade. All the plantains 

 are easily dug up. 



Common bindweed (Con- 

 volvulus sepiuni). The 

 large white or pink fun- 

 nel-shaped flowers, like 

 morning-glories, make the 

 bindweed conspicuous 

 and well known. It is 

 fond of rich soil and 

 forms tangled mats over 

 the vegetation in the 

 fields where it grows. It 

 has a creeping under- 

 ground rootstock that 

 makes it one of the hard- 

 est of weeds to eradicate. 

 Black bindweed (Poly- 

 gonum convolvulus). The 

 climbing stems of this 

 plant overrun other plants 



Photograph from American Steel and Wire Co. 



FIG. 121. A common wild lettuce related 

 to the prickly lettuce 



in its vicinity, after the 

 manner of the common 

 bindweed, to which, how- 

 ever, it is not closely related. It is a much slenderer plant 

 with greenish flowers and seeds that suggest its relative the 

 buckwheat. Being annual instead of perennial, it is a much 

 less formidable species than the common bindweed, though 

 its vigorous growth makes it a harmful weed. 



