DIVISION IV 



FLOWERS INCOMPLETE ; COROLLA WANTING ; 

 SEXES OFTEN SEPARATE 



Dock Family {Polygonacece). — The genus Poly- 

 gonum has twelve British species. It has a calyx 

 of five sepals, a variable number of stamens, and a 

 pistil of two or three coherent carpels forming a 

 httle nut-like fruit. 



Many are readily eaten by animals, but others, 

 as the hot-tasting Water-pepper of our ditches {P. 

 Hydropiper\ are refused by them. The very astrin- 

 gent Bistort {P. Bistorta) is only eaten by certain 

 animals, as the horse, and P. ainpJiibiiim by cows. 



Black Bindweed {P. Convolvulus). — This is 

 the only species to which any special attention need 

 be drawn. It is very common in cornfields ; the 

 stem climbs up the stalk of the wheat, and apart 

 from its flowers, closely resembles the Lesser Bind- 

 weed {Convolvulus arvefisis). If the seeds of this 

 plant are too much mixed with oats, it has been 

 found that, after a considerable period, serious 



internal derangements follow. 



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