150 FLORA HISTORIC A. 



We cannot close our history of the Convolvulus 

 without reminding our medical friends that it is 

 to this genus of plants that they are indebted for 

 two of their most powerful drugs. Jalap is ob- 

 tained from the Convolvolus Jalapa of South Ame- 

 rica, which takes its name from Xalapa, lying be- 

 tween Mexico and La Vera Cruz. 



The Scammony of the shops is obtained from 

 the Convolvolus Scammonia of the Levant, but our 

 great Bindweed is thought to possess the same 

 medical properties. Dr. Witherington remarks 

 that " it is unnecessary to import Scammony 

 from Aleppo, when a medicine with the very 

 same properties grows spontaneously in many of 

 our hedges." 



This genus of plants also affords the inhabit- 

 ants of tropical climates a valuable species of 

 food, as it is the Convolvolus Batatas which pro- 

 duces the tuberous roots called Battatas or Spa- 

 nish potatoes. 



