ANACARDIACEAE (CASHEW FAMILY) 



275 



A very poisonous plant, far too common everywhere, for to many 

 persons the touch of it brings disaster, blotching the skin with burn- 

 ing " water-blisters " and causing the flesh beneath to swell hideously 

 and throb with a pain so intense as to be alarming. Fortunately 

 such an attack leaves no scars and the general health is not injured. 

 Chemical analysis has shown that the poison is a nonvolatile oil, 

 found in all parts of the plant, even the seasoned wood, but espe- 

 cially in the growing leaves. It is insoluble in water, therefore wash- 

 ing the skin after contact merely serves 

 to spread the trouble; but alcohol will 

 at once dissolve and remove it, and, 

 if applied soon enough, will prove the 

 prevention that is better than cure. 

 If too late for that, a little powdered 

 sugar of lead, dissolved in alcohol, 

 will check the eruption and soothe the 

 pain. This remedy is also a poison, 

 and care must be taken to keep it 

 out of eyes and mouth, and of course 

 it should not be used if the vesicles 

 have broken; in such case dilute ex- 

 tract of Grindelia will check their 

 spread and soothe the smart. 



The plant is sometimes an erect and 

 bushy shrub, sometimes prostrate and 

 trailing, sometimes a long, woody vine, 

 climbing tall trees by means of aerial 

 rootlets. Leaves compound, with three 



leaflets, ovate to rhombic, pointed, usually entire but sometimes 

 scalloped or irregularly few-toothed, the two lateral ones sessile or 

 on very short stalks, the terminal one longer. In form they are 

 somewhat like the leaflets of the Virginia Creeper, or Woodbine 

 (Ps'cdera quinquefblia) , but it should be remembered that those are 

 five in number like the fingers of the hand, and can be safely handled; 

 but "Leaflets three, let it be." Flowers in loose, axillary panicles, 

 small, greenish white, with five-parted calyx, five petals, five sta- 

 mens and one-celled ovary. Fruit also greenish white, smooth, 

 and waxy, dangling in clusters of about the size of small currants, 



FIG. 192. Poison Ivy (Rhus 

 Toxicodendrori). X 



