35 



The large flowering spurge (E. eorollata) and the ipecac spurge (E. 

 ipecacuanhae) produce the same effect as the above species, but not so 

 frequently and only to a minor degree. The effect of all is to be coun- 

 teracted in the same way as the effect of the caper spurge. Children 

 should be especially warned against handling them. 



SUMAC FAMILY (ANACARDIACEAE). 



POISON IVY, POISON OAK, AND POISON SUMAC. 



Bhus. 



Woody perennials, with alternate, mostly compound leaves and 

 small greenish-white or yellowish flowers. All the well-known species 

 with an upright terminal cluster 

 of colored fruit are harmless. 



POISON ivy. 

 Bhus radicans L. 



Other names : Poison oak ; poi- 

 son vine ; three-leafed ivy ; poison 

 creeper; mercury or markry (N. 

 H. and N. J.); black mercury 

 (Me.) 5 markweed (Me.); pickry 

 (Me.). (Fig. 17.) 



Description and habitat. — A 

 climbing or trailing shrub (some- 

 times erect), with variable three- 

 foliate leaves, aerial rootlets, 

 and greenish flowers, appearing 

 in May and June. The smooth, 

 wax}- fruit often remains on the 

 plant until late in winter. The 

 leaves often resemble those of 

 the box elder, as in the figure; 

 but their margin is not seldom 

 almost entire. They differ from . 

 those of the Virginia creeper 

 in having only three leaflets 

 instead of five. Poison ivy 

 grows everywhere in open brush, 

 in ravines, and on the borders 

 of woods, and it is spread along 

 roadsides and cultivated fields from seeds carried by crows, wood- 

 peckers, and other birds that feed upon its fruit in winter. The plant 

 occurs abundantly throughout the United States as far west as eastern 

 Texas, eastern Kansas, and Minnesota, and in greater or less abundance 

 throughout the less arid region of the West, with the exception of Cali- 

 fornia, where it appears to be entirely replaced by Bhus diversiloba. 



'iu. 17.— Poison ivy (Rhus radicans) : a, spray show- 

 ing aerial rootlets anil leaves; b, fruit— both one- 

 fourth natural size. 



