ANACARDIACE^— SUMAC FAMILY 



THE POISON IVIES 



Rhus microcdrpa. Rhus toxicodendron. Rhus radicans 



Two plants now known as Rhus microcdrpa and 

 Rhus radicans were formerly considered as a single 

 species and very generally described under the name 

 Rhus toxicodendron, which name is now given to a 

 third species of southern habitat. As a result the 

 amateur and the layman find themselves considerably 

 confused when they consult the talent. 



But the main facts in the matter still stand clear. 

 Both are plants poisonous to the touch, and to many 

 persons the neighborhood of the plants is dangerous. 

 Both have compound leaves of three leafletSj not five 

 like the Virginia Creeper, nor seven to nine like the 

 Bittersweet. There are always three leaflets, there are 

 never any more. The specific differences are largely 

 those of habit of growth, the blossoms and the fruit 

 are virtually the same in both. 



Rhus microcarpa, the common roadside Poison Ivy, 

 is the running vine so abundant in fields and by the 

 roadsides. The hairy stem often trails upon or just 

 under the ground and sends up erect branchlets six to 

 eight inches high which make a low thicket; some- 

 times the entire plant is erect but low. 



Rhus radicans is a woody, hairy vine climbing by 



numerous dark-colored aerial rootlets, the stems 



sometimes an inch or more in diameter. It climbs 



fence posts especially, and often trees, now and then 



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