According to some botanical studies Poison Ivy and Poison Oak are actually the same plant growing under different environmental conditions. One growing aspect is the tendency to climb, whereas forming a low shrub-like plant is another.
Rhus toxicodendron and Rhus radicans are names applied to the scientific identification. Both forms are equally toxic to most humans in causing itching or severe dermatitis.
Some hikers are occasionally fooled by the climbing Poison Ivy that reaches out from a tree trunk, resembling outstretched branches of the tree.
Copyright © 2006 William T. Hathaway.