- Toxicodendron radicans L. - Rhus toxicodendron - Poison Oak -
Rhus radicans L. - Rhus diversilobs L. - Cashew family Poison
Ivy is a climbing vine, Rhus toxicodendron, which on contact
produces a severe form of dermatitis. Rhus species contain
urushiol, and extremely irritating oily resin. Urushiol may also
be a potent sensitizer since in many cases subsequent contacts
produce increasingly severe reactions. Poison Oak is a climbing
vine, Rhus radicans or R diversiloba, closely related to poison
ivy and containing he same active principle. The symptoms and
treatment are identical with those for poison ivy. The oily
resin (sap) in the leaves, flowers, fruit, stem bark and roots
of poison ivy or poison oak causes a dermatitis resulting from
irritation or sensitization of the skin. There is no absolute
immunity although susceptibility varies greatly even in the same
individual. The plant is poisonous even after long drying, but
is particularly irritating in spring and early summer when it is
full of sap. The po