[Illustration: Poison-ivy, poison-oak
_Rhus Toxicodendron--ANACARDIACEAE_]
=Description=: Probably no other plant has caused as much suffering and
distress as has the poison-ivy. Poison-ivy, with its characteristic
three-leaf appearance and prominent veins is a woody vine, climbing by
aerial rootlets, or taking a tree-like appearance. Poison-oak is more
of a low, branching shrub. Each leaflet is shaped somewhat like an oak
leaf. Both are found abundantly in woodlands, along fences, walks,
and roadsides. During the fall their showy red and yellow leaves are
frequently mistaken for those of the harmless trees of the woods.
The flowers are yellowish green to white in color and formed in
clusters attached to the stems, or in the stem forks. Fruits are smooth
globular structures, sometimes remaining on the branches until spring.
=Poisonous Parts=: All parts of the plant are poisonous, even the tiny
plant hairs and the smoke from burning the leaves in the fall. This
plant produces a severe dermatitis upon contact causing inflammation,
blistering, and vesicles. As the skin breaks, a liquid exudes and scabs
or crusts form.
The poisonous principle is a reddish-brown, oil-resin containing
=urushiol=. This can produce irritant effects within 24 hours upon
contact with the skin.
=Antidotes=: Numerous remedies are available in pharmacies for
poison-ivy. After contact, or suspected contact, hands, face, and
affected parts should be first washed freely with soapy water using
laundry soap of the alkali kind; lather abundantly. Soaps containing
oil or greasy components should not be used. The poison is soluble in
them and will spread over the skin. In severe or persistent cases of
dermatitis, consult your physician.
Physicians treat itching, severe inflammation, and pain when dermatitis
becomes evident.