Hi, Carol, I'm back from vacation. Your question is worthwhile on Conch-L,
inasmuch as poison ivy is the most common hazard that a fossil shell
collector faces in the woods of eastern North America. If it's a vine with
consistently 5-leaved clusters of leaves, then it's probably Virginia
creeper and not allergenic. Poison ivy has "leaves three." The leaves are
glossy, and their margins are usually slightly (not thoroughly) jagged. The
vine form has myriad rootlets that resemble coarse hair. The plant has
clusters of whitish berries in the fall. It is deciduous.
 
Poison ivy has herb, vine, and bush forms, and is dismally common in
eastern North America, especially in disturbed ground in the woods or at
its edge. A related species (poisonwood) grows to tree size in the Bahamas.
The "poison" is an allergenic oil. For those who are susceptible, a mere
touch of any part of the plant leads to a painful, itchy rash that lasts a
few days. For those who are very allergic to poison ivy, even the smoke
from the burnt plant can be hazardous. In my experience, the ivy is most
potent when it has not rained for several days.
 
The best way to avoid problems with poison ivy while collecting fossils is
to recognize and avoid the plant. "Leaves three, let it be" is a good maxim
to learn. It also helps to cover your skin and not wear the same clothing
again before cleaning it if you think it may have contacted the plant. It
is not always possible to avoid touching poison ivy while climbing or
descending cliffs. If you touch poison ivy, then wash your hands off with
water as soon as possible afterward, and don't touch anything else until
you wash.
 
Treatment for the rash varies from person to person. I ignore it as best I
can, and this works for me. The best cure is prevention. If you are VERY
allergic to poison ivy, then it may be a good idea to collect fossils in
the winter!
 
Andrew K. Rindsberg
Geological Survey of Alabama