Ask Mr. Smarty Plants

Poison ivy is a plant that has a very broad native range in North America and can have a varied appearance in different locations. Toxicodendron pubescens (Atlantic poison oak) looks different than Toxicodendron radicans (Eastern poison ivy) which looks different than Toxicodendron rydbergii (Western poison ivy) and none of the photos look like the poison ivy that I was familiar with in NJ/PA or see in Ontario.  Not to mention that it grows in sun or shade and looks different under those conditions.

I have found in the "north" that the most conclusive identification features for poison ivy are the three leaves with redidsh sepals and stems (and yes, reddish new growth).  Although all the photos in our database show leaves that have notched edges, I have seen it with almost completely smooth leaf margins with perhaps only one notch.  I have also seen it look more like a zig-zag than a lobed edge.

My advice to you is ... if you think it might be, treat it like it is poison ivy.  Spray it with weed killer (using a paper bag or cardboard to protect adjacent plants) or pull it using what I think of as the dog-poop&scoop method.  When I lived in your area and used to find it popping up in my flower beds (the berries are a very important and plentiful food source for birds) I saved newspaper bags especially for pulling poison ivy seedlings as they are narrrow and protect your skin almost up to the elbow.  The plant can be pulled out, the bag turned inside out as you remove it and the whole business disposed of.

Wash your hands (and garden clothes) thoroughly immediately if you think you may have come in contact with poison ivy, even if you have no reason to believe that you might be allergic to it.