Is it poison oak or is it poison ivy? Most people watch out for "leaves of three" but don't really know the difference. They do have in common the same rash-causing resin, called urushiol. Urushiol is found in all parts of the plants, even if the plant has died. Any interaction with the plant may cause your body to come in contact with urushiol.
So what is the difference between the two?
Poison ivy grows throughout North America and Canada, with the exception of Oregon. Alaska, Hawaii and California. Poison oak is found in Oregon, Washington, California and along the Atlantic Coast.
Both plants grow as a shrub or a climbing vine, but poison ivy may also grow as ground cover. The climbing vines are very difficult to identify in the winter when the leaves fall off - be careful when using firewood with vines wrapped around them!
Both plants grow as leaflets of three and vary in color from green to bright red as they change with the seasons. Poison oak leaves are shaped like a true oak with rounded tips where poison ivy leaves are more almond shaped and pointed at the ends.
Both plants produce berries. Poison oak has greenish white or tan berries, and poison ivy has greyish white berries.