What is poison ivy?
Poison ivy is a very common plant found in most parts of the United States. It has 2 forms. One form grows low to the ground. It is usually found in groups of many plants and looks like weeds growing from 6 inches to 30 inches high. The other form is a "hairy" vine that grows up a tree. Both have stems with 3 leaves. You may have heard the old saying, "Leaflets three, let it be." This is because most people are allergic to poison ivy.
Written by familydoctor.org editorial staff