Poison Ivy, also know as Toxicodendron radicans, is a poisonous North American and Asian flowering plant that is well known for causing an itching, irritating, and sometimes painful rash in most people who touch it, caused by a clear liquid compound in the sap called urushiol. Poison Ivy is variable in its appearance and habit, and despite its common name it is not a true ivy plant, it is most often thought of as an unwelcome weed.
FINALLY, How can I tell if it's Poison Ivy?
Poison ivy can be a bit of a chameleon. It looks similar to several common backyard plants including Virginia creeper and boxelder. The leaves of poison ivy may be shiny or dull and the leaf margins may be toothed or wavy, or have no teeth at all. The leaves may be hairy, or have no hairs at all. Its appearance can vary greatly, but in all cases it has compound leaves that consist of three leaflets. The leaflets are 2-5 inches long, green during the growing season and turning scarlet red in fall. The leaves are arranged in an alternate pattern on the stem. The terminal (end) leaflet has a longer stalk than the lateral (side) leaflets. READ MORE Info from msu.com