(Written by undergraduate student guest blogger from Byrne seminar Fall 2014 at Rutgers)
Ask any Boy Scout, backpacker, hiker, or avid outdoorsman what plant they’re most wary of, and the majority will give you the same answer: poison ivy. Toxicodendron radicans, more commonly known as poison ivy, is a flowering plant found in North America and Asia. It is well known for the itching, irritating, and occasionally painful rash contact causes in most people. This reaction is caused by urushiol, a clear liquid in the sap of the plant, which, contrary to popular belief, serves not as a defense mechanism but as a way to help the plant retain water. Because of the reaction it causes, poison ivy has gained a rather negative reputation in the eyes of most people. Various mnemonic devices, such as “leaflets three, let it be”, have been coined to help in identifying and avoiding it. There’s even a super villain from the Batman comics named after it.
copyright:Larry Korhnak (http://www.sfrc.ufl.edu/extension/4h/plants/Poison_ivy/)
Despite its negative effects on humans, poison ivy serves an important and beneficial role in the environment. The poison ivy plant produces whitish, waxy berries that develop in the summer and persist into the winter, providing a food source for a variety of wildlife, including deer, squirrels, insects, and more than 60 species of birds. Poison ivy is also very valuable to shoreline and coastal areas where, due to its salt tolerance and ability to grow in nutrient-poor soils, it plays an important role in preventing erosion and protecting sand dunes. Several species of moths also use poison ivy plants to shelter their larvae while they pupate.
So while poison ivy is considered a weed by most, it does have a positive side as well. It just goes to show that even the most harmful and unwanted weeds can have their pluses.