“Leaves of three, leave it be” is the old adage used to teach people how to identify and avoid an uncomfortable experience outdoors. However, the axiom is not completely accurate and quite a few plants with three leaves do not need to be avoided, like strawberries and raspberries. Learning to properly identify a few common plants is relatively simple and can help ensure a positive experience, or at least avoid a potentially uncomfortable one when venturing outside.
Poison ivy, poison oak and poison sumac are probably the most famous members of the “plants to avoid” list in North America. The sap of these plants contains the chemical urushiol which can cause an allergic reaction when it contacts the body. The reaction is often an irritating, itching rash that can develop into a more severe reaction in some people. When a plant is injured or damaged, urushiol is released to the plant’s surface. Urushiol is an oil that adheres to anything it comes in contact with including skin, blankets, clothing and pet fur.
|Photo from webmd.com|
Poison ivy is sometimes confused with other plants found in Ohio. Virginia creeper is a vine that often grows along tree trunks, similar to poison ivy, but contains 5 leaflets instead of 3 and the vine is “hairless.”
Both box elder, a member of the maple family, and fragrant sumac have leaflets similar to poison ivy. The leaflets of box elder saplings attach to the main stem opposite of each other, rather than in an alternating pattern like poison ivy.
Poison sumac is the only other of the infamous three plants that is found in Ohio. It is mostly confined to the northeastern part of the state, and even in that region it is a rare occurrence. Poison sumac is a shrub with leaves containing 7 to 13 oblong leaflets with smooth edges. The stems of the shrub are hairless. It is almost always found in wet locations, like sphagnum bogs, fens and swamps.
|Jewelweed or Touch-Me-Not|
So whether you are heading into your backyard or hiking deep into the back country, being able to identify a few common plants can have a dramatic difference on the outcome of your trip. If you are interested in learning more about Ohio’s wild plants, there are a variety of excellent field guides available as books or online. Although plant identification may seem overwhelming at first, a good field guide will help point you in the right direction.
Most photos were taken from The Ohio State University Extension or USDA websites.